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Meet the Beetles

No, this is not an account chronicling a British invasion, especially during the month we celebrate the country’s 250th anniversary of its separation from commonwealth rule.  This is instead a short introduction to some of the numerous regional insects of the order Coleoptera.

Globally, there are somewhere between 300,000 and 2 million or more species of beetles, depending on who’s doing the enumerating.  A commonly settled upon number is 400,000, which makes beetles account for about 40% of the known insect species and 25% of the animals in the world.  In the United States, there are almost 30,000 species.

Morphological variation among individuals in a population of beetles is easily observed.  These differences often manifest into adaptations that provide a survival advantage and speciation.  It therefore comes as no surprise that beetles were among the life forms studied by Charles Darwin as he pondered natural selection and preparation of The Origin of Species.

Beetle Display at North Museum
During the nineteenth century, Professor Samuel Stehman Haldeman and other members of the Linnaean Society of Lancaster City and County made sizeable collections of beetles.  Haldeman mentored society treasurer Simon S. Rathvon’s interest in the insects and he in turn curated the 12,000 beetles in the society’s holdings.  The beetle case seen in the photograph is on display at the North Museum on the campus of Franklin and Marshall College in Lancaster.  Many of the Linnaean Society of Lancaster City and County’s specimens were moved from the custody of the college to the museum upon its opening in 1953.  (For more on the Lancaster Linnaeans, see our post from February 25, 2018, titled “A Century of Extinction” or, better yet, visit the North Museum.)

If it’s organic, living or dead, a beetle has probably become specially adapted to fill the role of reducing it or consuming it.  Beetles are indispensable members of the ecosystems they inhabit.  Many function as scavengers, breaking down dead plants or animals into the basic nutrients that renew life.  There are those that consume rotting wood, dung, and carrion.  Sometimes they eat these things when people would rather they didn’t—such as moist wood that’s part of a house.  Then there are species of beetles that are herbivores, consuming plants and parts of plants that got their energy directly from the sun.  There are beetles that eat stems, roots, leaves, buds, flowers, nectar, sap, seeds, and fruit—many specializing in particular plant species or families.  Some of these beetles come to our attention because their populations explode in response to our creation of monocultures of their favored food, but many more act as pollinators for plants critical to human survival.  Linnaean Society treasurer Rathvon made these herbivore-plant relationships the focus of many of his nineteenth-century writings, particularly as they affected agriculture.  On the upper trophic levels, there are the predatory beetles that feed on herbivores or other carnivores.  Many of these species have narrowed their choice of prey to one or fewer species.  For example, there is a beetle that feeds only on the subterranean nymphs of cicadas.

Beetles and Trophic Levels
Beetles occupy numerous trophic levels within the food chain.  Staghorn or stag beetle (Lucanidae) larvae are reducers that feed on rotting wood.  Meanwhile the adults, which are sometimes attracted to man-made lights, consume sap.  A herbivorous primary consumer, the Red Milkweed Beetle (Tetraopes tetrophthalmus), a member of the long-horned beetle family (Cerambycidae), feeds exclusively on  Common Milkweed.  Ladybird beetles (Coccinellidae), also known as ladybugs, are secondary consumers and favorites of gardeners due to their appetite for aphids throughout most of their lives.  (Click the image for a larger version)

Ladies and gentlemen, the beetles…

Dogbane Beetle
The Dogbane Beetle (Chrysochus auratus) is one of the leaf beetles (Chrysomelidae), a family which includes numerous agricultural pests.  However, as its name suggests, this beetle feeds on dogbane (Apocynum species), a milkweed-like plant of woodland edges and early successional habitats, so it poses no threat to crops or ornamentals.
May Beetles or Junebugs
The large family of scarab beetles (Scarabaeidae) includes dung beetles and other important detritus-feeding decomposers.  The may beetles, also known as junebugs, seen here are probably of the genus Phyllophaga, but species-level identification typically requires lab examination.
May Beetle or Junebug
Adult may beetles feed on a variety of leaves throughout the night.  The larvae consume the roots of grasses and other plants.  Neither life stage does significant damage, but skunks have a passion for digging in lawns to find the larval grubs.
May Beetles or Junebugs
Like the others shown in our images, these may beetles were photographed after being attracted to man-made lighting.  They’re frequently very noisy when tumbling in for a visit because their soft wing membranes, seen here protruding from the beetles’ posteriors, often tangle with their elytra, the hardened pair of front wings that make up over half of their armor-like dorsal surface when closed.
May Beetle or Junebug
A more colorful may beetle, aka Junebug.
Big Brown Bats
Big Brown Bats are the only commonly encountered flying mammal remaining in the lower Susquehanna valley.  To provide the nutrition and energy they need to raise young and store up reserves for hibernation, Big Brown Bats consume large quantities of night-flying scarab beetles (including Phyllophaga species) throughout the summer and fall.  In addition, their survival relies in large part upon the availability of adequate summertime birthing roosts in places like warm attics.  Later in the year, their needs shift to wintering sites in caves, mines, and quiet old cellars where they don’t need to share space with colonies infected by the fungus Pseudogymnoascus destructans, the pathogen that causes White-nose Syndrome (WNS), a fatal disease that has wiped out 95% of the bats in some hibernacula.  (United States Fish and Wildlife Service image by Pete Pattavina)
Adult Green June Beetles, also known as June Bugs, are often most evident in July.  These diurnal herbivores normally consume fruit like this watermelon only after it begins rotting or has been damaged by some other animal.  The larvae are mostly detrivores, specializing in consuming mold and humus, especially among the roots of plants that lie beneath layers of mulch or thatch.  The grubs are preyed upon by skunks, birds, and moles.
Striped Skunk
Skunks digging among grasses are often harvesting the larvae of many different species of scarab beetles.
Eastern Bluebird Eating Mealworm
Mealworms are the commercially raised larvae of the Yellow Mealworm Beetle (Tenebrio molitor), a species of darkling beetle in the family Tenebrionidae.  Perpetual pests in food storage, the grubs are now raised for research and as food for humans and insectivorous animals like this Eastern Bluebird supplementing its winter diet at our headquarters feeding station.
Click beetles (Elateridae) have an articulating prothorax that snaps and propels the insect into the air as a protrusion resembling a spine “clicks” into a furrow on its ventral surface.  These sudden launches can help the click beetle escape a potential predator.
Like the previous individual, this click beetle was attracted to man-made light.  The larvae consume small rootlets, seeds, and tubers in soil and among decaying organic matter.
Eyed Elator
Another member of the click beetle family, the Eyed Elator (Alaus oculatus) mimics the head of a snake or other predator to avoid assuming the role of victim.  The larvae feed among the stumps and roots of dead and dying forest trees consuming the larvae of wood-boring insects.
Six-spotted Tiger Beetle
The Six-spotted Tiger Beetle (Cicindela sexgutata) is a familiar sight on sun-dappled forest paths.  It is a fast-running predator, consuming ants, spiders, and other small arthropods.  The larvae ambush hunt from the entrance to their burrow, quickly snagging prey as it passes by.
Giant Water Scavenger Beetle
The aquatic larvae of the Giant Water Scavenger Beetle (Hydrophilus triangularis) are voracious predators consuming snails, other invertebrates, tadpoles, and even small fish.  In some waters, they may contribute to the control of mosquitos.  The adults are herbivores and scavengers.  Some, like this one, are attracted to lights at night.
Photinus Firefly
Fireflies, also known as lightning bugs, are renowned for their ability to produce a flash of light to attract a mate on a warm summer evening.  Both sexes of fireflies in the genus Photinus (seen here) produce pulses of yellow light through the chemical reaction known as bioluminescence.  Their larvae feed mostly on earthworms.  The genus Photuris includes the Pennsylvania Firefly (Photuris pennsylvanica), a species which is probably not particularly common in the keystone state.  Photuris flashes are greenish in color and begin a bit later, usually after dark.  Their larvae are scavengers, consuming fallen insects and fruits.  A third genus, Pyractomena, flashes amber light.  Its larvae consume snails and can be seen ascending vegetation above damp soil along quiet segments of the lower Susquehanna River at nightfall.  Want to see more fireflies around your place next summer?  Skip the the lawn treatments and let more space rewild to tall, mature grass and herbaceous growth, turn out the lights, then watch the magic.  The star-like twinkles of glowing beetles will be signaling, “I want to hold your hand,” throughout your private firefly refuge.
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It’s a Toss-up

Uncle Tyler Dyer is a bit of a numismatic.  He’s not invested in anything particularly valuable, but he enjoys filling books with examples of each year’s newly minted specie.  Earlier this month, he was perusing his fifty-year-old collection of coins from the bicentennial year of 1976, as well as his book of state and other commemorative quarters issued earlier this century, when he realized he hadn’t acquired a set of semiquincentennial metal.  After visiting a local dealer, he stopped by to show us the latest additions to his albums.  We found this five-cent piece to be particularly interesting…

2026 Buffalo Nickel
Uncle Tyler Dyer’s latest addition to his nickel folder.

Uncle Ty said he had never before come across a coin that was so well balanced—it’s ideal for tossing.  He purchased some extras to share and told us they’re great to carry around in case you’re ever wondering whether or not you’re keeping sufficient distance between yourself and the wildlife you encounter.  Just give the coin a tumble skyward and heads or tails, it always yields sound guidance.  And that’s no pile of buffalo chips!

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Smoke on the Horizon

This fire temperature enhancement of this morning’s National Oceanic and Atmospheric Administration satellite image of remote areas in western Ontario shows numerous large wildfires (indicated in red) burning north of Lake Superior.  Ablaze is an area of taiga, the boreal conifer and mixed forests that cover much of interior Canada.  The trees that grow in these wilderness areas are adapted to the large fires that regularly incinerate vast swaths of timber.  Two of the conifers, Black Spruce (Picea mariana) and Jack Pine (Pinus banksiana), require fire for regeneration and are often among the deciduous White Birch (Betula paptrifera) and Quaking Aspen (Populus tremuloides) that first recolonize burned acreage.  As succession proceeds, these pioneer species are followed by growth of Balsam Fir (Abies balsamea) and Northern White Cedar (Thuja occidentalis), both of which succeed Tamarack (Larix laricina) and Black Spruce in the sphagnum bogs there.  (Cooperative Institute for Research in the Atmosphere/National Oceanic and Atmospheric Administration image)
Just to the south of the area currently being impacted by wildfire, the Kirtland’s Warbler (Setophaga kirtlandii) nests only in young stands of Jack Pine in Michigan, Wisconsin, and Ontario.  During much of the twentieth century, this Neotropical migrant was in endanger of extinction, taking refuge during the breeding season in several areas of Michigan where large fires had cleared away climax forest and Jack Pines were allowed to regenerate.  Prescribed fire and block timber harvesting techniques now manage some lands specifically for Kirtland’s Warbler habitat.  The species was delisted from endangered status in 2019.  (United States Fish and Wildlife Service image by Vince Cavalieri)
Naturalized Northern White Cedar Growing in Rock
The Northern White Cedar is most familiar to residents of the lower Susquehanna valley as the arborvitae, an evergreen landscape tree that includes numerous cultivars and hybrids derived from the wild taiga conifer.  In suburbia, this tree is abused, planted in rows to create a fast-growing but short-lived windbreak or privacy screen.  How about mixing it up a little bit by adding some variety to those hedgerows?  Then, think about using these beautiful trees where they’ll thrive.  Northern White Cedar grows like a bonsai artist’s dream among boulders, an inspiration for mimicking their appearance in miniature, and will sometimes naturalize in this rocky terrain under mesic (moist) conditions.  Northern White Cedar is a bog species in its native range to our north, so you can give strong consideration to planting scattered specimens in the wet soils of your rain garden, riparian buffer, or other soggy spot.  Scatter some around, put a few in clumps, and enjoy the pizazz they can add to a dreary winter day!
White Spruce and Northern White Cedar
A look at Northern White Cedars in the susquehannawildlife.net headquarters tree nursery and, in the foreground, a White Spruce (Picea glauca), another common conifer of the boreal forests.  In our area, a miniature cultivar of P. glauca known as “Dwarf Alberta Spruce” is routinely planted as a landscape specimen.  On occasion, these compact plants will revert to their “wild” form and grow full-size branches to begin looking more like their ancestral parents.
The visible satellite image from just before 9 AM shows haze from the Ontario fires streaming into the northeastern United States and the Susquehanna basin.  The dense, river-like band of brown smoke seen barreling through New York and New England will shift south into our region during the remainder of the day, so slow down and take it easy.  How long will these fires burn?  Due to the zero-fire forest management strategies of the twentieth century, some areas of taiga haven’t experienced a burn for over 100 years.  The highly combustible fuel load of dry logs, limbs, and needles accumulates in these parcels with each passing year, adding to the threat of a greater frequency of explosive, far-ranging, catastrophic infernos.  To reduce the proliferation of fuels and to get the boreal forests back on the every-decade-or-so natural fire regime that keeps these biomes healthy and thriving, blazes in remote wildlands that haven’t been subjected to regeneration by fire for many decades are primarily contained to protect people, infrastructure, and unique native assets, but are mostly allowed to burn.  (Cooperative Institute for Research in the Atmosphere/National Oceanic and Atmospheric Administration image)
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Are Ants Invading your Summertime Picnic? Not in Our Neck of the Woods

If sprinkles of pepper are the only black specks you care to find in your potato salad, and if the only thing you want in your pants is you, then having a swarm of ants visit your outdoor feast is out of the question.  During our recent multi-day foray afield, ants were just a cupcake’s throw away, but none dared to scurry out from their hiding place to invade our spread.  Fortunately for us, the local anteater was on duty, snatching them up whenever they came into sight—and sometimes before.

Pileated Woodpecker
We’re all familiar with the Pileated Woodpecker, the prehistoric-looking, pterodactyl-like denizen of the forest whose appearance alone reminds us that birds are the surviving dinosaurs.
Pileated Woodpecker
And we’re all aware of the Pileated Woodpecker’s fine-tuned abilities to identify stressed, weakened, and dying trees where it not only chisels out cavities for roosting and nesting, but also finds much of its food.
Pileated Woodpecker
Pileated Woodpeckers don’t eat wood, but spend much of their time searching trees from top to bottom for infestations by the insects and insect larvae that are in the process of reducing the cellulosic fibers and other components of dead and dying trees into matter that will be recycled into growth medium and nutrients for surviving plants of the forest.
Pileated Woodpecker
That search may involve excavations deep into the rotting pulpwood.  But many times, the target of the Pileated Woodpecker’s hunt is right among the bark…
Pileated Woodpecker
…where the prey can be snatched up with its probing tongue.
Carpenter Ants
Carpenter ants (Camponotus species) don’t eat wood, but instead excavate extensive nests called galleries in damp and rotting timber.  Considered both predators and scavengers, they get most of their nourishment by harvesting nectar from flowering plants, by extracting the gooey tissues and liquids from dead insects, by using their antennas to coax honeydew from the aphids they farm, and by carrying away sweet treats unwittingly provided by humans.  The Pileated Woodpecker’s long anteater-like tongue is an adaptation for feeding on these ants and other creepy crawlies.  Carpenter ants often make up a majority of a Pileated Woodpecker’s diet, particularly during the warmer months of the year.  They are one of the first foods young woodpeckers can easily locate and consume on their own.  During the colder months, when ants can be harder to find, Pileated Woodpeckers seek out overwintering beetle grubs and other larvae while also foraging for energy-replenishing berries including Poison Ivy, wild grape, and bittersweet.
Pileated Woodpecker
A Pileated Woodpecker alert for the movement of carpenter ants among the folds of bark on this pine tree.
Pileated Woodpecker
The ant-eating Pileated Woodpecker in action, keeping the little sugar junkies at bay so that the only thing covering the ground during your outdoor luncheon is a gaudy picnic blanket.
Pileated Woodpecker
Your local Pileated Woodpecker, he’s more than just a pretty face.
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This Independence Day, Don’t Fall Victim to the BOMBs

Bicentennial Flag Display
It’s the 50th anniversary of the American Revolution Bicentennial.

