Photo of the Day

Common Carp
We came across this photo from a dive we did back in 1999 and thought it timely.  Here a large non-native Common Carp churns up a cloud of nutrient-charged sediment as it roots its way through a bed of American Eelgrass and Water Stargrass in the Susquehanna below Conewago Falls.  (Vintage 35 mm image)

Common Carp: A Menace Meant for the Dinner Plate

One of the earliest non-native fish species to be widely released into North American waterways was the Common Carp.  Stocks brought to the United States were likely sourced from populations already naturalized throughout much of western Europe after introductions originating from the fish’s native range in Eurasia, probably including the Danube and other watersheds east through the Volga.  In western Europe, the species promised to be an abundant and easily cultivated food source.  Under the same premise, carp were transported to the United States during the early 1800s and widely introduced into streams, lakes, and rivers throughout the country.

Common Carp thrive in nutrient-rich waters, particularly those subjected to sewage discharge and agricultural runoff, conditions which were already prevalent during the Common Carp’s initial introduction and have remained widespread ever since.  Within these polluted streams, lakes, and ponds, introduced carp feed aggressively on benthic organisms and plants, stirring up decaying organic matter (mulm) from the substrate.  This process raises turbidity in the water column and releases excessive amounts of the nutrient phosphorus resulting in unusually large algal blooms.  Algal blooms can block sunlight from the longer-lived oxygen-producing vascular plants that grow in submerged environs.  Growing beneath a dense cloud or blanket of algae can compromise the vigor of oxygen-producing vascular plants and disable their biochemical functions within the aquatic ecosystem.  As the short-lived algae die, the bacteria that decay them begin to place increased oxygen demands on the water.  With less oxygen being produced by both the vascular plants and the algae, and with oxygen consumption increased by the activity of decomposers, conditions can become fatal for fish and other organisms.  This process is known as eutrophication.  Because Common Carp are among the species most tolerant of eutrophic conditions, they tend to thrive in the conditions they create while the native fishes perish.

Common Carp spawn in the spring, usually from late April through June, when the water temperature is as low as 58 degrees and as high as 83 degrees Fahrenheit.  This activity is often triggered by a rapid increase in water temperature.  In a small lake, this may be brought on by a string of sunny days in late April or May.  On larger streams and rivers, the temperature spike that initiates the spawn may not occur until warm rains and runoff enter the stream during June.

Common Carp
Seeing the exposed backs of Common Carp as they stir up mulm and other sediments while feeding along the edges of a body of water is not at all unusual.
Common Carp
But carp pursuing other carp into the shallows is a sign that spawning has commenced.
Common Carp Spawning
In water that is often less than a foot in depth, male carp follow the breeding females into egg-laying areas among debris and emergent vegetation.
Common Carp Spawning
A fountain of splashes can ensue as males try to outdo one another for a chance to fertilize the female’s eggs.
Common Carp Spawning
The males’ aggressive pursuit can even forced a large female to temporarily ground herself on the beach.

Common Carp are one of the most widely farmed and eaten fish in all the world.  Here in the United States, they were introduced beginning two hundred years ago because they were favorable to the palate, grew to large size quickly, and were a source of much needed food.  Today, the Common Carp is seldom found on the American dinner plate.  Yet, pound for pound, it is one of the most abundant fish in many of our waters, particularly in man-made lakes.  Like some of our other most invasive species—including Blue Catfish, Flathead Catfish, and Northern Snakehead—Common Carp are perhaps the most edible of our freshwater fishes.  For many cultures, they are an important staple.  For others, they are a delicacy or holiday treat.  In America, they do horrendous damage to aquatic ecosystems following establishment as a food crop that almost never gets harvested.  Did you realize that on the internet, there are literally hundreds of recipes and culinary videos available to show you how to prepare delicious dishes made with Common Carp?  It’s true.  And for the cost of a fishing license, you can catch all you want, usually several pounds at a time.  So why not give the marine fisheries a break?  Take the big leap and learn to eat invasive freshwater species instead.

Common Carp Breaching
Jumpin’ gefilte fish, it’s what’s for dinner!

Soakin’ Up the Smoky Sun

With temperatures finally climbing to seasonable levels and with stormy sun filtering through the yellow-brown smoke coming our way courtesy of wildfires in Alberta and other parts of central Canada, we ventured out to see what might be basking in our local star’s refracted rays…