The gasoline and gunpowder gang’s biggest holiday of the year is once again upon us, so we’ll take this opportunity to pass along the same advice we offered last year…

“This Independence Day weekend, don’t let the celebration turn to tragedy. Keep a garden hose or fire extinguisher at the ready to dowse any hot embers or other potential troublemakers.  Fill a bucket with water for use as a trash receptacle for your hot sparkler rods and other pyrotechnic waste.  Have non-combustible lids or covers handy to smother any flare ups while you’re grilling.  Don’t forget, they’ll be plenty of testosterone and adrenaline circulating to keep the festivities exciting, so skip the alcohol and energy drinks if you’re driving or lighting off fireworks; things don’t need to be any more explosive.  And remember, the anthem’s lyrics say, “…the rockets red glare, bombs bursting in air…”, not burning your neighbor’s garage down, so maintain a safe distance with your grills, camp fires, and July 4th displays, won’t you please?”

Perhaps you don’t consider yourself part of the gasoline and gunpowder subculture and think yourself immune from the threat of fire this weekend.  Well, think again.  The period coinciding with the Independence Day observance during 2026 has the potential to see more fires started by BOMBs (Battery Operated Motorized Bikes) and other lithium-ion powered conveyances, tools, and electronics than ever before.  The popularity of these fast-charging devices has placed them in almost every home and workplace in the region.  As more and more of them come into daily use, the frequency of battery failures resulting in sometimes catastrophic fires is escalating.

(United States Fire Administration image)

Recharging lithium-ion powered bikes and other devices inside of occupied buildings (or garages and sheds attached to occupied buildings) is risky business.  Never charge or store an e-bike in a doorway, stairway, hallway, or other egress route within a structure.  When not in use, consider keeping and re-energizing these conveyances in buildings or designated places detached from occupied spaces, preferably in non-combustible surroundings.  The London Fire Brigade offers these helpful tips for charging e-bikes and e-scooters.

E-bikes can be incendiary.  Avoid storing and recharging BOMBs among combustibles in dwellings and elsewhere.  (United States Department of Transportation/National Highway Administration image)

The United States Fire Administration provides these quick tips to improve safety when using lithium-ion powered devices…

Recycle or dispose of faulty batteries properly.  (United States Fire Administration image, click for animation)
Don’t overheat your batteries.  (United States Fire Administration image, click for animation)
Practice the same caution when recharging them too.  (United States Fire Administration image, click for animation)
Charging on a Tile
Our charging station at susquehannawildlife.net headquarters consists of a ceramic tile repurposed from our days in the lab, but any piece of flat stone or tile will do.  It allows the device good air flow to dissipate heat while re-energizing.  To act as a heat sink, the non-combustible tile itself stands on short feet above the table upon which it rests.  This setup works great for tablets, phones, and other small devices.  If we were to recharge an e-bike, e-scooter, or other BOMB, it would either be located outdoors or in the garage on a concrete floor beneath the automatic fire sprinklers.

Remember: while you’re recharging them, treat lithium-ion powered electronics like food on the stove—never sleep or leave them unattended.

Be safe and have a memorable weekend!

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Swarms of Sulfurs

Balmy evenings and rising stream temperatures are yielding some sizeable flights of mayflies collectively known as sulfurs.  These nuptial displays are most conspicuous as swarms attracted to bright lights near the waterways where the aquatic nymphs spent the past year or more before emerging to take wing for their brief period of adulthood.  During the past two nights here at susquehannawildlife.net headquarters, we’ve noted what appear to be three different species of these tiny sulfurs gathering on the walls and doors below entry lamps.  Each is referred to by anglers using the common name “Pale Evening Dun”.

Sub-adult (Subimago) Leucrocuta aphrodite
Flat-headed mayflies we believe to be Leucrocuta aphrodite, this one a subimago (sub-adult) yet to undergo its final molt, continue their emergence for a third week.
Adult (Imago) Leucrocuta aphrodite
Just one of many imago (adult) Leucrocuta aphrodite mayflies seen paying us a visit.
Sub-adult (Subimago) Leucrocuta minerva
Though similar in size to the prior specimens (about one half inch in length), this flat-headed mayfly subimago (sub-adult) may be a different species, possibly Leucrocuta minerva.  We first noticed the arrival of these mayflies early last evening.
Adult (Imago) Leucrocuta minerva
A possible imago (adult) Leucrocuta minerva.
Sub-adult (Subimago) Ephemerella dorothea
Like the preceding mayflies, this sulfur is also referred to as the “Pale Evening Dun”, though you’ll notice it has three tails instead of two and is noticeably larger, approaching one inch in total length.  Unlike the flat-headed mayflies (family Heptageniidae) which possess compressed bodies for clinging to rocks and other substrate in the riffles and pools of high-gradient streams, this spiny crawler mayfly (family Ephemerellidae) inhabits lower-gradient waters where it not only clings, but crawls and swims as a means of locomotion.  The subimago (sub-adult) seen here is a member of the genus Ephemerella, probably the species E. dorothea.  To many fly-tying anglers, it is also known as the “Pale Morning Dun”, the “Little Sulfur Mayfly”, or the “Summer Mayfly”.
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Photo of the Day

Dusky-tailed Sunflower Aphids (Uroleucon obscuricaudatum)
What happens when a single native plant species like this Oxeye (or False Sunflower) becomes exceptionally common in a forest margin?  Well, that stand of Oxeye becomes vulnerable to a runaway infestation of sap-sucking insects like these colorful Dusky-tailed Sunflower Aphids (Uroleucon obscuricaudatum).  Because each of our many native aphid species specialize to feed on only one species, genus, or family of plants, these localized aphid booms seldom threaten the overall population of the host.  Aphids target soft new growth, so plants that escape infestation in the early part of the growing season have a chance to harden off and thereafter flower, seed, and mature unscathed by these little suckers.  After all, if a specialized feeder like the Dusky-tailed Sunflower Aphid wiped out all of the sunflowers and false sunflowers in its range, Dusky-tailed Sunflower Aphids would cease to exist.  Look at it this way, aphids do a little thinning to help promote plant diversity in their landscape.
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Fishwatching on a Coldwater Stream

What better way to pass a bright, sunny afternoon than to beat the heat by loafing atop a bridge spanning a small coldwater stream?  We just lingered in the shade cast by an overarching tree and watched to see what might come by…

Eastern Blacknose Dace
The Eastern Blacknose Dace is the most widespread and usually the most numerous minnow in coldwater streams throughout the Lower Susquehanna River Watershed.  Sightings from our lookout at a crossing on the East Branch Standing Stone Creek, a tributary of the Juniata River, were in accordance with this generalization.
Tessellated Darter and Eastern Blacknose Dace
The presence of these Eastern Blacknose Dace in close proximity to a male Tessellated Darter’s nest has him unfurling his flag-like dorsal fins in an attempt to intimidate the much larger minnows.
Tessellated Darter and Eastern Blacknose Dace
He won’t be fully satisfied until they leave the area, so he’ll keep displaying his banners.
Tessellated Darter
Satisfied the invaders are gone, at least for now, he secures his sails, but continues to stand watch over the eggs, which are probably concealed beneath the boulder on the right.
White Sucker
As it searches for invertebrates and other sources of food along the bottom of East Branch Standing Stone Creek, a juvenile White Sucker stirs up organic material derived chiefly from fallen leaves and other plant matter.  Draining exclusively from dense woodlands in Rothrock State Forest, this waterway collects minimal quantities of water-polluting nutrients and sediments.  The substrate is mostly sand, gravel, and cobble among boulders of various sizes.
Rainbow Trout
Except for some stormwater runoff from forest roads in its headwaters, the first significant source of thermal pollution on East Branch Standing Stone Creek as it tumbles toward the Juniata is a recreation impoundment at Greenwood Furnace State Park.  This Rainbow Trout, which was probably stocked there for angling earlier this spring, is already showing the effects of warming water.  As lake temperatures rise into and above the mid-seventies, trout become stressed and are especially susceptible to other factors that can prove fatal.  These include parasites, poor nutrition, bacterial and fungal infections, and predation.  Because they require well-oxygenated water to survive, trout are especially vulnerable to diminishing oxygen levels in warming and/or polluted waters, so hypoxia is a real concern.  From our lookout just upstream from the lake, we watched as this struggling Rainbow Trout, apparently seeking refuge from the mid-day conditions in the sun-drenched impoundment, ascended the cold stream and took cover in some shade.
Juvenile Brown Trout
In waters up the creek from the lake, trout with smaller proportions than those typically stocked for angling have been able to not only survive year-round, they are reproducing there.  From our perch over East Branch Standing Stone Creek, we quietly observed this juvenile Brown Trout, a descendant of non-native individuals introduced in an attempt to establish a population of “wild trout” in the waterway.
Juvenile Brown Trout
Brown Trout spawn in East Branch Standing Stone Creek in November.  The eggs hatch within a month or two and the fry hide among the gravel, cobble, and rock of the stream bed.  Still in its first year of life, this juvenile already resembles an adult, only traces of the vertical bars called “parr marks” remain along its flanks,…
Juvenile Brown Trout
…but this is still a petite little fish.  Compare it to the walnuts on the stream bottom to the right.  In a small stream, Brown Trout reach sexual maturity at a very small size, but could be in their third or fourth year of life when it happens.
Juvenile Brook Trout
A population of the Susquehanna watershed’s native salmonid, the Brook Trout, lives and reproduces in East Branch Standing Stone Creek as well.  This juvenile began life in much the same way and at about the same time of year as the non-native Brown Trout with which it will have to compete for survival.  However, we noticed that this fingerling’s change in physical appearance is not as expedient as that of its introduced competitor.  While telltale signs of an adult “brookie” are starting to show, the vertical “parr marks” of a young trout are still quite apparent, and will likely remain visible throughout its first year and beyond.  Later in the summer, the dorsal surface of this fish will darken and the vermiculations of an adult Brook Trout should become evident.  Most Brook Trout reach sexual maturity during their second year of life, so if all goes well, this could very well be one of next year’s breeders.

Greenwood Furnace State Park and East Branch Standing Stone Creek are located within Rothrock State Forest in northeastern Huntingdon County, Pennsylvania—just over Stone Mountain north of Belleville and the Kishacoquillas Valley on PA Route 305.  To identify fish and other aquatic life in clear waters, you’ll need only a pair of close-focus binoculars or a camera with a telephoto lens.  Polarized sunglasses really help penetrate the surface glare and shimmer, particularly on breezy days, making them a great fishwatching accessory for spotting your subjects of study.

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Photo of the Day

Adult Male Five-lined Skink
Even while posturing with legs and feet held along his flanks so as not to scorch his sensitive little toes on the hot, sun-drenched log, this adult male Five-lined Skink is master of his domain, allowing no other adult males to enter his protectorate.  Only juveniles and adult females sporting bright blue tails earn his forbearance and are permitted within his realm.  With a diet consisting almost entirely of arthropods including insects, Five-lined Skinks are valuable residents around the garden and farm but are seldom found there due to their extreme sensitivity to the use of pesticides including both insecticides and herbicides.
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Good News and Bad News

Axanthic Eastern Garter Snake
The good news is that following a forty-year period without seeing this rarity, we were delighted to finally have the opportunity to observe one again.  The bad news is that it was found flattened like a pancake on a street next to a construction site.  What is it?  To find out, go to our reptiles page by clicking the “Reptiles” tab at the top of this page, then scroll down until you find this same photograph there. 
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Mayflies and Hitchhikers

Month-by-month and week-by-week changes in water temperatures and other stream parameters trigger the date-specific emergence of flights of particular species of mayflies from the lotic waters where they spend a year or more feeding and growing as substrate-dwelling nymphs.  For each individual mayfly, these nuptial flights are only days in duration and include a molt from the sub-adult (subimago or dun) stage to the adult (imago or spinner) stage.  Mayflies do not feed during these flights, their sole intention is to mate and reproduce.  Conspicuous transitions of large numbers of nymphal mayflies into flying sub-adults are often referred to as “hatches”.  So, what’s hatching right now?  As local streams reach the upper sixties and seventies, we’ve noticed this mayfly gathering on walls and windows illuminated by man-made light, sometimes a half mile distant from the waterway where they spent the past year or more as a nymph before first taking flight…

A subimago Leucrocuta aphrodite
A possible subimago (sub-adult) Leucrocuta aphrodite, a flat-headed mayfly sometimes called the “Pale Evening Dun”, a common name applied primarily by fly-fishing anglers to several not-so-closely-related genera of mayflies also collectively known as sulfurs.  Flat-headed mayflies (family Heptageniidae) are adapted to nymphal life in stream riffles where their low profile helps them cling to the rocks where they feed.
Leucrocuta aphrodite Exuvia with a phoretic mite.
Soon after taking flight, the sub-adult (subimago) Leucrocuta aphrodite molts into a second flying stage, that of the breeding adult (imago), leaving behind its final exuvia.  This particular exuvia has a stranded hitchhiker on the abdominal section.  Phoretic mites (Acariformes, in part) are thus named because they practice phoresy, attaching to hosts for no other purpose than transportation.  Just how small is this little, red-brown mite?  Well, the entire mayfly, including tails, is only about one-half-inch long.
Adult (Imago) Leucrocuta aphrodite
Freshly molted adult (imago) Leucrocuta aphrodite mayflies spend the day drying out and saturating all their tissues with blood before the search for a mate commences at dusk.  Fertilized eggs will be deposited in flowing waters suitable for development of the nymphs.
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Sunfishes of the Lower Susquehanna River Watershed

Throughout the lower Susquehanna basin, four commonly encountered Lepomis sunfishes are gathering in the shallows of lakes and ponds and in the pools of the regions streams and rivers to spawn.  As water temperatures surge into the upper sixties and seventies, you’ll see them from the shoreline as the colorful male sunfish clears a nest depression to attract and court one or more egg-laying females.  After the eggs are laid and fertilized, the male relentlessly guards the nest against trespassers, which can include other males protecting their scrapes located just a few feet away.  A colony of nesting sunfish can include multiple species—hybridization does occur.

So grab a pair of close-focusing binoculars or a camera and go take a look.  Because they generally thrive in clean, warmwater streams, you might be able to find all four of these Lepomis sunfishes in the waters near you.