Black Saddlebags
Dragonflies including this Black Saddlebags are now actively patrolling the edges of waterways and wetlands for prey and mates.
Common Green Darners
Here we see a pair of Common Green Darners flying in tandem…
Common Green Darners
…and, having already mated, stopping at a suitable location for the female to oviposit the fertilized eggs onto submerged plant stems.
Painted Turtles
A sunny day almost always brings out the reptiles, including these Painted Turtles…
Red-eared Slider
and the invasive Red-eared Slider, a native transplant from the American midwest.
Snapping Turtle
A really big Snapping Turtle will prey on almost anything, including other Snapping Turtles…
Golden Shiners
…but this one seems to be fascinated by something a lot smaller.  Something like these juvenile Golden Shiners seen here schooling in the sun-drenched shallows.
Northern Water Snakes
Turtles aren’t the only reptiles thriving in the heat.  Northern Water Snakes (Nerodia sipedon sipedon) take full advantage of a sun-drenched rock to warm up after spending time in the chilly water of a stream.
Northern Water Snakes
You know, no one loves a snake like another snake…
Northern Water Snakes
…and when it comes to these two snakes, it looks like love is in the air!
Spicebush Swallowtail
Butterflies like this Spicebush Swallowtail enjoy time in the sun, even while seeking out minerals in a patch of moist soil.
Woodchucks
After its siblings darted into the familial burrow upon our approach, this juvenile Woodchuck instead sought the attention of its nurturing mother.  Unlike its brothers and sisters, perhaps this little groundhog isn’t afraid of its own shadow.  Or does the smoky haze have the youngster all confused about what does and doesn’t constitute as a shadow?  Well, we can’t help you there, but you have a whole eight months to figure it out!

Shad Run at Conowingo Dam

As the Flowering Dogwoods remind us, it’s time for adult sea-run shad and other fishes to ascend the Susquehanna to spawn.  So yep, we’re off to Fisherman’s Park on the river’s west shoreline below Conowingo Dam in Harford County, Maryland, to check it out.

Anglers at Conowingo Dam
Anglers were in the water and seeing action as we arrived below Conowingo Dam’s powerhouse at Fisherman’s Park.  The east lift, which was constructed during the 1990s to raise American Shad and other migratory fish over the dam during their spring spawning runs, sits idle at the impoundment end of the wing wall in the distance.
The entrance to the idle east fish lift at Conowingo Dam.
The entrance to the idle east fish lift at Conowingo Dam.
Northern Snakehead
Within minutes, we watched one of the culprits responsible for the lift’s shutdown being reeled in.  The invasive population of introduced Northern Snakeheads continues to thrive in the waters of the Susquehanna and its tributaries below the dam.  To prevent it from expanding its range to upriver sections of the watershed, all American Shad are being manually separated from among the snakeheads and other fish species deposited into sorting tanks using the west lift near the powerhouse.
Shad Transport Truck
One of several specialized transport vehicles returns from a “shad run” to the waters of the Susquehanna above York Haven Dam at Conewago Falls after delivering and releasing American Shad sorted from among the fish collected at Conowingo’s west lift earlier in the day.
American Shad began their run up the Susquehanna as water temperatures reached 60 degrees Fahrenheit…just about the time the Flowering Dogwoods started to bloom within the river’s riparian woodlands.  Later this month, spawning activity peaks when the water warms to about 65 degrees.  Earlier in the season, when the water reached about 55 degrees, another anadromous species, the Hickory Shad (seen here), began their spring spawning run from sea to freshwater rivers and streams.
While American Shad are seldom caught on hook and line, Hickory Shad are a popular catch-and-release target.  Though they will energetically strike baits like the small shad dart seen here, Hickory Shad are very cautious while ascending the river; they very rarely enter the fish lifts to join the dozens of other species that readily accept their use.  With water temperatures now in the sixties, an angler is seen here bringing in what may be among the last of this season’s Hickory Shad.  Their spawning run is presently drawing to a close for the year.
Gizzard Shad
The most commonly caught herring at Fisherman’s Park is the Gizzard Shad.  This plankton feeder seldom takes bait; it is instead foul-hooked.  Though not a sea-run species, Gizzard Shad by the tens of thousands leave open waters to seek shallower flowing riffles and pools to spawn.
Gizzard Shad
Unlike the other herring occurring in the Susquehanna, the Gizzard Shad has a blunt, snub-nosed appearance to the snout. The mouth is small and often unnoticeable.
Gizzard Shad
The Gizzard Shad is the only species of Susquehanna herring that can legally be harvested.  All others are sea-run migrants in varying degrees of population peril and must be returned to the water without delay.
Gizzard Shad
Note the elongated last ray on the dorsal fin of this foul-hooked Gizzard Shad.  It’s a not-often-visible but nevertheless tell-tale field mark.
Double-crested Cormorant
Humans aren’t the only creatures attracted by the fish migration on the lower Susquehanna.  This is just one of hundreds of Double-crested Cormorants we watched during our visit.
Cormorant along the base of Conowingo Dam
Hungry cormorants gather along the base of the dam where ascending fish congregate and become further disoriented by water turbulence.
Double-crested Cormorants
Fishing efforts here can bring great success to these accomplished piscivores.
Double-crested Cormorant with Gizzard Shad
Latching onto an oversize Gizzard Shad can make you very popular with your peers.
Double-crested Cormorant with Gizzard Shad
So popular that you may never have the opportunity to eat your lunch.
Double-crested Cormorant with Gizzard Shad
Take it from this old bird: you’ve gotta swallow ’em fast, head first, tail and all.
Bald Eagle with Gizzard Shad
A Bald Eagle hauls off a Gizzard Shad.
Osprey with Gizzard Shad
An Osprey saw this Gizzard Shad swimming close enough to the water’s surface to dive in and snag it with its talons.
Bald Eagle with Gizzard Shad
And yet another successful Bald Eagle calls out to its mate as it approaches its nest and hungry young.
Striped Bass
An angler releases a small Striped Bass caught on a shad dart while fishing for Hickory Shad.  To reduce pressure on their populations during the spring spawning run, the “Striper” harvest is presently closed.  The fishing season resumes later this month in some areas, in June within others.  On the Susquehanna Flats and other Chesapeake Bay waters, Striped Bass are also known as “Rockfish”.
Angler in Action
This angler is reeling in a big one.
Channel Catfish
A nice Channel Catfish weighed in at about six pounds and was released.
White Perch
This angler brought in yet another interesting catch.
White Perch
The White Perch (Morone americana) is a bay species that ascends the Chesapeake’s tributaries to spawn during the spring.  On the lower Susquehanna, numbers of this relative of the Striped Bass are falling, very possibly due to depredation by invasive snakeheads, Blue Catfish, and Flathead Catfish.
Double-crested Cormorant with Blue Catfish
A Double-crested Cormorant does its duty and snatches up an invasive Blue Catfish.   Very large Blue Catfish exceeding 24 inches in length are becoming increasingly plentiful on the upper Chesapeake and its tributaries resulting in a significant negative impact on the aquatic ecosystems there.  Like the Northern Snakehead and Flathead Catfish, these invasive species are very palatable and anglers are encouraged to catch and keep as many as they like.
Maryland DNR sign at Fisherman’s Park.
Angler with Northern Snakehead
What can we do about the plague of Northern Snakeheads (Channa argus) in the Susquehanna?  Well, let’s start by answering a question with a question…Why deplete ocean stocks when you can follow this angler’s example and harvest excellent fillets while helping to control an invasive species at the same time?  And no, you don’t have to call them “Chesapeake Channa” if you don’t want to.  Though you will make us laugh if you start calling them “Susquehanna Channa” or  just “Susquechanna” from time to time.

Three Items to Add to Your Tacklebox to Be a Better Conservationist

Soon after their arrival during the late 1600s, the earliest trans-Atlantic human migrants to settle the Lower Susquehanna River Watershed began the process of eliminating many of our largest native fish species.  They started by extirpating nature’s steward of lowland streams and wetlands, the North American Beaver.  The beaver’s meticulously maintained dams and fisheries-friendly ponds were promptly replaced by man-made impoundments designed to permanently divert water for powering lumber and grain mills.  Behind these structures, silt deposits accumulated as the forests were clear cut and the land subjected to highly erosive farming methods.  Mill dams would eventually be located on nearly every mile of suitable low-gradient stream in the basin.  Populations of native coldwater fishes including Brook Trout were quickly lost or left isolated in scattered headwaters.

With their navigation of creeks blocked by nearly impenetrable mill dams, seasonally migratory freshwater and anadromous fish were denied access to their traditional spawning waters.  The latter then had their populations seriously depleted, and in some cases extirpated, following construction of hydroelectric dams on the lower Susquehanna during the first half of the twentieth century.  The loss these latter species, including the herrings, Striped Bass, and sturgeons, all of which attain great size only because of their ability to make a sea run to access the year-round food energy available in the Atlantic, constitute a tremendous reduction in the numbers, variety, and mass of fish occurring in the river and its tributaries.

Add to these events the various sources of pollution entering the lower Susquehanna’s waterways during the intervening years including acid mine drainage, agricultural nutrients and sediments, stormwater runoff, untreated domestic and industrial sewage, illegal dumping, pesticides, etc., and one can easily understand how the watershed’s native fishery was lost as a commercial, food, and recreational resource.

Presently, the effort to restore populations of self-sustaining anadromous fishes to the lower Susquehanna is stalled due to the presence of introduced invasive species, particularly Northern Snakeheads, in the river’s waters below Conowingo Dam.  Lifts that carry migrating fishes over the lower river’s hydroelectric dams during the spring run are shut down to avoid extending the range of the hoards of non-native snakeheads to waters upstream of their present location.  Any translocation of anadromous fish must now be completed by manually separating desired species from among the invaders and loading them into a tank truck for transport to waters upstream of the dams.  But Northern Snakeheads are currently so prevalent at Conowingo that they are overwhelming the lift used for collecting and sorting fish as well.

Any slight hope that had existed for a return of harvestable stocks of American Shad or other sea-run native species to the Susquehanna and its tributaries seems to be fading.  And widespread improvements to water quality that would promote reestablishment of sustained populations of native coldwater fishes like Brook Trout are strictly a long-range goal.