Lepomis Sunfishes of the Lower Susquehanna
Fishwatching 101-  These four species of Lepomis sunfishes are found throughout the lower Susquehanna watershed.  The Pumpkinseed and the Redbreast Sunfish, both natives to the river and its tributaries, may be the most beautiful fish found in our region.  Click the image to see an enlarged version marked with key field identification points.
Largemouth Bass
While you’re searching for sunfish, don’t be surprised to find Largemouth Bass, another native transplant introduced from the Mississippi River drainage basin, lurking in the shallows.  Their spawning period began as water temperatures reached the low sixties.  Soon, they and their young will be feeding on the newly-hatched sunfish produced in nearby nests.
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Photo of the Day

Great Crested Flycatcher
Just when we thought the northbound migration of Neotropical songbirds had come to an end, we spotted this mid-morning arrival atop the Eastern Hemlocks in the urban susquehannawildlife.net headquarters garden: a Great crested Flycatcher.  Its visit was momentary, the paved parking areas, busy streets, and treeless lawns surrounding our little oasis giving it little reason for lingering.  But it was, nevertheless, a reminder of the Yogi’s words of wisdom, “It ain’t over ’til it’s over.”
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The Stewards of Inland Shorebird Habitat

As they travel between coastal wintering ranges and breeding territories in Canada and Alaska, vast numbers of shorebirds pass through the lower Susquehanna region each spring and fall—though few stop here to rest, feed, and provide us with an opportunity to observe them.  Prior to the construction of man-made dams and other alterations on our lotic (flowing) waterways including the river, shorebirds took advantage of lateral bars, stream deltas, and other alluvial deposits as places to loaf and re-energize.  Before they were drained and filled, some of the valley’s wetlands probably included sparsely vegetated flats where shorebirds could drop in for a brief visit.  Previous to their extirpation from our region, North American Beavers were the primary providers of quality habitat for shorebirds and other migrating waders on our lotic waters.  Their widespread network of dams, pools, and marshes maximized floodplain function by keeping streams thoroughly connected to their wetlands, nurturing plant communities that not only provided food and shelter for the beavers and other wildlife, but provided superb buffering against erosion while protecting against sediment and nutrient imbalances in lower Susquehanna waterways.

Beaver Dam and Lodge
Beaver dams need not be large, particularly on low-gradient streams where a structure like this is sufficient to create a pool with depth adequate for building and maintaining a lodge and transporting leafy branches and other food items by water.
A beaver lodge assembled in a pool with less than three feet of water, deep enough to provide the family with a measure of protection against terrestrial predators.
Beaver Pool
Beaver pool ecosystems provide homes for hundreds of species of plants and animals, including migrating shorebirds and other waders.
Solitary Sandpiper
Mud flats in the margins between emergent shrubs and herbaceous plant growth attract migrating shorebirds like this Solitary Sandpiper to the abundance of invertebrate life.  Seasonal movements of migrating shorebirds regularly coincide with the reductions of water levels in beaver pools which typically occur between May and September each year.
Least Sandpiper
During its southbound migration in September, a Least Sandpiper searches for arthropods and annelids as it visits a food-rich puddle along the periphery of a beaver pool.
Pectoral Sandpiper
A Pectoral Sandpiper feeds in shallow water near a stand of Common Cattails in a beaver pool.
Sora
During migration, rails including the Sora are attracted to dense emergent vegetation in beaver pools.  Some will nest in these rodent-managed refugia.
Green Heron
Green Herons visit beaver pools during migration and, due to the reliability of the food supply, will often nest in their vicinity.

So how did this happen?  How did the North American Beaver become a keystone species—an animal upon which the majority of other life forms within its ecosystem are so reliant?  Well, it’s largely due to the fact that our beavers aren’t particularly fond of a constant stream of noise.  More specifically, they don’t like the sound of running water in places where they intend to build and maintain a lodge.  And so, as they begin to place sticks, mud, limbs, stones, and other materials within a noisy riffle on a stream, they create a dam, and behind it a pool—a pool that is particularly advantageous for protecting their home and providing a means of conveyance for their construction materials and food supplies.

Cascading Series of Beaver Pools
On a high-gradient segment of stream, beavers will create a cascading series of pools. Because water filters through a beaver dam instead of spilling over it, the work of these meticulous rodents soon silences the sounds of water changing altitude.  No more sonorous riffle.
Beaver Dam
Quiet please.  High seasonal stream flow and damage from storms may create areas where water begins to erode the structure of the dam.  Where this condition persists, an adult beaver will soon mend the breach, just to quiet things down.  Why would beavers demand such a hush upon their domain?  Well, they have poor eyesight, but their hearing is excellent, and they rely upon it to detect danger.
Louisiana Waterthrush
The Louisiana Waterthrush (Parkesia motacilla), one of our earliest-arriving warblers, nests in forests along clear, high-gradient streams.  In mid-April, we found this individual and three others squabbling over a breeding territory adjacent to the series of cascading beaver pools shown in the previous images.
Brook Trout and Blacknose Dace
Native denizens of coldwater streams, neither the Brook Trout nor the Eastern Blacknose Dace has any difficulty finding its way through the voids in beaver dams to ascend and descend the sequence of pools.
Beaver Dam and Pool on Low-gradient Stream
On a low-gradient segment of stream, a dam just over a foot in height may be sufficient to create a beaver pool of considerable size.  Resembling the water-logged muskeg of the far north, well-established beaver pools form boggy habitats familiar to migrating shorebirds.
Water levels in the pools usually drop along with the stream’s base flow as soon as the effects of the spring thaw and rain showers subside.  Feeding areas in shallow water and on muddy ground are often revealed just in time for northbound shorebirds and other waders to stop by in late April and May.  These conditions often persist through the growing season and the fall migration of these birds which begins as early as late June and sometimes extends into October.
Tree Swallow at Natural Cavity
Where the pool inundates standing timber such as Red Maple and other species not used by beavers, the dead snags provide vital feeding areas for birds and other wildlife.  Cavity nesters like this Tree Swallow seldom find suitable natural housing elsewhere.
Eastern Newts Among Alderfly Exuvia
The mosaic of marshlands and braided stream channels within the beaver pool complex supports an abundance of aquatic life including these breeding Eastern Newts, seen here surrounded by the exuvia left behind following a massive hatch of alderflies (Sialinae).  Alderflies are a stream inhabitant during their larval stage and are indicator of clean water conditions.
A modern-day example of the way fully functional stream floodplains used to look in the Lower Susquehanna River Watershed.  Though the pools may appear pond-like during the cooler and wetter months of the year, by summer the water levels behind the beaver dams recede as the base flow of the stream wanes.  Now the true nature of the marsh, shallow pool, and braided stream complex is revealed.  Unlike most man-made dams that set a fixed pool elevation regardless of flow by discharging water over the top of the structure or through a spillway or gate, beaver dams merely throttle the flow through their porous construction.  Unless the beaver begins plugging small leaks as fast as the stream flow ebbs, the water level in the pools will drop.  So they’re not left high and dry, lodges are located in the deepest pools, usually in close proximity to the dam and/or one of the stream courses.  Though not inundated during the dry season, the soil in the pool complex is almost always damp and plants grow vigorously there, sequestering nutrients and retaining sediments in beneficial deposition patterns that actually inhibit erosion of the riparian landscape.  These streams and floodplains retain their hyporheic zone and freely exchange water with the underlying water table and aquifer.  It’s the ultimate floodplain management system, and the beavers don’t even know their doing all the work.  (Google Maps base image)
Where another high-gradient segment of stream enters the main pool complex, beavers have created an additional series of cascading pools.  The impoundments created by these dams help diffuse stormwater energy and process more nutrients and sediments within the floodplain’s wetland vegetation system.  (Google Maps base image)
Sandhill Cranes in Beaver Pool
Beaver pools often refill as stream flows increase following autumn rains.  The stockpiles of vegetative foods that grew within the beaver’s domain through the summer then become flooded and are a prime source of nutrition for not only the beavers, but waterfowl during both their autumn and spring migrations.  Gleaning and probing Sandhill Cranes often find these habitats to their liking as well.

While North American Beavers have returned to the region, most live as “bank beavers”, residing in the river and larger creeks of the valley where they excavate shelters among the roots of Black Willows and other shoreline trees and shrubs.  Floodplain encroachment, legacy sediment deposits, and just plain human intolerance have all conspired to prohibit North American Beavers from performing their magic on smaller local streams.  For migrating shorebirds, this continued absence of beaver dam ecosystems has turned much of the lower Susquehanna valley into “flyover country”.  Those travelers that do stop to rest and feed concentrate at the few favorable locations such as the lateral bars and the hydroelectric dam-created delta at the Conejohela Flats on the river in Lancaster County.  But centralization has its drawbacks.  Migrants spending time at concentration points may have a greater chance of contracting and spreading disease.  Protracted heavy foraging can degrade these habitats.  And over time, features such the lateral bars and delta deposits, including those on the Conejohela Flats, transition into other habitats—riparian forests.  A more widespread selection of favorable stopover points for shorebirds, waders, waterfowl, and other migrants is certainly desirable.

IMITATION IS THE SINCEREST FORM OF FLATTERY

Until public sentiment sways in favor of the North American Beaver, wildlife managers are mimicking some of the attributes of their sound-inspired installations.

New Impoundment at Middle Creek Wildlife Management Area
Created by excavating a depression in heavy clay soils, this new impoundment at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area collects water directly from rainfall and from surface runoff.  Its depth at no point is greater than about two or three feet.  During the driest times of the year, this space will be a mudflat, and a haven for migrating shorebirds.

Shallow-water conservation impoundments designed, constructed, and managed for migratory waterfowl and waders including shorebirds are not what we typically refer to as ponds—though they are lentic (still) waters.  Similar shallow freshwater impoundments at our National Wildlife Refuges are referred to as pools by the United States Fish and Wildlife Service, but smaller versions like this example at Middle Creek very closely resemble the prairie potholes created by glacial scour in the north-central United States and adjacent portions of Canada.  Many populations of migratory birds are familiar with pothole ecosystems and, like the beaver pools and marshes, have relied upon them as waypoints along their journeys for centuries.

Pond and Lake Zonation
Impoundments most beneficial to migrating waterfowl and waders including shorebirds are shallow in depth.  They lack the deeper waters of a pond or lake and thus have no limnetic (open water) or aphotic zones.  Managed throughout as a littoral zone, impoundments grow plants in shallow water or on damp soil through the summer months to chew up nutrients accumulated in waste deposited by visiting birds.  This vegetation is then flooded from late fall through early spring as forage habitat for migratory waterfowl.  The timing of the fluctuations in water levels approximates those of the beaver pools and marshes on lotic (flowing) waters.
Impoundment Gate
A gate assembly is a water control structure installed to provide seasonal management of the water levels in a conservation impoundment.  More than once, beavers have heard the sounds of tumbling waters inside these types of devices and tried to dam them up!

You’ve heard the line, “If you build it, they will come.”  Well, it’s true.  Here is a sample of the activity witnessed during the past two weeks at the new impoundment completed just several months ago at Middle Creek Wildlife Management Area along the tour route just beyond the “Stop 3” overlook.

Snow Geese
The ubiquitous Snow Geese were among the first migratory occupants of the new impoundment.  A few are currently lingering in the vicinity.
Blue-winged Teal
Ducks soon followed.  These Blue-winged Teal were among the last to pass through earlier this month.
Wilson's Snipe
Wilson’s Snipe were among the first species of migratory shorebirds to visit the new impoundment at Middle Creek…
Killdeer
…as were Killdeer, a species which nests nearby.
Least Sandpipers
Then, earlier this month, flocks of shorebirds including these Least Sandpipers were arriving to feed and rest.
Least Sandpipers
Least Sandpipers search for small invertebrates in shallow water and exposed soil.
Least Sandpiper and a Semipalmated Sandpiper
A Least Sandpiper (left) and a Semipalmated Sandpiper (right).
Solitary Sandpiper
Not all shorebirds seen by themselves are alone, and that includes the Solitary Sandpiper.
White-rumped, Least, and Solitary Sandpipers
Here’s a Solitary Sandpiper (right) feeding alongside a Least Sandpiper (center) and a White-rumped Sandpiper (left).
Least Sandpiper and a White-rumped Sandpiper
A Least Sandpiper (left) and a White-rumped Sandpiper (right).
White-rumped Sandpiper
Rare in our area during spring, the White-rumped Sandpiper (Calidris fuscicollis) flies north using the central flyway, then heads south along the Atlantic flyway in the fall, when it tends to be more regular here.
Spotted Sandpiper
Rocking and teetering along as it looks for food, the Spotted Sandpiper may be one of the easiest of shorebirds to identify.
Dunlin
Chunky little Dunlin (Calidris alpina) with their conspicuously down-curved bills are another easy-to-identify species, particularly in the spring when their breeding (alternate) plumage includes a black belly.
Black-bellied Plovers
Black-bellied Plovers acquire a handsome set of plumage in the spring as well.
Killdeer
Killdeer too are plovers and this pair appears to have taken up residence on barren ground along the periphery of the new impoundment.
Semipalmated Plover
The Semipalmated Plover doesn’t have nearly the flair for ornament its close relatives the Killdeer do; these little shorebirds wear only one ring around their neck instead of two.  Think this plover is cute?,…
Killdeer
…then check out this newly hatched Killdeer.  It starts life with just one necklace too, but acquires a second as it grows.  Look at those legs!  (If you visit the new impoundment at Middle Creek, drive slowly and please watch where you’re going.  Baby Killdeer and other young birds, as well as mammals and turtles, are commonly crossing the paved surfaces right now.)
Lesser Yellowlegs
Speaking of legs, here’s one of dozens of Lesser Yellowlegs that visited the new impoundment during their recent northbound travels.
Greater Yellowlegs
Though less numerous than the smaller Lesser Yellowlegs, a Greater Yellowlegs seldom goes unnoticed when dropping by the man-made pothole habitat.
Greater Yellowlegs
Have trouble telling a Greater Yellowlegs like this one from a Lesser Yellowlegs?  Look for the heavier, longer bill on the former, as well as dark barring along its flanks below the wings while the bird is in breeding (alternate) plumage during the spring migration.
Wilson's Phalarope
Everyone likes to see something unusual every now and then, and this impoundment delivers.  Just yesterday, we photographed this migrating Wilson’s Phalarope (top center) among two Least Sandpipers (top left and right), a Lesser Yellowlegs (left and slightly forward of the phalarope), and a White-rumped Sandpiper (foreground).
Wilson's Phalarope
Renowned for spinning in circles as they feed in shallow water, Wilson’s Phalaropes (Phalaropus tricolor) passing through the lower Susquehanna basin are headed toward nesting areas in the prairie wetlands, including potholes, of the northern United States and adjacent sections of southern Canada.

Species of wildlife in addition to shorebirds and waterfowl have already found the new impoundment favorable…

Spot-winged Gliders
Pairs of breeding Spot-winged Gliders (Pantala hymenaea), seen here in tandem while ovipositing, were swarming the impoundment after arriving earlier this week.  These dragonflies are ofttimes unpredictable nomads and are similar in appearance to the usually more numerous Wandering Gliders.  To recolonize seasonal portions of their range, both are famous for hitching a ride en masse on storm systems.  They share the behavior of finding ephemeral and new bodies of water favorable for egg laying due to their low density of aquatic predators.
Snapping Turtle
We watched this Snapping Turtle arrive to apparently find the newly created waters to its liking.  Snapping Turtles are important consumers in a wetland ecosystem.  Larger specimens may fill the role of an upper trophic level or apex predator, eliminating vulnerable mid-level consumers including other Snapping Turtles.
American Pipit
Because it bounces its tail up and down like a Spotted Sandpiper, you may at first glance mistake an American Pipit for a shorebird.  Long known as the Water Pipit, these songbirds have been visiting the impoundment while migrating north and stopping to feed in nearby croplands.
Glossy Ibis
Seen here with Least Sandpipers is a visiting Glossy Ibis.
Glossy Ibis
Sometimes twenty or more of these mostly coastal waders have made a pit stop at the “new Middle Creek pothole”, though none have thus far chosen to remain long.  Apparently, food sources sufficient to sustain a bird of their size have yet to develop in its benthos.
Western Cattle Egrets
Western Cattle Egrets visiting Middle Creek this spring have been frequenting the new impoundment.
Western Cattle Egret
With still little in the way of insects such as grasshoppers available in the surrounding landscape,…
Green Frog
…cattle egrets are looking to find prey like this Green Frog.
Western Cattle Egret
Many have been observed hunting the adjacent grasslands..
Western Cattle Egret
Where small mammals, mostly Meadow Voles, are being taken in abundance.

Managing saturation levels in shallow-water impoundments to resemble the seasonal variations in beaver pool and marsh systems can create lush growth and wildlife-rich environments.  Take a look at some images from a project in a headwaters area of a tributary to Conewago Creek (west)…

Well-established Shallow-water Impoundment
By late July, southbound shorebirds were already using these mudflats to feed and rest.  Other sections of the impoundment were dense with emergent and aquatic plants, the latter kept hydrated in deeper pools of the project by the inflow from several captured springs that supplement direct rainfall and sheet runoff to supply its water.  During a seasonal drawdown, the exposure of the impoundment’s soils to direct sunlight can provide a measure of disinfection to reduce the chances of disease transmission among its populations of visiting birds and other animals.
Water Lily Growth
In the deeper pools of the impoundment, water lilies and other aquatic plants grow in lush mats to provide cover and feeding areas for resident populations of breeding reptiles and amphibians.
Green Heron
An abundance of foods are available for waders including this Green Heron…
Immature Little Blue Heron
…and this immature Little Blue Heron, a wanderer typical of more southern latitudes.
Sandhill Cranes
While walking the road among tall grasses in the supporting landscape surrounding this impoundment, we were at first startled when these Sandhill Cranes strode by going the other direction.  We quietly kept moving,…
Sandhill Cranes
…then spotted them again as we looked across the impoundment to realize they weren’t alone, but were escorting a colt.
Sandhill Cranes with Colt
The hatching of this colt is testimony to the vital role wetland ecosystems play in the lives of hundreds of species.  Whether they be beaver pools and marshes on lotic waters or man-made shallow lentic waters, each of these habitats is filling a void that left floodplains and other critical lowland biomes faltering.  While they can’t replace the full-function floodplain management provided by an active beaver colony, shallow-water impoundments can provide relief for habitat-starved populations of the animals and plants that rely upon them.  A constellation of these projects on lands public or private across the lower Susquehanna watershed could help provide refuge for many of our flora and fauna with the most desperately fragmented of ranges.

So that you can relax while observing the comings and goings at a pair of the lower Susquehanna valley’s man-made impoundments, the Pennsylvania Game Commission has erected two viewing pavilions for public use on its lands…

The Haldeman Island observation pavilion is located on State Game Lands 290  just upstream from the Juniata River’s mouth on the Susquehanna at Clark’s Ferry in Dauphin County.
Haldeman Island Pavilion
It overlooks not only the island’s man-made shallow-water impoundments and neighboring grasslands, but the hacking tower used in the 1970s to reintroduce Bald Eagles from Saskatchewan to the lower Susquehanna.  Interpretive signs explain the conservation stories of habitats and the eagle reintroduction program.
Middle Creek W.M.A. Observation Pavilion
The observation pavilion at Middle Creek Wildlife Management Area is of similar construction to the one at Haldeman Island.  It is accessed from the parking pull-off along the tour road at its intersection with Chapel Road, just before the right turn and incline that leads to the “Stop 3” grassland overlook.
It too includes numerous interpretive signs to help visitors understand impoundment management.

During the next two weeks, the exodus of migrating shorebirds now staged and feeding upon Atlantic Horseshoe Crab eggs on Delaware Bay will commence.  During the evening of their departure from the bay, many of these birds cross portions of the Lower Susquehanna River Watershed, particularly east of the river.  Stormy weather and other climatic conditions may force some of them to seek a place to put down temporarily, so keeping a close eye on the new pothole-like impoundment at Middle Creek may be a prudent move.  After that, waders known as “post-breeding wanderers” can show up at any time.  Then, beginning as early as late June, shorebirds begin moving south on a migration that can provide us with viewing opportunities into September and beyond.  See you out there!

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Scenes from a Managed Grassland Ecosystem

Pretty pictures…

Veery
Photographing Neotropical migrants as they arrive to nest in our local forests can be frustrating under closed canopies and diffused light conditions.  We instead decided to focus our efforts and lenses on the grassland species at Middle Creek Wildlife Management Area where, earlier this week, several prescribed fire burns were wrapping up the spring treatments for 2026.
Warm-season grassland
Managed warm-season grassland habitat at Middle Creek Wildlife Management Area.
Tree Swallow
Already tending nests containing eggs and young, Tree Swallows are scattered around the refuge’s grasslands to welcome newly arriving migrants, and human visitors!
Grasshopper Sparrow
Middle Creek is probably the best place in the lower Susquehanna valley to see ground-nesting Grasshopper Sparrows.
Grasshopper Sparrow
To attract a mate and establish a defendable territory, the males are singing their buzzy, insect-like songs from atop roadside fence posts.
Grasshopper Sparrow
The songs persist as the male moves from perch to perch around a potential breeding site.
Grasshopper Sparrow and Tree Swallow
It’s a behavior that occasionally puts the newcomer Grasshopper Sparrow in conflict with a well-ensconced Tree Swallow guarding its nest box.
Eastern Bluebird
Eastern Bluebirds squeeze in among the Tree Swallows to find a vacant nest box within which they can raise their young.
Song Sparrow
Song Sparrows may be present year-round in grasslands with interspersed growth of early successional shrubs and briars, however the populations at a given location changes as birds migrate in and out of the area seasonally.  Those individuals observed nesting here in the spring and summer are not usually the same birds seen during the late fall and winter.
Savannah Sparrow
As a species, the Savannah Sparrow, like the Song Sparrow, may be represented in the grasslands throughout the year, though the individuals vary with the changing seasons. Unlike the Song Sparrow which nests in shrubs, the Savannah Sparrow nests on the ground among thick grasses.
American Goldfinch
Still munching on the seeds of last year’s wildflowers, American Goldfinches are pairing up around the grasslands waiting for thistle down and other fibers to be available for nest construction.  They will then build a small cup within the upper limbs of a small to medium-sized tree to shelter their eggs and nestlings.
Common Yellowthroat
The Common Yellowthroat, one of our Neotropical warblers, will reproduce in grasslands with scattered early successional thorny shrubs to afford a safe place to construct a nest. The males sing almost incessantly from the time they arrive in late April and early May until sometime in July, or even later.
Eastern Kingbird
Eastern Kingbirds are arriving from tropical wintering grounds to nest in grasslands and pastures throughout the lower Susquehanna region.  They are a tyrant flycatcher that will ambush insects from a perch atop a tree, shrub, or tuft of tall grass.
Northern Mockingbird
Northern Mockingbirds are considered a resident species, though there may be some southward movement during severe winters when foods such as berries become scarce. At Middle Creek, some of these evacuees have returned to nest along the interface zone between the grassland and early successional shrub habitats.
Horned Lark
Nesting Horned Larks apparently take advantage of the interface between the managed grasslands and nearly bare soils in spring-planted croplands at Middle Creek. They may be one of the few, possibly the only, species of bird life to take advantage of no-till farming for nesting on the ground.
Red-winged Blackbird
Red-winged Blackbirds not only construct nests in cattails and other marsh growth, but in dense grasses and shrubs in and near grasslands and pastures. The males are easily seen displaying their plumage as they sing from a small tree, shrub, or a cattail seed spike.
Female Red-winged Blackbird
Less frequently seen is the female Red-winged Blackbird.  She spends the majority of her time in the nest, but will periodically come out to join the ruckus when an intruder is being scolded into leaving the premises.
Eastern Meadowlark
Another member of the blackbird family is the Eastern Meadowlark.  It too is an energetic singer during the breeding season.  Meadowlarks build their nests on the ground, often in pastures of cool-season grasses where harvests prior to August are fatal to eggs and young.  Middle Creek’s managers delay harvests to allow the birds enough time to complete their reproduction cycle.
Bobolink
Another blackbird is the Bobolink, an obligate grassland specialist and a Neotropical migrant.  One of its few uses for trees and shrubs is as a place to burst into display and song, though it will also perform these rituals on the wing and among the grass.
Bobolink
A male Bobolink singing and displaying from a perch.
Bobolinks
As the males arrive, competition for suitable nesting sites among the grasses becomes intense, even before a female is anywhere in sight.
Bobolinks
We saw as many as five males at a time clustered into this one tuft of thorny twigs to take turns chattering and showing their wares to one another.
Bobolink
A territorial male Bobolink at Middle Creek Wildlife Management Area.  Delayed mowing allows cool-season grasslands to provide nesting sites for this species too.
Baltimore Oriole
Did you know the Baltimore Oriole is a blackbird?  Well, it is.
Baltimore Oriole
When surrounded by acres of grasslands for collecting insects, groves of mature shade trees including oaks, walnuts, sycamores, and elms provide excellent nesting sites for Baltimore Orioles.
Baltimore Orioles
Competition for these ideal sites can get quite animated.
Baltimore Oriole
Fights like this one between two second-year males can become vicious,…
Baltimore Orioles
…leaving combatants rolling on the ground in their fury,…
Baltimore Orioles
…at least until the more-experienced adult males who’ve been fighting over the place have had enough…
Baltimore Orioles
…and decide to send the clumsy, younger males packing.
Western Cattle Egrets
During our visit to the Middle Creek grasslands earlier this week, we were afforded an encounter with some unusual grassland birds, Western Cattle Egrets.  To the delight of birders who never got to enjoy the abundance of this species on the lower Susquehanna during the 1970s and early 1980s, these birds have been a popular attraction as they’ve lingered around the refuge for a couple of weeks now.
Western Cattle Egrets and Geese
It’s an unusual experience, watching Western Cattle Egrets feeding in a field of cultivated cool-season grasses alongside Snow Geese, though they certainly aren’t looking for the same thing.

We’ll have more on the Western Cattle Egrets and other interesting migrants at Middle Creek in an upcoming post.  Check back soon!

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Photo of the Day

Lesser Yellowlegs
Numbers and varieties of northbound Neotropical songbirds and shorebirds are presently reaching their peak in the Lower Susquehanna River Watershed.  Upon arrival, those species that breed locally will begin protecting a home range without delay.  These Lesser Yellowlegs on the other hand will ultimately defend nesting sites in boreal forests far to our north, but they can still become spectacularly aggressive toward one another while passing through.  During coming weeks, expect birds of reproductive age to demonstrate a similar demeanor, especially the males.  You won’t want to miss the handsome plumage, the songs, and the territorial behaviors of migratory birds in May.  It’s a big part of what makes them so worthy of our best efforts to appreciate and protect them.
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Photo of the Day

Red-banded Hairstreak
Not sure how we happened to spot this little gem in the backlit glare of the late-morning sunshine.  It’s a Red-banded Hairstreak perched at the end of an Eastern Red Cedar branch.  The blossoms and seeds surrounding it are suspended in some minute cobwebs that snagged them as they sailed downward from nearby trees.  These southeastern butterflies are regular spring and summer wanderers north of the Mason-Dixon line.  The gusty southwest winds earlier this week were apparently sufficient to help transport this particular one to the Conewago Creek (east) valley of Lancaster County.  The Red-banded Hairstreak is a member of the “groundstreak” group, its larvae feeding on decaying dead leaves.
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Common Dandelions Are as Good as Gold

American Goldfinches Feeding on Common Dandelion Seeds
Please tell us you’re not putting herbicides and other toxic chemicals on the dandelions and other antioxidant and anti-inflammatory plants in your lawn and garden,…
American Goldfinches Feeding on Common Dandelion Seeds
…because even if you don’t have sense enough to eat them, many native species of animals do.
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Photo of the Day

Luna Moth
Outside susquehannawildlife.net headquarters this morning, we were delighted to find this nocturnal Luna Moth (Actias luna), one of the “giant silkworm moths”, clinging to the side of one of our bee houses.  During hours of darkness, this male is on a mission of radar love, his feather-like antennae used to detect pheromones produced by ready-to-mate females.  Host plants for larval Luna Moths include deciduous trees such as willows, beeches, hickories, cherries, alders, and hazelnuts.  It just so happens that we’ve been growing several American Hazelnuts (Corylus americana) in the garden for the past two years.  We’re hoping they’ll help attract a mate for this colossal beauty.
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New Floodplain and Stream Restoration Projects 4U2C

The majority of floodplains in the Lower Susquehanna River Watershed are, to put it mildly, dysfunctional.  They are frequently disconnected from the lotic (flowing) streams and rivers that created them and are no longer capable of absorbing, purifying, and infiltrating high water during rain and snow-melt events.  They are an ongoing source of nutrient and sediment pollution that impairs both our local waterways and Chesapeake Bay.  For the plant and wildlife species that rely upon them for survival, their loss has been catastrophic.

Mill dams once impounded nearly every mile of low-gradient streams in the lower Susquehanna region.  During the century or more of their existence prior to the implementation of soil conservation practices during the 1930s, sediments consisting mostly of nutrient-loaded clay, silt, and sand eroded from sloped terrain in storm runoff and accumulated behind these dams, filling many to the brim with mud—six, eight, ten, sometimes twelve feet deep!  As the dams fail or are removed, the stream is left channelized, incising a path through a floodplain choked with these “legacy sediments”.

Legacy Sediments
That’s it, a fresh layer of topsoil oughta do it-  Landowners have become so accustomed to legacy sediment pollution and channelized creeks, they think it’s how a natural stream and floodplain ecosystem looks and operates.  They’ll even replace washed away legacy sediment with dirt, rocks, cinder blocks, old sidewalks, and other construction debris to “shore things up”.  It’s a delusional approach to managing a space that functions as a place to store, treat, and percolate precious water.
Legacy sediments not only displace flood waters into historically unimpacted lands, they clog the hyporheic zone, the area below and alongside the flowing stream where water is exchanged with the aquifer.  (United States Geological Survey image)
Legacy Sediment Layer
Restoration of creeks and floodplains impacted by legacy sediment pollution includes the removal of the layer of nutrient-loaded sand, silt, and clay deposited atop the historic stratum of wetland and stream substrates.  These lower layers are frequently gray in color and contain gravel from the former stream beds.  Within the organic matter contained in this historic layer, seeds of native wetland plants have rested dormant for more than one hundred years.  Some are still viable and will germinate upon liberation from the overlying legacy layer.
Legacy Sediments Removed from Swarr Run Floodplain
Stockpiles of legacy sediments and larger fill items await transport to upland sites for reuse following removal from the impaired floodplain during a stream restoration project completed during the past year on Swarr Run, a tributary of Little Conestoga Creek in Lancaster County, Pennsylvania.  This excavation, part of the project’s phase-two plan, was preceded in 2020 by similar construction completed as phase one on a segment located just upstream.
Swarr Run
Swarr Run has been returned to a meandering stream course in a floodplain cleared of nutrient-rich legacy sediments.  How are legacy sediments repurposed?  Those from previous projects in the lower Susquehanna valley have been used to create a community garden, as a top coating on athletic fields, as a safety backstop at a shooting range, and as topsoil on some of the croplands from whence they came all those years ago.
Restoring pool and riffle or meandering stream flow regimes also restores water exchange in the adjoining hyporheic zones.  (United States Geological Survey image)
Before and After Legacy Sediment Removal
Removing legacy sediment accumulations from the floodplains of impaired streams allows re-establishment of historic flow regimes and reconnection of the waterway to the nutrient-sequestering functions of fluvial wetlands.  In addition, flow into and from the water table is restored.
Swarr Run Stream and Floodplain Restoration
Question: Do you know why nearby businesses have ATMs?  Answer: Because there are no longer any banks on this segment of Swarr Run.