Recreational anglers, however, still remain in the game—but their reward is a bit of a booby prize.  To compensate fisherman for the loss of their quarry on the river and in streams, and to promote an interest in the fishing pastime and conserving waterways, the stocking of various species of “game fish” has been a continuous undertaking, particular since the middle decades of the twentieth century.  Some of these introductions are planned, others, like the release of Northern Snakeheads, are unsanctioned and outright illegal.  The one thing most introductions have in common is that they consist of hardy, aggressive, predatory fishes that are non-native species (or native transplants from watersheds such as the Mississippi).  Their presence, especially in large concentrations and particularly during the time immediately following introduction, can have a deleterious impact on native stream inhabitants.  Some introduced fish, the Flathead Catfish for example, are upon discovery deemed invasive species; others, like the Smallmouth Bass, escape such a label not because they lack negative impacts on stream communities and ecosystems, but because they have been present for extended periods of time and have thus been accepted as part of the local fishing culture.

Rainbow Trout

Rainbow Trout
Hatchery-raised Rainbow Trout stocked by the hundreds in a lower Susquehanna valley creek for angling.  The Rainbow Trout is native to the streams and rivers of the Pacific coast of North America.  An anadromous form is known as the “Steelhead”.  These sea-run trout with access to marine food sources during their growth years attain more than twice the size of freshwater forms and acquire oversized hooked jaws before ascending waterways to spawn.

The creation of recreational fisheries comprised of introduced species has certainly helped maintain an interest in the fishing hobby and in the conservation of waterways.  It has even been a driving force for spectacular restorations of streams that otherwise would have languished in an impaired condition with little in the way of diversity of species—native or non-native.  As anglers, we are especially indebted to those who’ve devoted their time, energies, and, in some cases, a lot of money to projects that specifically seek to reestablish native waterways within the challenging landscape of the Lower Susquehanna River Watershed.  With an eye on the future, perhaps now is a good time to join them and focus our passion for freshwater angling on steering fisheries management more toward the native ecosystems approach.  Quality instead of quantity.

In that spirit, here are three items we can add to our tackle boxes this season to be better fisheries conservationists, instead of our own worst enemies.

Lead-free Weights
Lead-free Weights-  Replace the lead in your tackle box with tungsten or other lead-free alternatives to eliminate the potential impact this poisonous metal can have on you and wildlife like waterfowl and Bald Eagles.  Make a special effort to rid your inventory of small pieces of shot that can easily be ingested by animals as they feed. 
Realistic Lures
Realistic Lures-  Add sport to your fishing by using artificial lures.  Today’s selections include very realistic versions of native fishes, crayfish, frogs, and other aquatic creatures.  Use these life-like imitations and you won’t need to harvest native minnows and other wildlife from populations that are already being subjected to negative impacts from stocked legions of predatory “game fish”.  You’ll also eliminate the risk of introducing non-native bait species into your favorite fishing waters!
Trash Bag
Trash Bag-  Always bring a trash bag and carry out your litter.  Be especially vigilant about monofilament fishing line.
Fisherman's Trash
Fishermen are their own worst enemies, so you’ll need to pick up after the other guy too.  Show the landowners and land managers who are our hosts a little consideration.

Best of luck this fishing season.  We hope your time outdoors will motivate you to get involved with efforts to keep your local waterways clean.  You might even be inspired to assist with projects that are planned or currently underway in the Lower Susquehanna River Watershed to restore stream segments, wetlands, and floodplains.  Many of these projects are grassroots efforts and they’d love to have your participation.  Your local county conservation district can steer you towards an active restoration group near you.  Give them a ring.

Rainbow Trout and "Golden Rainbow Trout"
Hatchery-raised Rainbow Trout and a “Golden Rainbow Trout” stocked for anglers in a restored segment of a stream in Lebanon County, Pennsylvania.  The “Golden Rainbow Trout”, also known as the “Banana Trout”, is a Rainbow Trout color variant developed through multi-generational selective breeding of offspring produced by crossing a typical male with a yellow-mottled female mutant discovered in a hatchery in West Virginia in 1955.  Today, “Golden Rainbow Trout” breed true, golden males crossed with golden females yielding golden young.  The less colorful “Palomino Rainbow Trout” is produced by crossing a “Golden Rainbow Trout” with a typical Rainbow Trout.

Wildlife in the Burn Zone

During Saturday’s Prescribed Fire Demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area, we noticed just how fast some species of wildlife return to areas subjected to burns administered to maintain grassland habitat and reduce the risk of high-intensity blazes.