For a closer look at the Swarr Run renewal, including early map and aerial photograph views of the site, take a peek at this synopsis illustrating phase one of the project as presented to the North American Association of Wetland Managers by Justin Spangler of LandStudies, designers of the restoration.  While perusing the material, be sure to review the significant reductions in nutrient and sediment loads discharged from these sites following the restoration work.

Stormwater Discharge
Floodplain restorations that include legacy sediment removal are often designed to reduce the impact of stormwater from sheet runoff, piped discharges, or conveyances such as eroded and excavated ditches like this one.  Projects that restore floodplain functions including storing, filtering, and percolating runoff effectively can sometimes help municipalities and property owners meet regulatory stormwater requirements, including those under the Environmental Protection Agency’s MS4 (Municipal Separate Storm Sewer System) program.
Little Conestoga Stream and Floodplain Restoration
This floodplain restoration was completed during the past year along a segment of Little Conestoga Creek in Lancaster, Pennsylvania.  Here the stream receives a heavy dose of stormwater runoff from shopping malls and other commercial properties with acres upon acres of paved parking space.  Because they lack connection to any retention or detention systems, storm drains pipe runoff directly from the pavement into the creek from many of these properties.
Little Conestoga Reconnected to Floodplain
Legacy sediment removal eliminates the steep banks along the channelized creek. Braided stream courses were added to again connect the Little Conestoga to its historic floodplain and a complex of wetlands to help store, treat, and infiltrate stormwater.
Removing legacy sediments brings an end to their practice of forcing detrimental high waters out to roam adjacent neighborhoods, putting floods back in the floodplain where they belong.
Conoy Creek Stream and Floodplain Restoration
Completed last year in conjunction with replacement of an aging sanitary sewer interceptor (buried to the right), this floodplain restoration removed legacy sediments and returned Conoy Creek in Lancaster County, Pennsylvania, to a natural, braided stream course.
Conoy Creek Stream and Floodplain Restoration
As part of the project, municipal storm drain discharges were withdrawn from the edge of the channelized stream to now flow runoff into the floodplain wetlands for storage, thermal moderation, nutrient sequestering, and infiltration.  The braided stream design connects the waterway to these wetlands and helps restore the hyporheic functions between the Conoy and its underlying New Oxford Formation sandstone aquifer.  This project helped the local municipality meet its MS4 (Municipal Separate Storm Sewer System) requirements.
Cocalico Creek Stream and Floodplain Restoration
Following restoration, a braided stream design reconnects Cocalico Creek in Lancaster County, Pennsylvania, to its floodplain wetlands along this 3,867-foot segment near its headwaters.  As part of the construction process, twenty-five acres of invasive growth was treated prior to the planting of 12.7 acres of native riparian buffer species.  According to the Pennsylvania Department of Environmental Protection’s (DEP) project summary, annual pollutant load reductions resulting from this restoration are calculated to be 862,980 pounds of Total Suspended Sediments/year, 1,641 pounds of Total Nitrogen/year, and 426 pounds of Total Phosphorus/year.
Cocalico Creek Stream and Floodplain Restoration
The stream and floodplain restoration on Cocalico Creek is beginning its fifth year since completion.  It recreates marshlands that purify the stream’s waters while providing prime habitat for native plants and animals.  See the LandStudies project summary here.
Hammer Creek Stream and Floodplain Restoration
Hammer time-  Now under construction: after years of planning and preparations, a  floodplain and stream restoration on Hammer Creek near Buffalo Springs in Lebanon County, Pennsylvania, returns this low-gradient segment to a meandering flow regime.  Instead of a ditch between fields, it’ll once again be a creek connected to a nutrient-reducing wetland buffer.

Have an impaired stream and a floodplain full of legacy sediments on your land or in your neighborhood?  Consider encouraging your municipality, volunteer watershed group, or county conservation district to investigate the possibilities of planning and installing one of these projects.  They’re a great enhancement for recreational fisheries, a private refugium, or a community-owned passive park system.  Funding assistance may be available, particularly when regulatory or conservation goals can be met by completing restoration.

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Preventing Roof Water from Becoming Storm Runoff

Clean rainwater flowing from the roofs of our homes and other buildings is a precious resource that is more often than not directed as quickly as possible into streets and storm drains to become contaminated runoff capable of polluting streams and aggravating flooding conditions.  The prudent property steward will manage rainfall as the treasured commodity that it is—retaining on site as much of it as possible.

Whether you happen to be obtaining your domestic water from a community distribution system or from a private well, infiltrating the rain that falls on your roof directly into the soil is a good way to make sure it helps recharge the groundwater stored in the aquifer—banking it for future use.

Better yet, rain barrels provide a means of intercepting, storing, and dispensing a share of the precipitation from your downspouts before it is discharged into the ground.  Water from rain barrels can be drained to hydrate garden plants, rinse the patio, wash the dog, or, in the event of an emergency, fill the need for non-potable uses that include bathing and flushing toilets.  For potable applications such as cooking, drinking, and brushing teeth, roof water must first be filtered and disinfected.

Rain barrel layout for a 1,200-square-foot house.
Rain barrels collect and save clean roof water for later use.  For every one inch of precipitation, the roof on a house or other building with a footprint of just 1,200 square feet sheds enough to fill about fourteen 55-gallon drums.  Live in a home supplied by a well?  That’s over 700 gallons of soft water available as you need it, such as during a power outage when the pump won’t operate.

Here at susquehannawildlife.net headquarters, our goal is “no net runoff” from our little urban parcel.  We use three rain barrels to catch discharge from the spouting system, then direct the overflow into three different management configurations.

RAIN GARDEN

Commercial Rain Barrel
Precipitation from the downspout is captured in this commercially produced rain barrel.  The overflow is directed into the black corrugated pipe…
Rain Garden Receiving Overflow from Rain Barrel
…and spilled into the gravel bed in the rain garden to both water the plants and infiltrate into the ground to recharge our local aquifer.
Gravel Beds in Rain Garden
The gravel beds diffuse energy produced not only by water rushing from the barrel’s overflow, but from sheet runoff entering the garden from the driveway and neighboring street.

STOCK TANK PLANTER

Planter Receiving Overflow from Rain Barrel
This home-brew rain barrel was fabricated from a 55-gallon drum originally used to ship and store car wash soap.  We scrubbed it out, then plumbed it up with the overflow feeding a 100-gallon stock tank fashioned into a planter.  The drain from the planter sometimes discharges a trickle of water into a porous area of the pavement where it soon percolates into the ground.  In this “container rain garden”, we grow wildflowers, sedges, rushes, and warm-season grasses.

THE GARDEN POND/POOLS

Pond/Pool Receiving Overflow from Rain Barrel
Here’s another rain barrel made from a soap drum.  This one discharges its overflow into the upper pool of our garden pond.
Pond/Pool Receiving Overflow from Rain Barrel
Upon topping off the barrel, clean roof water spills into the corrugated pipe and tumbles into the upper pool.  Outflow from the upper pool cascades through the the riffles/falls…
Overflow from Upper Pool Fills Lower Pool (Sump)
…into the lower pool (bottom right).  The lower pool consists of a 100-gallon stock tank sunk below grade level and surrounded by rock.  Throughout the summer, a pump located in this “sump” circulates water to a spring-like feature in the upper pool.  During a downpour, the lower pool will overflow into the encircling boulders, the level often rising half a foot or more above the top rim of the stock tank flooding the cap stones before receding as the excess water slowly infiltrates down through the gravelly soils.  It’s a self-automated, hassle-free water change that helps keep our pools and their inhabitants healthy.
Rain Barrel Overflow Management
Our garden pond stormwater management system keeps the pools topped off and the aquatic ecosystem thriving.

Why not give roof water management a try on your property?  It’s a great project for exercising your ingenuity and creativity while doing something truly beneficial for the watershed within which you reside.  Best of all, it’s really not that expensive to get started.

Container Rain Garden
A virtuous goal in a wasteful world.
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The Water Cycle

The dynamics of water’s storage and movement on earth, as well as its transitions through the primary states of matter—gas, liquid, and solid—are known as the water cycle.  Understanding how life-supporting water progresses through the global biosphere can provide each of us with a greater appreciation of how fragile a resource clean water is in the presence of 8.3 billion wasteful and polluting humans.

This graphic created by the United States Geological Survey illustrates many of the components of the water cycle’s complex processes.  Have a look…

The Water Cycle
The Water Cycle.  Click the image for an enlarged view.  (United States Geological Survey image)

For a PDF version which includes a more detailed description along the bottom margin, click here.  We like it so much, we’ve added it to this webpage’s sidebar for future reference.

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Managing a Grassland Ecosystem

If you’ve visited Middle Creek Wildlife Management Area anytime during the past month, you may have noticed quite a bit of activity around the large pole-mounted nest boxes placed out in the open fields.

American Kestrels at nest box
American Kestrels, a male and female, at a nest box at Middle Creek Wildlife Management Area.
Kestrels competing for nesting sites and territory.
Within the past week, we noticed that kestrels are still competing for nesting sites and territory, driving away unwanted trespassers.  A pair of kestrels seemed to be occupying each of the four box sites we observed.  That’s good news, but the presence of these man-made nest cavities is in no way wholly responsible for this positive response from these declining birds.  It’s a matter of habitat, much needed grassland habitat.
Cool Season Grasses
Cool-season grasses including fescue (Lolium species) and non-native Orchard Grass (Dactylis glomerata) mature by late spring.  If left standing, they continue to provide indispensable habitat for grassland wildlife through the summer.  Mowing early and often for hay harvest has rendered most cool-season meadows death traps for nesting birds.  By delaying cuttings until at least early August, ground-nesting birds are given adequate time to fledge their young and get the juvenile birds strong enough to fly away from a set of spinning blades.
Grasshopper Sparrow in Timothy
A male Grasshopper Sparrow sings to demarcate its nesting territory in a stand of Timothy, an introduced species cultivated for harvest as hay.  An insectivore during the breeding season, he and his mate will attempt to raise their brood exclusively within the cover of these cool-season grasses.
Eastern Meadowlark
Eastern Meadowlarks arrive in cool-season grasslands by late-winter to begin their breeding cycle which typically extends into the hot summer days of July.
Orchard Grass with Black-eyed Susans
Prior to being mowed, Orchard Grass provides the short, dense cover meadowlarks and other ground-nesting grassland birds need to successfully reproduce.  Growing a cool season grassland can be as easy as delaying the mowing of a pasture, field, or oversize lawn until August, then have a farmer friend come and take off a cutting or two of hay or straw to prevent woody plants from becoming established.
Warm-season Grasses
More durable stands of native warm-season grasses including Big Bluestem, Indiangrass, Switchgrass, and Little Bluestem thrive in the summer heat and provide wildlife habitat throughout the year.  These perennial “prairie grasses”, fed by root systems five to eight feet deep, are especially drought tolerant .  From these entrenched anchors, the plants would quickly bounce back after the once great herds of hungry bison had grazed the landscape bare of surface vegetation before moving on.  This adaptation also assured “prairie grass” regeneration following naturally occurring seasonal fires, events mimicked in eastern North America by its pre-Columbian human residents.  They used recurrent fire to perpetuate early successional habitat for wildlife propagation, foraging, and agriculture.  Today in the lower Susquehanna watershed, establishing warm-season grassland meadows requires soil prep and seeding to get things going again.
Precribed Burn
To prevent succession, warm-season grassland parcels are most commonly maintained using applications of prescribed fire every 3 to 5 years.  Among their benefits, these burns invigorate native vegetation while inhibiting the invasive tendencies of many non-native plants.  Well-planned periodic fire can significantly reduce fuel accumulations, particularly in tinderbox woodland tracts managed as fire-free zones for the past century or more.  Many forest trees including oaks rely on sporadic fire events for regeneration.

LEARN HOW LAND MANAGERS UTILIZE PRESCRIBED FIRE

This coming Saturday, April 18, 2026, beginning at 10 A.M. (rain date April 25), the Pennsylvania Game Commission is hosting a “Prescribed Fire Festival” at Middle Creek Wildlife Management Area.  Be certain to come out to the visitor’s center at 100 Museum Road, Stevens, PA, for this event.  Land managers will be there to answer questions and to explain the planning and preparations involved in overseeing a prescribed burn.  There will be guided walks of habitats preserved using fire of varying intensities.  You’ll see the equipment and protective clothing used by certified personnel to administer a live prescribed fire burn right before your eyes.  Then you can have lunch—food trucks will be available on site.

Prescribed Fire Demonstration
Visitors witness a prescribed fire demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area in 2025.

After the burn demonstration, why not go for a walk or drive around the refuge.  You can take note of how grassland and early successional plant communities are responding to previous doses of prescribed fire…

Wingstem
Greening up a week or two after the burn, Wingstem is blooming by June in areas treated using prescribed fire earlier in the spring.
Joe-Pye-Weed
Another scene from June: Four-foot-tall Joe-Pye-Weed amidst lush growth of goldenrod in early successional habitat where a prescribed burn eliminated accumulating wildfire fuel and turned back the growth of invasive plant species in March.

And how the grassland animals respond as well…

Ring-necked Pheasants
Ring-necked Pheasants in early successional habitat maintained by the periodic application of prescribed fire.
Eastern Cottontail
Eastern Cottontails prosper in the mosaic of warm-season grasses and early successional thickets on lands sustained using prescribed fire.  Rabbits are herbivores, primary consumers eating mostly legumes and other plants, the producers that through the process of photosynthesis convert the energy of the the sun into food energy.
Northern Short-tailed Shrew
Other small vegetation-eating rodents including mice and voles thrive in managed grasslands.  Similar in appearance are the shrews.  Though seldom noticed, Northern Short-tailed Shrews spend day and night foraging for food, even in the shallow waters of wet meadows and thickets.  Unlike the aforementioned herbivorous rodents, shrews are insectivores, secondary consumers feeding mostly on primary consumers including a variety of insects and other arthropods.
Masked Shrew
Some years ago, we found this tiny Masked Shrew (Sorex cinereus) in a grassland area being preserved using prescribed fire.  Like other shrews, Masked Shrews are secretive, but always on the go.  They feed constantly to fuel their vast energy requirements, sometimes consuming three times their body weight in a single day.  But their voracious appetite can get them into trouble, causing these incessant eaters to encounter numerous potentially infective parasites during their non-stop foraging missions.
Female American Kestrel
Patrolling the grasslands is the female American Kestrel, a secondary consumer.  She’s on the lookout for primary consumers including large insects like grasshoppers or crickets.  But perhaps more likely is a small rodent whose less-than-ideal vigor may cause it to slip up, creating an easy target.  If she selects a careless shrew as her prey, she may be assuming the role of a tertiary consumer, eating a secondary consumer (the shrew) that fed on insects (the primary consumers) that derived their energy from photosynthesized plant matter.
American Barn Owl
The strictly nocturnal American Barn Owl (Tyto furcata), another secondary and sometimes tertiary consumer, takes the night shift, hunting unwary voles, mice, and shrews, often by sensing the sounds they make among runways in the grass.  As a native predator in its favored habitat, the owl’s selection of each victim actually helps to keep the prey species’ population healthy, eliminating the weak and vulnerable to provide a qualitative service to the surviving wildlife of the grasslands.  While we may not think of the barn owl as a direct consumer of insects, its positive influence on insectivorous shrew populations makes it an important functionary in maintaining balance in the ecosystems it calls home.
Male American Kestrel
As food becomes increasing plentiful in the grasslands, a female kestrel will remain mostly out of sight, performing the majority of the egg incubation duties while her colorful mate stands guard nearby.
Male American Kestrel
The male not only keeps watch, but also continues the hunt for insects, small mammals, and other prey to feed not only the newborn nestlings, but also his mate while she tends the nest.  As the young grow and no longer need brooding to stay warm, the female will join the male in a joint effort to snatch up enough food to keep their three to seven offspring nourished.  Like other raptors, populations of these predators are abruptly regulated in the nest.  The first hatched of these falcon’s young will receive the most food, giving them, particularly the oldest individual, the best chances of survival.  The later-hatched and thus smaller offspring may have trouble competing for the available provisions brought to the nest.  If food is plentiful, there may be enough for all of the birds to grow and survive.  If food is scarce, only the oldest (which also happen to be the biggest, strongest, and most aggressive) baby falcon(s) will live to fledge and leave the nest.  If hunting becomes really poor, the adults will sustain themselves at the expense of their young.

The fate of an avian predator such as a kestrel lies at the mercy of the fate of its quarry.  Because, you see, the sun’s energy, after being converted to chemical energy by photosynthesizing plants, flows upward through the trophic levels of the food chain—herbivores (primary consumers) such as rodents and insects to carnivores (secondary and tertiary consumers) including kestrels.  Grasslands, when abundant and diverse, are correspondingly abundant and diverse with small mammals and insects and will therefore support thriving populations of American Kestrels and other predators.  These secondary and sometimes tertiary consumers fulfill a role in cultivating healthier populations of their prey—the primary and secondary consumers in the food web—as a balanced component of a flourishing grassland ecosystem.  Sparse and fragmented grasslands, on the other hand, beget negligible small mammal and insect populations, are stricken with broken food webs, and champion few if any American Kestrels or other predators.  If the land it occupies is neat, tidy, manicured, exploited, or sprayed sterile and dead, the energy flow cycle of the ecosystem is dead as well.  There’s nothing animal introductions, reintroductions, rescues, culling, stocking, or harvesting can do about it, because in the end, it’s all about the habitat.

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Migrating Waterfowl on Lotic Fresh Waters

Lotic vs. Lentic Freshwater Ecosystems
Some comparative attributes of unspoiled lotic vs. lentic freshwater ecosystems.  Low-gradient (slow-moving) lotic waters often create, and remain connected to, accompanying riverine wetlands (a lentic freshwater ecosystem).  These swamps, marshes, and ditches absorb, purify, and infiltrate flood waters while supporting a diverse number of plant and animal species.

We frequently perceive all waterfowl migration to be synchronized with the conspicuous movements of familiar species like Snow Geese, Tundra Swans, and Canada Geese—big flights coming south in October and November, then a return to the north in late February and March.  And we’re all quite aware of the occurrence of large gatherings of some of these migrants while they make stopovers on some of our largest lentic (still) waters—the man-made lakes and reservoirs created by damming local streams.  But did you know that there are populations of colorful waterfowl with dynamic migrations that extend throughout the winter and early spring with movements that are often continuous.  Under favorable conditions, these birds favor the lotic (flowing) waters of the river and its larger tributaries as they transit the lower Susquehanna valley.  That’s because unpolluted lotic freshwater ecosystems support a greater diversity of plants and animals than lentic waters, and therefore offer more opportunities for hungry migrating waterfowl to find food.  Let’s have a look at some of the species that visit the river during their seasonal journeys…

Ice on the Susquehanna
While the urge to head south in the autumn is largely stimulated by the shortening of the photoperiod, it is the presence of ice, particularly on glacial lakes throughout the lands to the north of the lower Susquehanna River basin, that pushes many diving ducks to finally make their way south toward the guarantee of open-water feeding areas along the coast.  This movement may occur at anytime between November and late February or, as we have seen during some of the mild winters of recent decades, it may scarcely be noticed at all.
Common Mergansers
Common Mergansers often lead they way when it comes to migratory diving ducks.  They regularly move south in conspicuous numbers by late November and December and are regularly pushing north as soon as the ice begins to melt.  During a typical year, it is not unusual for some populations of these large diving birds to remain north of us during the winter.  Then, in the days after a sudden rush of frigid polar air, an appreciable increase in ice cover will force a mid-winter movement of birds down the Susquehanna.
Heat Flux Sources Impacting Temperature in Lotic Fresh Waters
Temperatures in lotic fresh waters vary over the length of the stream or river.  They are largely determined by the collective impact of the numerous sources of heat flux depicted in this graphic.  (Environmental Protection Agency image)
Buffleheads
Buffleheads begin passing through the lower Susquehanna region in Novemeber on their way to coastal saltwater bays for the winter.  Lingering populations feed by diving in the river’s pools and riffles for benthic invertebrates including snails and insect larvae.  Lesser quantities of aquatic plant matter supplement their diet.
Common Goldeneye
Many Common Goldeneyes will remain on shallow, ice-free waters of the northern lakes and rivers sculpted by the most recent glacial event, but only until they are forced south into and through the lower Susquehanna valley by the encroachment of freezing conditions.  On the river, they are among the dozen or so species of diving ducks we see visiting or passing through during the typical late fall and early river.

 

Geomorphological Zonation of a Stream or River
During their visits to the lotic (also known as riverine) fresh waters of the Susquehanna and its largest tributaries, benthic-feeding waterfowl make short dives to take advantage of the plants, small fish, invertebrates, and other food sources inhabiting the stream bottom in the riffles and pools of the free-flowing waterway.  Substrates, listed here by size (in descending order), along with other parameters influenced by this flow regime zonation determine the variety and abundance of the forage available to migrating waterfowl and other consumers.  Ice or high water and poor visibility due to flooding can render the riffles and pools of the channel unusable for feeding.  The birds must then choose to either linger and rest without feeding or leave the lotic freshwater habitat to seek sustenance.  During a flood, this may require relocation to a nearby lentic (still) body of fresh water such as a lake or reservoir.  The presence of ice will almost invariably force the birds to fly on to the Atlantic Coastal Plain and the tidal waters of its bays and estuaries.
Hooded Mergansers
Hooded Mergansers are one of the few species of diving ducks likely to utilize flooded shoreline timber and riverine (fluvial) wetlands as refuge from high water on Susquehanna.
Pied-billed Grebe and Canvasbacks
A Pied-billed Grebe and a pair of Canvasbacks on an ice-free stretch of the lower Susquehanna in mid-winter feed and loaf in a riffle-flanked pool where a large mat of American Eelgrass, a submerged aquatic plant also known as Tapegrass or Wild Celery, grows during the summer.  The vast mosaic of riffles and pools in a river this size offers tremendous opportunities for a diverse array of aquatic species to find their niche wherein they can survive and flourish.
Bufflehead
The presence of ice forces Buffleheads and other diving ducks to gather in turbulent open water, often below a riffle or dam.  Another alternative is to continue on toward the salty bays and estuaries of the coast.  High water may push these birds into the shallows among the flooded woods to feed, but they seldom utilize heavily forested riparian wetlands as a refuge due to their need for a running start to get airborne.

 

Riffle and Pool Characteristics of High Gradient (A) and Low Gradient (B) Streams.  This graphic illustrates the change in deposition characteristics of a stream or river as its gradient decreases.  A high-gradient stream (A) has a rapid velocity, often forms falls, and tends to carry away a high volume of all but the largest of particles of potential substrates as they erode from the surrounding landscape.  On a low-gradient stream, the loss in water velocity reduces the water column’s ability to transport even the smallest of substrate particles.  Deposition of this gravel, sand, silt, and clay forms lateral bars that over time create the familiar meandering path of a naturally flowing lowland stream.  (National Park Service image)
Benthic Life in Lotic Freshwaters
Benthic substrates in lotic freshwater pools and riffles support an abundance of life forms ranging from colorful diatoms on rocks and cobble, to invertebrates including snails and insect larvae, to fishes like this young Channel Catfish.  Free of accumulations of sediment, this river bottom not only provides habitat for a healthy fishery, it facilitates the bidirectional exchange of water between the Susquehanna and its underlying aquifer.
Quillback
On the lower Susquehanna, populations of young Quillback suckers are found almost exclusively in clear, high-gradient pools.
Harlequin Duck
The Harlequin Duck winters along the rocky shores and man-made jetties of the Atlantic coast.  In summer, they nest on fast-moving, headwater streams well to our north.  Very rare on the Susquehanna, this is the first of two individuals found during March and April of 2025.  It was observed feeding in the swift waters of the high-gradient riffles and pools where the river cuts through Blue Mountain north of Harrisburg.  During previous weeks, Harlequin Ducks were being seen along the coast as far south as the mouth of the Chesapeake at Cape Charles, Virginia.  It’s very possible that some of these birds traveled north through the bay area and up the Susquehanna on their way north.

 

Fluvial Geomorphology of a Stream.  Many of the Susquehanna’s tributaries pass through each of these three erosional zones.  Along the way, they carry out the process of breaking down the mountains formed by the Allegheny orogeny, the collision of North America and Africa that created the supercontinent Pangea about 325 to 260 million years ago (during portions of both the Carboniferous and Permian periods).  Today’s main stem of the lower Susquehanna passes through a transfer zone (Zone 2), carrying eroded materials to a depositional  zone (Zone 3) located within the ancient Susquehanna canyon stretching from Havre de Grace, Maryland, to Norfolk Canyon on the edge of the continental shelf.  Within this zone, more than a 10,000-year accumulation of post-glacial sediments lies submerged by the rising waters of the Atlantic Ocean and Chesapeake Bay.  Although the present-day lower Susquehanna is largely a transfer zone, some deposition occurs along low-gradient segments of the river, particularly where its course parallels the watershed’s ridges both above and below the high-gradient rapids where its path has eroded passage through the highlands.  (National Park Service image)
Although the present-day lower Susquehanna is largely a transfer zone, some deposition occurs along low-gradient segments of the river, particularly where its course parallels the watershed’s ridges both above and below the high-gradient rapids where its path continues to erode passage through the bedrock.  On this 1908 map of the Susquehanna at Conewago Falls, alluvial terraces of gravel, sand, silt, and clay can readily been seen as pale areas nearly lacking brown contour lines along the shorelines and islands of the river.  Deposits within most of these terraces date back to the melt period following the most recent glacial event and beyond.  The delta shown at the mouth of Conewago Creek (west) includes massive volumes of material deposited by both the creek and the river.  This delta is currently known as Brunner Island, much of it developed as the site of a coal/gas-fired electric generating station.  Terrace deposits along the Susquehanna’s shorelines created extensive perched marshes and swamps (wooded marshes) fed by rains, high river water, small streams, and springs, the latter often seeping from the base of the rocky escarpments carved by the ancient Susquehanna and defining the present-day inland border of the floodplain.  We call these sites “Alluvial Terrace Wetlands”.  Few of these critical components of river morphology survive.  Those not drained for farmland were obliterated by urbanization and canal, railroad, and highway construction.  (United States Geological Survey base image: Middletown, PA, quadrangle, 1908)
Water Willow
Water Willow is a familiar emergent plant that colonizes lateral bars and other alluvial deposits in low-gradient segments of the Susquehanna.
Water Willow Roots
The fine roots of Water Willow collect sediment and absorb nutrients while creating dense cover for young fish and numerous species of invertebrates including the Virginian River Horn Snails seen here.

Prior to the nineteenth century, the low-gradient flow regime of the river both above and below the riffles at Chiques/Chickies Rock (lower right on map) created prime wildlife habitat.  The natural accumulations of nutrients and substrates carried into and through the lotic waterway’s pools and riffles were cycled into an ideal growing medium for extensive mats of American Eelgrass and other aquatic plants.  This underwater forest hosted a seemingly endless abundance of invertebrates and fishes (both resident and migratory)—supporting a variety of consumer species including various populations of humans.  But soon after the mass clearing of much of the watershed’s land for farming and lumber, the mill ponds created by dams constructed on streams to power saw and grain mills became brimful with sediments eroded from the unprotected ground.  During storm events, torrents of these sediments then flowed full bore toward the Susquehanna, and began accumulating in the low-gradient segments of the river.

Legacy Sediments
Sediments left behind after the removal of mill dams are known as legacy sediments. They disconnect the stream from its historic floodplain and riverine (fluvial) wetlands, thus intensifying the impact of high water in the surrounding landscape.  As these nutrient-charged deposits wash away, they become a source of pollution in the waters of the Susquehanna and Chesapeake.
American Eelgrass
A mat of American Eelgrass growing in the flowing waters of the Susquehanna below Conewago Falls.  Eelgrass and other submerged aquatic plants provide essential habitat for a wide variety of small fish and invertebrates while also consuming nutrients deposited in the cobble, gravel, and sand substrate of the river’s pools.  Excess quantities of smaller particles of silt and clay can clog the substrate and thus inhibit the hyporheic exchange of water between the stream channel and the underlying aquifer, often diminishing the biomass and diversity of organisms inhabiting this benthic habitat.  Buried in these life-choking sediments, the river bottom becomes inhospitable to growth of submerged aquatics including eelgrass.
Susquehanna at Marietta
This low-gradient stretch of the Susquehanna at Marietta flows parallel to the Chickies Quartzite “Hellam Hills” before making a sharp right turn to punch through the ridge as a series of rapids at Chiques Rock.  Formerly a fully functional lotic ecosystem and a paradise for migrating waterfowl, this river segment is now impaired by accumulations of nutrient-laden sediments from agricultural and urban runoff.
Conewago Falls Flood Waters
Nutrient and sediment-loaded flood waters roar across the diabase boulders at the York Haven Dam and Conewago Falls, a high-gradient segment of the Susquehanna.
Flood Waters at Haldeman Riffles
They continue past Brunner Island (left power plant stacks) and through Haldeman Riffles and the Shocks Mills Railroad Bridge…
Flooding on the Marietta Broads
…into the stretch of river known as the “Marietta broads” along the base of the Chickies Quartzite “Hellam Hills”.  The low stream gradient here produces a slower current and increased deposition of sediments.
Susquehanna Flooding at Chiques Rock
As the flood surges through the riffle and pool complex at Chiques Rock, the high stream gradient maintains a velocity in the water column sufficient to keep additional sediments in suspension until they reach the low-gradient river segment just downstream at Washington Boro, site of a naturally occurring lateral bar area known as the Conejohela Flats.  These bars now lie within the man-made depositional zone known as “Lake Clarke”.  Created nearly a century ago by construction of the Safe Harbor Dam, this impoundment is accumulating astounding volumes of nutrient-loaded sediments that continue to encapsulate the flats within a stream-impairing delta.
Redheads, Canvasbacks, and a Horned Grebe
Anytime from November to April on the lower Susquehanna, a group of Redheads, Canvasbacks (3 birds to right of the middle of the picture), and a Horned Grebe (lower left) is a welcome sight in a riverine pool known to have a summertime growth of American Eelgrass.  Noted Dr. Herbert Beck in 1924 when describing the Canvasback, “Like all ducks, …, it stops to feed within the county (Lancaster) less frequently than formerly, principally because the vast beds of wild celery which existed earlier on broads of the Susquehanna, as at Marietta and Washington Borough, have now been almost entirely wiped out by sedimentation of culm.  Prior to 1875 the four or five square miles of quiet water off Marietta were often as abundantly spread with wild fowl as the Susquehanna Flats are now.  Sometimes there were as many as 500,000 ducks of various kinds on the Marietta broad at one time.”
Aythya genus ducks.
Today, seeing just dozens of Aythya genus ducks (Redheads, Canvasbacks, scaup) on the lower Susquehanna is a notable event.  If they happen to be forced down by inclement weather while migrating through, you might get lucky enough to see several hundred.
Aythya Genus Ducks
While the recovery of eelgrass/wild celery beds on the Susquehanna is trivial in scale and offers little support for numbers of waterfowl to return to historic levels, restorations on the upper Chesapeake in the vicinity of the Susquehanna Flats between Havre de Grace and Aberdeen Proving Grounds may have helped refuel a gathering of mostly Aythya genus ducks during the final days of February.  This mass of ducks, many of which were forced south from the frozen Great Lakes during the previous weeks (some by way of the ice-choked Susquehanna) were apparently making an abrupt turn to make their way back north.  Their stay was brief, but estimates by local birders put their numbers as high as one half million.  The vast majority of the concentration consisted of Aythya species: Redheads, Canvasbacks, Ring-necked Ducks, and both Lesser and Greater Scaup.  It probably included a mix of birds including both northbound migrants from further down the coast and the aforementioned refugees that had just arrived to pay a quick visit while escaping the late-season ice before turning around.
Lesser Scaup
During the past two centuries, as food supplies in the Susquehanna grew increasingly compromised for benthic feeders like these Lesser Scaup and other diving ducks, a change in distribution was necessary for survival.
Lesser Scaup in flight.
As individual species, Lesser Scaup and other waterfowl that fail to adapt to natural or man-made changes in their habitats and food supplies may see their overall global numbers falter.