Back Fire Ignition during prescribed burn demonstration.
Pennsylvania Game Commission crews ignite a back fire to contain a prescribed burn along its downwind/upslope perimeter during a demonstration at Middle Creek Wildlife Management Area on Saturday.
Prescribed Fire Demonstration
Visitors observe a fire planned to maintain this section of the refuge as warm-season grassland.  A species with roots several feet deep, the light-colored vegetation is Indiangrass, a plant adapted to thrive following periodic episodes of wildfire.  Prescribed fire can be used to replace naturally occurring infernos with much safer controlled burns that eliminate successional and invasive plants to promote the establishment of Indiangrass and other native warm-season species including Big Bluestem, Little Bluestem, Switchgrass, and a variety of wildflowers as well.
Prescribed Fire Demonstration
Even as the fire reached its brief peak of intensity, we noticed birds already attracted to the site…
Tree Swallow
Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.
Tree Swallow
One even stopped by to have a look inside the kestrel nest box as fire approached the dry stand of goldenrod on the slope behind.
Red-tailed Hawk
Red-tailed Hawks and other raptors, including nocturnal owls, are frequently the first visitors attracted to the scene of a prescribed burn or wildfire.  In grassland and successional habitats, they come looking for any vulnerable voles or mice that may be moving about looking for cover.

Eastern Meadowlarks

Eastern Meadowlarks

Eastern Meadowlarks
These three Eastern Meadowlarks spent the morning in the grassland areas adjacent to the prescribed fire site, mostly where a burn had been conducted one week prior.  During the demonstration, one even perched and sang from the oak trees in the museum/visitor’s center parking lot.

Following the Prescribed Fire Demonstration, we decided to pay a visit to some of the parcels where burns had been administered one week earlier on the north side of Middle Creek’s main impoundment.  We found a surprising amount of activity.

White-crowned and White-throated Sparrows
Apparently feeding upon slightly heat-treated seeds, sparrows were found by the dozens. White-crowned (left), White-throated (right), Song, and Savannah Sparrows were identified.
Downy Woodpecker
This Downy Woodpecker was finding something to its liking among the scorched leaves, stems, and twigs.
American Robins seem to find areas with lightly burnt vegetation and ash-dusted soil advantageous for finding invertebrates following a fire.
Mixed Flock of Blackbirds
We found this flock of Red-winged Blackbirds, Browned-headed Cowbirds, and a few European Starlings feeding throughout a grassland field cleared of early-successional growth by a prescribed fire administered one week ago.
Mixed Flock of Blackbirds
They seemed to favor gleaning seeds from among the lightly burned areas of the plot.
Eastern Meadowlark
Nearby, in an island of unburned grass in the same field, we found yet another Eastern Meadowlark, our fourth of the day.  High-intensity agriculture, particularly early hay mowing and pesticide treatments, have mostly eliminated this and other grassland species from modern farms.  Management practices like prescribed fire and delayed mowing (no spinning blades until at least early August) can maintain ideal grassland habitat for stunningly colorful blackbirds including nesting Eastern Meadowlarks, Bobolinks, and many other species as well.
American Kestrel at Nest Box
A male American Kestrel at a nest box located among Middle Creek’s warm-season and cool-season grassland habitats, the former maintained by prescribed fire, the latter by delayed mowing.

Mark Your Calendar: Prescribed Fire Demonstration at Middle Creek Wildlife Management Area

With relative humidity readings regularly dipping below 50%, the sunny days of March and early April are often some of the driest of the year.  During recent weeks, these measurements have plunged to as low as 20%, levels not often observed in our region.  As we’ve seen throughout the lower Susquehanna valley, windy weather and this extraordinarily dry air conspire to create optimal conditions for fast-spreading and often dangerous wildland fires.

On the brighter side, dry weather also provides the opportunity for foresters and other land managers to administer prescribed fire.  These controlled burns are thoroughly planned to reduce accumulations of wildfire fuels and invigorate understory growth in forests.  Their use also provides a number of effective methods for creating and maintaining wildlife habitats in non-forested areas.

Prescribed Fire in Grassland
Prescribed burns are currently underway on many state, federal, and privately-owned lands throughout the Lower Susquehanna River Watershed.

This Saturday, March 22, 2025, crews from the Pennsylvania Game Commission will be hosting a Prescribed Fire Demonstration at Middle Creek Wildlife Management Area in Lancaster/Lebanon Counties.  The event begins at 10:00 AM in the refuge’s museum/visitor’s center parking area.  A controlled burn to “reset” a parcel with early successional growth back to grassland will follow a presentation on prescribed fire uses, planning, safety, and implementation.

Prescribed Burn of Grassland
Prescribed fire treatment being used to prevent succession and maintain a warm-season grassland.
Prescribed Fire in Wetland
Prescribed fire being administered to eliminate successional woody growth from a sedge-rush wetland.
Prescribed Fire in Successional Growth
Pennsylvania Game Commission crews maintain a fire line along an area being burned to control invasive successional growth.
Eastern Cottontail
To best prevent succession, a given area should be burned every three to five years, thus only one fifth to one third of an entire habitat need be subjected to treatment each year.  To flee this year’s prescribed burn, this Eastern Cottontail simply hops across the fire break into an adjacent plot that will be unaffected in 2025.
Ring-necked Pheasants Post-burn
Hen and cockbird Ring-necked Pheasants feeding in a pre-plowed fire break furrow along the northern edge of a prescribed fire plot burned during a south wind.  These birds entered and fed in the area less than an hour after the flames subsided.
Prescribed Fire on Grassland
To provide refuge for evacuating animals, a completed prescribed burn leaves plenty of adjacent grassland acreage untouched.  Within weeks, the fire area will be lush green and again hosting many species of wildlife for the breeding season.  The scorch-free areas will each get a prescribed fire treatment sometime during the coming two to four years, the time period preceding this parcel’s next burn.