Despite being located in the transfer zone, the lower Susquehanna has become a significant depositional zone along much of its length, mostly courtesy of the placement of sediment-trapping man-made dams.

Following construction of the mill dams and ponds on nearly every mile of the lower Susquehanna’s low-gradient tributary streams, enterprising parties moved on to the river.  The first significant spans were constructed using wide timber cribs filled with large rock.  They were placed to create water deep enough to allow canal boats to cross the Susquehanna at both Clark’s Ferry at the mouth of the Juniata River in Dauphin County and at Columbia/Wrightsville.  These dams also diverted water into the newly excavated canals—the Pennsylvania Eastern Division Canal (completed in 1833) which followed the river’s east shore from Clark’s Ferry to Columbia, and the Susquehanna and Tidewater Canal (completed in 1840) along the west shore from Wrightsville to Havre de Grace, Maryland.  Placement of these sediment-trapping man-made dams began a process of converting vast mileage of the lower Susquehanna from a transfer zone into a deposition zone.  In addition, layout of the canals and locks followed the contours along the base of the riverside ridges, seriously altering most of the alluvial terrace wetlands that the river had created as a feature of its floodplain during the post-glacial period.

Construction of the canal dams was just the beginning.  During the twentieth century, more massive dams would be added to the main stem of the river for hydroelectric energy production at York Haven, Safe Harbor, Holtwood, and Conowingo.  Upon their completion, the days of unassisted anadromous fish migrations were over.  On both the river and its tributaries, smaller dams including dangerous low-head dams maintain water levels for boating and recreation.  They too create current-diminishing, pseudo-lentic waters that blanket the lotic riffle and pool substrates with polluted sediments.

MAN-MADE DAMS TURN LOTIC WATERS INTO UNFLUSHED TOILETS

Sediment Deposition Behind Lower Susquehanna Dams
The construction of dams on the lower Susquehanna has converted vast mileage of the river from a lotic freshwater system into a series of man-made lentic freshwater reservoirs.  These areas have lost their function as a lotic transfer zone and are now a sort of dysfunctional series of depositional zones collecting vast volumes of sediment containing nutrients and other pollutants.  Within each impoundment, the reduced velocity of the river causes it to drop suspended sand first, then the finer particles of silt and clay closer to the dam.  The flow regime of riffles and pools is lost and the hyporheic zone that exchanges water between the river and the underlying aquifer is clogged.  These impaired segments of river become ripe for eutrophication: algal blooms followed by die offs that can lead to a fatal reduction of dissolved oxygen in the water column.
Gadwall
Deposits of lateral bars of sediment in low-gradient segments of the Susquehanna can create shallow water feeding habitat for puddle/dabbling ducks like these Gadwall.  Where sediment pollution is severe, benthic foods in these areas often consist mostly of invertebrates and plant matter deposited by the current, the buried substrates devoid of a functioning ecosystem and the waters subject to eutrophication.
Common Goldeneyes
Common Goldeneyes on a patch of open water on an otherwise ice-covered “Lake Clarke”, the impoundment created by Safe Harbor Dam.  While they may find this spot advantageous for loafing, the food supply over the sediment-buried substrate will be limited.

Dredging of sections of the lower Susquehanna for spilled, discarded, and washed-out anthracite coal sediment went on for nearly 100 years and was a particularly active enterprise in the Harrisburg area and in Lake Clarke until 1973.  The recurrent substrate disturbances that accompanied waste coal recovery in these segments of the river repetitively damaged habitat for benthic life and may have been the catastrophic factor leading to the extirpation of two species of freshwater mussels: the Eastern Lampmussel (Lampsilis radiata) and the Dwarf Wedgemussel (Alasmidonta heterodon).

By the end of the twentieth century, accumulations of polluted sediments behind lower Susquehanna dams were nearing capacity.  There is no working plan to attenuate the massive release of these pollutants that may be triggered by a catastrophic flood.  The effort to reduce nutrient and sediment runoff remains the focus so that new loading is kept to a minimum and won’t add to the capacity problems at the dams or continue downriver to the Chesapeake at full strength when the dams are full.  Alleviating the sediment aggregation problem within the river’s impoundments is a tall order and a dilemma not easily solved.  (United States Geological Survey image)
Common Mergansers
Common Mergansers will feed where benthic substrate supports the small fish and invertebrates they prefer. They will, however, gather in extraordinary numbers on the “lakes” created by riverine dams.  Though they can only feed on what floats in with the current, hundreds or sometimes thousands of Common Mergansers will concentrate on “Conowingo Pond” during the late fall or early winter.  There, safety in numbers gives them some guarantee of protection against the multitudes of eagles that simultaneously frequent the vicinity.  Another advantage of staging on “Conowingo Pond” is its close proximity to favorable feeding areas on upper Chesapeake Bay and stretches of the Susquehanna where lotic riffles and pools offer abundant opportunities below the river’s dams.
Rusty Crayfish
Fortunately for everything else living in the benthos, Common Mergansers are big enough to devour invasive, non-native Rusty Crayfish when they find them in our lotic waterways.

TIME TO CLEAN UP OUR ACT

WHERE DOES YOUR STORMWATER GO?

 

Channelized Urban/Suburban Streams Function as Sewers. They have no attached lowlands or floodplains to absorb, purify, and infiltrate runoff from rain events.  Pollutants including litter, pet waste, lawn chemicals, tire-wear particles, hazardous fluids, and sometimes untreated human excrement flush unchecked from the municipal storm drainage system into the waterway.  Thermal shock from summer downpours washing across sun-heated pavements can kill temperature sensitive fishes and other aquatic life.  Nutrient and sediment loads from these impaired tributaries later accumulate downstream in low-gradient segments of the Susquehanna, turning the river into an open-air cesspool.  Aggressively working to implement projects that eliminate these sources of pollution are the only effective way to keep the problem from getting worse.  Making things better requires a lot more dedication and effort.  (United States Geological Survey image by Frank Ippolito)

RIPARIAN BUFFERS MAKE A DIFFERENCE…WIDER IS BETTER

Riparian Buffer
To sequester sediment and cycle nutrients (primarily nitrogen and phosphorus) contained in farm runoff, the U.S.D.A. recommends installing riparian buffers between streams and lands used for grazing and raising crops.  To protect pollinating species including bees and butterflies from pesticide drift and eroding soils rich in fertilizers, they further recommend installing a stand of wind-pollinating plants such as conifers, oaks, and birches between the field and streamside plantings.  These same conservation practices improve water quality and wildlife habitat on waterways located in residential and commercial areas as well.  (United States Department of Agriculture image, click to enlarge)

FLOODPLAIN RESTORATION

Regardless OF HOW LONG YOU’VE BEEN CONDITIONED TO THINK OTHERWISE, THIS IS A DYSFUNCTIONAL, POLLUTED CREEK—AND IT NEEDS HELP
Legacy Sediments
A channelized low-gradient stream eroding a path through deposits of legacy sediments displaces flood waters into previously unaffected areas and provides a continuing source of nutrient and sediment pollution during storm events.  These impaired waters have a diminished capacity for supporting aquatic life including fishes.
RESTORED TO ITS HISTORIC FUNCTIONS
Floodplain and Stream Restoration
On an adjacent segment of the same creek, this legacy sediment removal project restored a braided meandering channel and connected it to its newly liberated, historic floodplain.  In just their second year, the fluvial wetlands are effectively absorbing stormwater and sequestering nutrients as an attached component of the stream’s riffle and pool complex.  During our visit earlier this week, we found American Toads, Northern Leopard Frogs (Lithobates pipiens), and Northern Spring Peepers breeding here.  It’s just as Castor canadensis would have it!

“STOP HEMMING AND HAWING AROUND ALREADY”

“HEY COWBOY, HOW ‘BOUT GETTIN’ THEM FILTHY LITTLE DOGIES OUTTA DAT CRICK?”
Impaired Stream
Here’s a polluted stream in a pasture with grazing livestock.  The site is a former mill pond within which the creek eroded a channel following removal of the dam.  The animals defecate and urinate where access to water is gained at a broken down embankment of the nutrient-loaded legacy sediments deposited in the pond more than a century ago.  It’s a haphazard form of animal husbandry and a reminder that all it takes is just one stubborn jackass to foul up the whole waterway.
DIRECT SOURCES OF NITROGEN (AMMONIA) POLLUTION IN STREAMS

DID YOU KNOW that a dairy cow produces about 80 pounds of waste (excrement and urine) every day?

DID YOU KNOW that a horse produces about 50 pounds of waste (excrement and urine) every day?

DID YOU KNOW that a human produces about 3 to 4 pounds of waste (excrement and urine) every day?  The exceptions, of course, are those who continue to insist that raising farm animals in and alongside a body of water is okey-doke—a harmless practice.  These individuals tend to retain the former constituent of human waste and are thus full of it.

“ATTABOY TEX, THAT’S MORE LIKE IT!”
Stream Fencing and Livestock Crossing
Now that’s better.  Legacy sediments have been removed to reconnect the stream to its floodplain.  A livestock crossing and exclusion fencing has been installed, and a nutrient-consuming riparian buffer has been planted.  This creek segment’s pollution woes have been mitigated.  Do you have a neighbor needing this type of remedial work on their farm?  Encourage them to contact your local county conservation district office or volunteer waterways restoration organization for assistance.  Various programs provide financial assistance covering all or most of the costs of stream improvement as well as monetary incentives for helping to clean up the water.

AND FINALLY

WHEN IT COMES TO BUILDING DAMS ON LOTIC FRESH WATERS…

Sandhill Cranes in Beaver Pond

…LEAVE IT TO THE BEAVERS
North American Beavers
North American Beavers (Castor canadensis) create habitats that connect the riffle and pool regime of a low-gradient stream to a surrounding fluvial wetland that retains sediments, cycles nutrients, and provides essential habitat for hundreds of plant and animal species.  Floodplains are for flooding, and if a beaver floods an area, you can be guaranteed that it was already part of a floodplain.  You see, beavers don’t encroach upon humans, it’s humans engaging in the encroachment upon beavers.  (National Park Service image)
MAD HATTERS

DID YOU KNOW that even before the landscape was cleared for farms and a supply of timber, and before mill dams on local creeks began accumulating soil runoff from the consequently barren hillsides, all the North American Beavers, the keystone species of lower Susquehanna stream ecology, were killed and sold to make hats?  It’s no wonder things are fubar!

COMING SOON…

Horned Grebe
Horned Grebes are regular migrants and sometimes winter residents on ice-free stretches of the lower Susquehanna.  They spend their time plying the benthic substrate of the river’s clear riffles and pools for a variety of invertebrates and small fish.  Look for them moving north in coming days sporting this beautiful breeding plumage.
Common Loon
April and early May are prime time for observing Common Loons on the Susquehanna as they undertake a journey from the Atlantic surf where they spent the winter to nesting sites on northern lakes.  For this migrant in breeding plumage, clear water for sighting plenty of benthic life in the river’s riffles and pools assures a successful dive in search of energy-replenishing forage.
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Photo of the Day

Tree Swallow
With southerly breezes to push them along, insectivorous songbirds are beginning to arrive throughout the lower Susquehanna valley.  By the first week of March, Tree Swallows started their push up the river corridor, relying upon the late-winter hatches of stoneflies and other cold-hardy flying insects for sustenance.  As temperatures warmed during mid-month, greater numbers of these colorful cavity nesters ventured out across upland areas in search of suitable breeding sites in grasslands and pastures near water.  Upon finding a good home in a dead tree or nest box, they’ll defend it vigorously to discourage encroachment.
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The Next Wave

Our first big wave of northbound migrants has come and gone, but don’t despair; for spring is still a few days away, and we have yet to reach the end of the beginning …

Migrating Canada Geese
All but the last of the migratory Canada Geese have passed through the lower Susquehanna basin en route to their nesting grounds in the land for which they are named.  Those that remain are mostly members of a resident population established here during the latter decades of the twentieth century.
Migrating Tundra Swans
The majority of the northwest-flying Tundra Swans that wintered on the Atlantic Coastal Plain and will nest in Alaska and western Canada have now traversed our skies and are on their way through the Eastern Great Lakes region.
Snow Goose
Snow Geese too have departed.  Only stragglers like this individual with a wounded wing linger.
Migrating Ring-billed Gulls
Still moving up the river corridor are thousands of Ring-billed Gulls.  Their movements are prolonged, extending through much of the late winter and into early spring with primarily adult birds leading the way.
Red-winged Blackbird
The Red-winged Blackbird exodus continues as well with mostly male birds like this one venturing on ahead of the females to secure suitable breeding sites before the arrival of the competition.
Displaying Common Grackle
Male Common Grackles are coming north to lay claim to favorable nesting habitat too.  In an effort to fend off rivals, a male will thrust back his head and ruffle his feathers to display the colorful sheen adorning his plumage.
Fish Crow
Recognized by their nasal two-syllable calls, Fish Crows have been filtering up the valleys of the river’s main stem and its tributaries for almost a month now.  While the closely related American Crow is numerous throughout the winter in the lower Susquehanna watershed, most of our Fish Crows retreat to the Atlantic Coastal Plain during the colder months.  
Fish Crows
The Fish Crows that return early stake claims on the best nest sites, often in lowland areas where they are sometimes in direct competition with a portion of the population of American Crows that commonly breeds here.

With the arrival of the spring equinox, longer periods of daylight will accompany the return of many more species.  Be sure to get outside, then have a look around.

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Look, Up in the Sky, It’s a Bird, No, Wait, It’s a Bunch of Birds!

Step outside, take a listen, and look up.  A substantial northward movement of early migrants is, at this writing, underway across the lower Susquehanna basin—primarily in the skies within five to maybe ten miles of the river corridor.  Within the last hour, we witnessed a steady parade of geese, swans, and blackbirds in the skies above the headquarters garden.  These are not birds that are staging or are in the midst of a stopover here during their journey north.  They are instead flocks taking advantage of favorable conditions to make a big jump from Chesapeake Bay and adjacent areas of the Atlantic Coastal Plain into territory to our north and northwest that was just two weeks ago in the middle of a deep freeze.  Compared to the slowpokes whose northbound movements are a bit more cautious, the shared determination of these birds to get to the nesting grounds first may be advantageous for their breeding success.