Don’t forget: Middle Creek Wildlife Management Area museum/visitor’s center parking lot on Saturday, March 22, 2025, at 10:00 AM.  See you there!

Winter Survival: Generalists and Specialists

We’ve seen worse, but this winter has been particularly tough for birds and mammals in the Lower Susquehanna River Watershed.  Due to the dry conditions of late summer and fall in 2024, the wild food crop of seeds, nuts, berries, and other fare has been less than average.  The cold temperatures make insects hard to come by.  Let’s have a look at how some of our local generalist and specialist species are faring this winter.

House Sparrows and a House Finch
House Sparrows (bottom) and House Finches (top) are generalists.  To survive and thrive, they are adapted to a variety of habitats and types of food.  House Sparrows live almost anywhere man-made structures are found.  They are true omnivores and will eat almost anything, especially if they see something else try to eat it first.  The House Sparrow’s close association with humans has allowed it to become the most widespread and successful living avian dinosaur.  On a cold night, they’ll take shelter either within dense vegetation alongside a building or within the structure itself.  Though not nearly as cosmopolitan, the House Finch has successfully colonized much of the eastern United States after escaping from captivity as a cage bird in New York during the middle of the twentieth century.  Upon being trans-located here from the arid southwest, they adapted to suburbs and farmlands consuming primarily a granivore diet of seeds supplemented with seasonally available berries.  They quickly became accustomed to offerings at bird-feeding stations as well.  To survive the harsh winters in the northern sections of their range, eastern populations of House Finches are developing a pattern of migration.  These movements are most evident in late fall when dozens or sometimes hundreds can be seen heading south over regional hawk-counting stations.
Northern Flicker feeding on Poison Ivy
Though they require dead trees for nesting and as places to find the grubs and adult insects upon which they primarily feed, woodpeckers including the Northern Flicker are generalists, seldom passing by a supply of fruits like these Poison Ivy berries as a source of winter food.  Flickers regularly visit suburban areas where they’ll drop by at bird-feeding stations for suet.  During the warmer months, they are the woodpecker most frequently seen on the ground where swarms of ants garner their full attention.
Pileated Woodpecker
The Pileated Woodpecker is seldom found outside of mature forests where it digs relentlessly to remove grubs and other infestations from dead wood.  But it is not a true specialist…
Pileated Woodpecker eating Poison Ivy
…it too finds a supply of Poison Ivy berries to be indispensable during a cold winter day.
Ruby-crowned Kinglet
The Ruby-crowned Kinglet is a generalist, feeding mostly on insects, but also consuming small seeds and some berries, including those of Poison Ivy.  It nests well to our north in tall spruces and other evergreens.  During migration and in winter, the Ruby-crowned Kinglet may be found in deciduous trees, brush, and tall grass in habitats ranging from forests to parks and suburbia.  This male is displaying its seldom-seen red crown.
Golden-crowned Kingle
The Golden-crowned Kinglet, seen here on a Poison Ivy vine, is more of a specialist than the Ruby-crowned species, though the two will often occur in mixed groups during the winter.  The Golden-crowned Kinglet nests in Spruce-Fir forests and in conifers within mixed woodlands.  Even during migration, and particularly in winter, these birds are seldom found far from a stand of large evergreens within which they find shelter for the night.
Hermit Thrush
The Hermit Thrush’s generalist lifestyle allows it to survive cold season weather in the Lower Susquehanna River Watershed.   During summer, it breeds in coniferous and mixed woods from the northern parts of our valley north into Canada and feeds primarily on worms, insects, and other arthropods.  During migration and in winter, the Hermit Thrush becomes a regular visitor to deciduous forests, woody parks and suburbs, particularly where a supply of wild berries is available to supplement its diet.
American Robin
Iconic as it pulls earthworms from lawns during the warmer months, the generalist American Robin is fully dependent upon a crop of berries to survive winter conditions in the lower Susquehanna valley.  The drought afflicted wild food crop of 2024 has led to fewer robins spending the season here and has delayed the northward push of migrating birds until the ground thaws and the earthworms make the ground rumble once again.
Eastern Bluebirds
It’s insects for the nestlings during spring and summer, then berries through the winter for the cheerful Eastern Bluebirds, another generalist species.
American Crow
American Crows are an excellent example of a generalist species.  They’ll go anywhere to find food and they’ll eat almost anything.  Like the House Sparrow and several other generalists, they adapt very well to human activity and actually thrive on it.  Garbage anyone?
White-tailed Deity
Another career generalist is the widely worshiped White-tailed Deity, a species adapted to nearly all man-made landscapes with adequate vegetation upon which to browse. Pushed to the limit during severe weather, some individuals will consume carrion and even resort to cannibalism.
Great Blue Heron
You might think the Great Blue Heron is a specialist.  Nope, it’s an accomplished generalist.  Great blues will live, feed, and breed on almost any body of fresh or brackish water.  And their diet includes almost anything that swims.  In winter, you’ll even see them in fields hunting mice and voles.