Migrating Canada Geese
At least 2,000 migrating Canada Geese passed high above as we strained to see their silhouettes in the sun-drenched haze.
Canada Geese and Blackbirds
Below them, flocks of hundreds of blackbirds including these Common Grackles and Red-winged Blackbirds filtered through.
Migrating Tundra Swans
Perhaps most spectacular were the 1,000 or more Tundra Swans that passed by.  Each year in late February or early March, we look forward to a day or more with a big push of these regal giants.  But you need to get a good look fast…
Tundra Swans
…because they’re gone in just moments for another year.

Winds from the southwest are forecast for the coming couple of days, so the movements could continue.  Head outside, enjoy the weather, and look up.

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Do Chipmunks Really Eat All That Food They Stash Away in the Fall?

Eastern Chipmunks are familiar mammals of our deciduous forests and wooded neighborhoods.  They are surprisingly solitary and territorial, defending their well-concealed underground excavations vigorously to protect them from would-be intruders—including other chipmunks.  Their individual effort to stockpile a cache of seeds, nuts, and other non-perishable foods during the autumn will largely determine whether or not they survive winter’s worst.

Eastern Chipmunk gathering deeds in autumn
Everyone knows that Eastern Chipmunks spend much of the fall storing provisions for consumption as snacks during breaks in their winter slumbers, but did you realize that those chipmunks with the best inventory will have a pronounced advantage over less successful neighbors come late winter and spring?
Male Eastern Chipmunk
Upon exiting their subterranean shelters earlier this week, Eastern Chipmunks commenced the courting ritual which includes males like this one chasing other males away from both their dens…
Female Eastern Chipmunk
…and prospective mates like this female trying to escape notice by hiding in a hollow stump.
Eastern Chipmunks
Being well-nourished throughout the winter has adequately prepared this male (right) for the strenuous activity of securing both his territory and his mate against other males.
Eastern Chipmunks
Once  certain that their will be no interruptions, the male approaches the timid female.  Finding him fit and acceptable,…
Eastern Chipmunks Copulating
…she becomes receptive to his advances.  A well-fed pair of chipmunks can complete courtship and mating within hours of emerging from their winter abodes.
Male Eastern Chipmunk
Following copulation, the male exits the female’s hideout.  The two part ways and after about 31 days the female will give birth to up to six young.  She will rely, at least in part, upon her inventory of stored food to get her through her pregnancy and the nursing of the offspring.  The more success she had last fall while collecting edibles, the more success she’ll have getting an early start on the spring breeding season, a time of year when venturing out to forage can be marginally productive and especially risky for a small diurnal rodent.  Later, while wild foods are plentiful during the summer, many Eastern Chipmunks will mate again and the female will raise a second litter.  Then, as summer comes to an end, its time to start taking advantage of the abundance to replenish the winter pantry all over again.
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It’s Snow Goose Time at Middle Creek

In case you haven’t already heard, the Snow Geese are at last filtering north from the Atlantic Coastal Plain to congregate at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area in Lancaster and Lebanon Counties.

Snow Geese
Compared to recent years, the 2026 spring waterfowl migration has been a bit behind schedule, owing primarily to persisting layers of ice and snow.  As the cover melted from regional fields during the past week, Snow Geese were at last able to find sufficient acreage for grazing, and their numbers at Middle Creek increased rapidly.
Snow Geese at Middle Creek W.M.A.
As many as 60,000 Snow Geese have been enumerated in recent days at the refuge.
Tundra Swans at Midle Creek WMA
And more than 500 Tundra Swans are making a stopover.
Snow Geese at Willow Point
When not in the fields feeding, Snow Geese are concentrated around the small area of open water on the otherwise frozen lake, making them easily observed from the Willow Point viewing area.  If you’re planning to visit and have a look, don’t wait.  The urge to begin their 2,000-mile journey to breeding areas on the arctic tundra is strong, and as soon as conditions permit, they’ll be resuming their excursion.  This could very well be an abbreviated stay.
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Start Your Own Tree Nursery

Just a reminder—there’s still time to order trees and shrubs from your local county conservation district’s annual sale, but you need to act soon…

Cumberland County Conservation District 48th Annual Tree Seedling Sale

Order by Friday, March 20, 2026

Pick Up on Thursday, April 16, 2026, or Friday, April 17, 2026

 

Dauphin County Conservation District Seedling Sale

Order by Monday, March 16, 2026

Pick Up on Thursday, April 23, 2026, or Friday, April 24, 2026

 

Franklin County Conservation District Tree Seedling Sale

Order by Tuesday, March 17, 2026

Pick Up on Thursday, April 23, 2026

 

Huntingdon County Conservation District Tree/Seedling Sale

Order by Friday, April 3, 2026

Pick Up on Thursday, April 16, 2026, or Friday, April 17, 2026

 

Lancaster County Conservation District Annual Tree Seedling Sale

Order by Friday, March 6, 2026

Pick Up on Friday, April 10, 2026

 

Lebanon County Conservation District ALL NATIVE! Tree & Plant Sale

Order by Monday, March 2, 2026

Pick Up on Friday, April 17, 2026

 

Mifflin County Conservation District Tree Sale

Order by Friday, March 6, 2026

Pick Up on Wednesday, April 15, 2026, or Thursday, April 16, 2026

 

Schuylkill County Conservation District/Sweet Arrow Lake Conservation Association 51st Annual Seedling Sale

Order by Saturday, March 21, 2026

Pick Up on Saturday, May 2, 2026

 

Snyder County Conservation District Tree Seedling Sale

Order by Monday, March 30, 2026

Pick Up on Wednesday, April 15, 2026

 

York County Conservation District Seedling Sale

Order by Sunday, March 15, 2026

Pick Up on Thursday, April 16, 2026

 

If maybe you would like to order trees but you’re not quite ready to put them in the ground, why not pot them up and start your own plant nursery.  It’s a great way to build an inventory of hardy stock for planting around your own property or for use in community or civic conservation projects.

Potting Sweetgum Seedlings
Earlier this week we potted up some bare-root seedlings in a mix of compost and sand to give them a head start before planting them in the ground either during the coming fall or in years to come.  These happen to be some young American Sweetgum trees we purchased from a nursery in Perkasie, Bucks County, Pennsylvania.
Native Tree Nursery
After watering them in, we added our new trees to the inventory we have available for stream buffers, rain gardens, reforestation, and other rewilding projects.  We’ll either stake or trim them to remedy the curved stems.
Yellow Birch Sapling
In just a season or two, we have nice robust saplings ready to install in a project or in the headquarters garden.  Starting plants in the nursery gives them the size they need to improve their chances of survival.
Norway Spruce
This is one of ten Norway Spruce trees we purchased in a pack from a local conservation district sale almost ten years ago.  We started each two-year-old seedling in a pot, then transplanted them into the ground a year later.  All have been thriving ever since.
Eastern Sycamore
Since being installed as a potted sapling reared in the headquarters nursery about fifteen years ago, this sturdy Eastern Sycamore has matured and is producing seeds relished by American Goldfinches and other birds.
Eastern Sycamore and Conifers
Growing in a streamside woodland, a really massive sycamore that got its start in your nursery could continue to provide valuable wildlife habitat over a lifespan extending one hundred, two hundred, maybe even three hundred years or more.  These long-lived denizens of the floodplain provide homes for such beloved breeding birds as Baltimore Orioles, Bald Eagles, Warbling Vireos, Yellow-throated Warblers, and several species of owls,…
Great Horned Owl Nest in Eastern Sycamore
…including this Great Horned Owl, seen currently incubating eggs inside a legacy sycamore that has been an active nest site among its neighboring Norway Spruces and Eastern White Pines for decades.
Yellow-crowned Night Herons at Nest
Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore planted during the early twentieth century as a street tree very near the Susquehanna in mid-town Harrisburg.  Ordering and planting trees today is essential for their tomorrow.
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Adapting to Winter Extremes

During winter’s harshest conditions, one must frequently marvel at the methods various forms of wildlife have to survive.  Take a look at some of the animals we found using their life-sustaining adaptations to find food amidst the snow-covered landscape and bitter cold air.

Blue Jay
We watched this Blue Jay digging to retrieve an acorn from beneath the tuft of leaves and dried grasses where it had apparently concealed it earlier in the season.
Blue Jay Eating Acorn
It then carried it to a nearby limb and chiseled away the husk to devour the nutritious contents.  Blue Jays are known to cache hundreds or even thousands of seeds, nuts, and acorns for winter consumption.  Want to see it for yourself?  Just put out some unshelled no-salt peanuts and watch the jays haul them away, that is if the hoarding squirrels don’t get them first!
Red-headed Woodpecker
Like other members of the Picidae family, Red-headed Woodpeckers pry and chisel away at decaying and insect-infested trees to find food during the winter.
First-winter Red-headed Woodpecker
Like jays, Red-headed Woodpeckers including this first-winter bird are very fond of acorns and will often collect them from the ground.  And like jays, they’ll cache acorns for use as a backup supply when a blanket of snow may prevent them from gathering those that remain beneath the oaks.
Wintercreeper
Native to eastern Asia, Wintercreeper (Euonymus fortunei) has escaped from mostly urban cultivation to become naturalized and often invasive in some wooded areas of the lower Susquehanna River watershed.  It can be quite aggressive, usually found growing as a climbing vine or less frequently as a shrub.  In the absence of native and more palatable foods, the berries are an attractive survival fare for members of the Turidae (thrush) family and other birds.
American Robin
We found this and several hundred more American Robins surviving the current winter weather while feeding on Wintercreeper in a suburban woods with a heavy growth of the invasive plant.
Eastern Bluebird
Several Eastern Bluebirds were seen among the Wintercreeper tangles as well.  They too are relying upon this non-native plant to provide at least a portion of the energy they need to make through blustery February nights.
Hermit Thrush
The Hermit Thrush, a species that nests in the coniferous and mixed forests of the northern United States and Canada, winters sparingly in the lower Susquehanna valley.  We found this one among the robins and bluebirds of the Wintercreeper thicket where it too was probably attracted by the supply of berries.
Brown Creeper
Frequently escaping notice in the winter woods is the Brown Creeper, another species that nests primarily in coniferous and mixed forests to our north, though it does breed in our area at scattered locations, primarily in mountainous or swampy terrain.
Brown Creeper
As their name suggests, Brown Creepers spend nearly all of their time creeping along the bark of mature trees searching for small insects, spiders, and other arthropods and their eggs.  The creeper’s diet changes little with the seasons, but you may occasionally see them visit your bird feeders in winter for a nip of suet.
Winter Wren
The petite Winter Wren exhibits mouse-like behavior as it hops and crawls among logs, rocks, and brush along the banks of wooded waterways.  Like the creeper, it is primarily an insectivore, spending much of its time escaping notice searching beneath streamside structure for its daily nourishment.  In summer, Winter Wrens nest in damp coniferous forests.
Red Fox
Seeing a Red Fox repeatedly during daylight hours is typically considered to be a sign that one may be observing a diseased animal, but we soon determined that there was nothing at all wrong with this vulpid we found patrolling a large woodland lying along the outskirts of a lower Susquehanna city.
Red Fox
Typically when the ground is covered with snow, a Red Fox will hunt for voles or mice by listening for their movements in the runways below, then leaping and pouncing to plunge snout first into the fluff to grab the pinpointed prey.  But the recent rain-soaked snow which is now frozen rock hard prohibits the usual hunting tactic, so this canine has adapted to current conditions.
Red Fox
It has switched from its habitually nocturnal schedule to a day shift in pursuit of a diurnal species of prey rodent which can currently be found in abundance at ground level.  After about forty minutes of watching this fox dart back and forth through the understory growth without ever paying much attention to us, we became certain of its target when the alarm chatter turned to a series of screams as one of the numerous Eastern Gray Squirrels that had been scurrying around fell into the fox’s grip.
Red Fox
Just as suddenly as it had begun, our Red Fox encounter ended as our visitor opted to carry away its quarry and dine in peace.  From all appearances, this particular fox’s only ailment was hunger.  By adapting to prevailing conditions, it was able to fully utilize its opportunistic feeding traits and may thus survive to pass on these qualities to the next generation of Red Foxes.  As for the squirrel, it exhibited a vulnerability that led to its demise.  This vulnerability will not be passed on to a future generation of squirrels.  Though it may run counter to public perception and understanding, the event strengthens local populations of both native species.  And so it goes.
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Today’s Middle Creek Snow Goose Count: One

For those of you who may be wondering if there are Snow Geese at Middle Creek Wildlife Management Area, the answer is yes—just one!

Snow Goose
A lone Snow Goose was seen earlier today among about 100 Canada Geese, two dozen Tundra Swans, and a couple of American Black Ducks clustered around a small opening in the ice on the main impoundment at Middle Creek.

So where are the thousands of Snow Geese we’ve grown accustomed to seeing during recent decades as they gather at the refuge in February while preparing to fly north for the summer?

With much of the river and nearly all of the lower Susquehanna basin’s lakes and ponds frozen, Snow Geese and many other migratory waterfowl remain concentrated on the Atlantic Coastal Plain where salty tidewater provides ice-free conditions for feeding and loafing.  In fact, some ducks, particularly diving species, may still be evacuating freshwater locations to our north such as the Eastern Great Lakes where, during the past week, even more surface area has succumbed to freezing.  Look for migrants to begin pushing north in bigger numbers as soon as rising temperatures start to melt local ice.  (NOAA/U.S. National Ice Center image)
Freezing of the Great Lakes has not been this extensive since 2019.  New lake ice (shown in pink) has completed coverage of Lake Erie (lower left), isolated open water from the shorelines of Lake Huron (upper left), and now covers a large portion of the nearshore waters of Lake Ontario (right).  (NOAA/U.S. National Ice Center image)
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To Stave Off Starvation, Nip It in the Bud

It looks like the worst of the cold may be behind us.  With temperatures trending upwards during the coming days and weeks, some species of wildlife will soon find their search for food made a whole lot easier.

White-crowned Sparrow
White-crowned Sparrows spend the winter seeking shelter in dense tangles of early successional growth, particularly among thorny shrubs and vines.  Extended periods with snow cover can  make their search for food a real challenge, but we spotted this one hitting the jackpot on a bare patch of sun-drenched ground along the edge of a thicket of briars.  It has found the earliest green buds of a clover or other herbaceous plant.  Many songbirds in the finch, cardinal, and sparrow families turn to buds in late winter and early spring as a source of energy-rich sugars.
Eastern Gray Squirrel
In woodlands, sweet sap will soon swell the buds of maples, much to the delight of Eastern Gray Squirrels whose favorite dining spot will suddenly become the treetops instead of the leaf litter.  Often selected by property owners for their colorful autumn foliage and fast growth, the prevalence of both native and non-native maples in the suburban landscape helps more squirrels survive the winter to expand their numbers in the spring.
White-tailed Deity
Nibbling late-winter buds is a daylong pastime for the hungry White-tailed Deity.  While high-intensity twig browsing can alter forest ecology and practically eliminate understory growth and regeneration, bud snacking only tends to make some of the trees more stout than others.  It’s similar to the trimming and snipping a bonsai artist may do to maintain a  prized specimen.
Tree Shelters Protecting Saplings
Those of you installing stream buffers or reforesting all or part of your property may not want your newly planted trees turned into bonsai or lost entirely to hungry ungulates.  If you’re seeking some relief from a browsing problem, you’ve got to nip it in the bud.  Tree shelters offer protection during the first half a decade or more of your sapling’s new life.  You can find these tubes for sale from many online sources including some of the local county conservation districts during their annual spring tree sales (which happen to be underway right now, hint-hint).  Installing these plastic protectors may not only relieve you from the frustration of worrying about your new trees, it might also excuse you from risking involvement in the sometimes heated quarrel between the worshipers of the White-tailed Deity who practice sacrifice and those who religiously oppose it.
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