Red-shouldered Hawk
The Red-shouldered Hawk is a generalist with a diet ranging from amphibians and reptiles to small rodents and large insects.  Mostly regarded as a species of bottomlands, they’ll frequent woodland edges, roadsides, and suburbia during the winter months.
American Tree Sparrow
During its periodic winter visits to the region, the American Tree Sparrow feeds on seeds among the grasses and forbs of semi-open country with scattered short shrubs and trees.  A generalist species, it will show up at backyard bird-feeding stations, particularly during periods of inclement weather.  In summer, the American Tree Sparrow nests in tundra with growths of stunted willows and spruce and their diet includes insects as a source of protein for themselves and their young.
White-crowned Sparrow
The White-crowned Sparrow has similar winter habitat preferences to the tree sparrows…
White-crowned Sparrows
…it becomes adaptable and something of a generalist when searching for food during bad winter storms.
Savannah Sparrow
The Savannah Sparrow is an omnivore favoring insects in summer and seeds in winter.  Though very closely tied to its grassland habitat year-round, snow cover can push these birds to enter woodier environs to consume fruits like these rose hips.
Short-eared Owl
Dusk and dawn during the short days of winter are the prime hunting times of a mammal specialist, the Short-eared Owl.  Its presence in the lower Susquehanna valley is dependent on two dominant factors: extensive grassland habitat and an adequate population of the owl’s favored food, the Meadow Vole (Microtus pennsylvanicus).  The Short-eared Owl’s requirements as a specialist species make finding a suitable place to live difficult.  Unlike the generalist birds and mammals that often adapt to the widespread man-made disturbances in the region, populations of specialists frequently become fragmented, reduced in abundance, and subject to extirpation.
Meadow Vole
The Meadow Vole is a generalist rodent that can be abundant in grasslands, early successional growth, fallow fields, marshlands, and, of course, meadows.  They are primarily herbivores, but will occasionally consume insects and other arthropods.  Usually nocturnal, some individuals venture out along their surface runways during daylight hours becoming vulnerable to diurnal raptors including kestrels, harriers, and buteos.
Short-eared Owl patrolling a grassland for Meadow Voles
A Short-eared Owl in near darkness patrolling a grassland for Meadow Voles.
Eastern Coyote
The eastward expansion of the Coyote (Canis latrans), a species of western North America’s grasslands and scrublands, and its progressive mixing with the Wolf (Canis lupus) in these eastern extensions of its range, has produced an expanding population of very adaptable generalists we call Eastern Coyotes (Canis latrans var.).  These omnivorous canines colonized the Lower Susquehanna River Watershed during the last four decades to replace extirpated wolves as the top-tier natural predator in the region.  Their primary diet includes Meadow Voles in grasslands and other small mammals along woodland edges and in successional habitats.  Seasonally, they consume the berries of numerous wild plants.  Slightly larger than their western ancestors, Eastern Coyotes with the admixture of Wolf genetics can subdue small ungulates.  Like other apex predators, they are attracted to vulnerable prey and thus play a crucial role in culling the weak and diseased among their potential quarry species to assure the health and potential of populations of these species as long-term sources of food energy.  The benefit to the prey species is however largely diluted in populous areas of the northeast; most venison consumed by Eastern Coyotes here is in the form of road kill.  During periods of extended snow cover when small rodents and other foods become inaccessible, Eastern Coyotes, particularly young individuals, will wander into new areas seeking sustenance.  Sometimes they venture into cities and suburbs where they explore the neighborhoods in search of garbage and pet foods placed outside the home.  (Video clip courtesy of Tyler and Grace Good. Click image to view.)

Wildlife certainly has a tough time making it through the winter in the lower Susquehanna valley.  Establishing and/or protecting habitat that includes plenty of year-round cover and sources of food and water can really give generalist species a better chance of survival.  But remember, the goal isn’t to create unnatural concentrations of wildlife, it is instead to return the landscape surrounding us into more of a natural state.  That’s why we try to use native plants as much as possible.  And that’s why we try to attract not only a certain bird, mammal, or other creature, but we try to promote the development of a naturally functioning ecosystem with a food web, a diversity of pollinating plants, pollinating insects, and so on.  Through this experience, we stand a better chance of understanding what it takes to graduate to the bigger job at hand—protecting, enhancing, and restoring habitats needed by specialist species.  These are efforts worthy of the great resources that are sometimes needed to make them a success.  It takes a mindset that goes beyond a focus upon the welfare of each individual animal to instead achieve the discipline to concentrate long-term on the projects and processes necessary to promote the health of the ecosystems within which specialist species live and breed.  It sounds easier than it is—the majority of us frequently become distracted.

Eastern Gray Squirrel
Being an individual from a population of a very successful generalist species is no guarantee of survival.  This Eastern Gray Squirrel fell from a tall tree when the limbs became ice covered during a storm earlier this month.  Just a freak accident?  Maybe, but mistakes like this are often fatal in the natural world.  This squirrel’s passing may seem brutal, but it provides a better opportunity for other squirrels and animals that share its food and cover requirements to make it through the winter.  And those survivors that didn’t suffer such a fatal mistake or, more importantly, don’t possess a vulnerability that may have contributed to such a mishap will have a chance to pass those traits on to a new generation.  This squirrel as an individual is gone, its species lives on, and may be stronger for its passing.
Prescribed Burn of a Grassland
Pennsylvania Game Commission crews maintain a grassland ecosystem for Short-eared Owls and other specialists using prescribed fire to prevent succession beyond its earliest stages.  Among the additional specialist species benefiting from this management tool are Monarchs and other butterflies whose host plants survive early-season fire, but not competition with woody vines, shrubs, trees, and invasive herbaceous growth.

On the wider scale, it’s of great importance to identify and protect the existing and potential future habitats necessary for the survival of specialist species.  And we’re not saying that solely for their benefit.  These protection measures should probably include setting aside areas on higher ground that may become the beach intertidal zone or tidal marsh when the existing ones become inundated.  And it may mean finally getting out of the wetlands, floodplains, and gullies to let them be the rain-absorbing, storm-buffering, water purifiers they spent millennia becoming.  And it may mean it’s time to give up on building stick structures on tinderbox lands, especially hillsides and rocky outcrops with shallow, eroding soils that dry to dust every few years.  We need to think ahead and stop living for the view.  If you want to enjoy the view from these places, go visit and take plenty of pictures, or a video, that’s always nice—then live somewhere else.  Each of these areas includes ecosystems that meet the narrow habitat requirements of many of our specialist species, and we’re building like fools in them.  Then we feign victimhood and solicit pity when the calamity strikes: fires, floods, landslides, and washouts—again and again.  Wouldn’t it be a whole lot smarter to build somewhere else?  It may seem like a lot to do for some specialist animals, but it’s not.  Because, you see, we should and can live somewhere else—they can’t.

The Allegheny Woodrat (Neotoma magister), a threatened species in Pennsylvania and a critically imperiled species in Maryland, is a habitat specialist requiring the forested rocky slopes, talus-flanked ridgetops, and caves of the Ridge and Valley Province for its nest sites and survival.  Isolated populations survived within similar environs in the lower Susquehanna River valley’s Piedmont Province and on South Mountain through at least the first half of the twentieth century, but have since been extirpated.  Human encroachment that fragments their habitat and promotes exposure to parasite-hosting mammals including the Raccoon (Procyon lotor), carrier of the Raccoon Roundworm (Baylisascarius procyonis), could prove fatal to remaining populations of this native mammal.  (National Park Service image by Rick Olsen)
American Oystercatcher
The American Oystercatcher (Haematopus palliatus) is a specialist species that uses its highly adapted bill to feed on marine invertebrates including mollusks, few of which are actually oysters.  Reliant upon tidal ecosystems for its survival, many of the seashore animals that make up this wader’s diet are themselves specialist species.  Oystercatchers spend nearly their entire lives in tidal marshes or within the intertidal zone on beaches.  They also frequent rocky jetties, particularly during high tide.  This individual was photographed near the mouth of Chesapeake Bay in Northhampton County, Virginia, a location that, when the waters of the Atlantic started rising over 10,000 years ago, was the lower Susquehanna valley about 60 miles from the river’s mouth at present-day Norfolk Canyon along the edge of the continental shelf.  Get the drift?

Photo of the Day

Red-eared Slider
Introduced species often exhibit greater vigor than the plants and animals that are indigenous to an ecosystem.  Today, we found this Red-eared Slider, a native of the lower Mississippi River basin, basking in the intermittent sunshine on the edge of a Susquehanna valley pond still partially covered with ice from the deep freeze earlier this month.  These turtles do not hibernate but instead brumate, remaining motionless on the bottom of the pond or under adjacent embankments.  During brumation, they eat nothing, but will come to the surface to bask on warm winter days.  This ability to be a “light sleeper” gives the invasive Red-eared Slider an advantage over the native turtles in our ponds, lakes, and rivers.  When spring finally does arrive, they’ll be the first to emerge and begin feeding, gaining the vitality they’ll need to start mating and depositing eggs before the local species.  Red-eared Sliders were released into the waters of the Lower Susquehanna River Watershed as unwanted pets and are now freely reproducing.  Their growing numbers are displacing some of our native species including several of our uncommon and rare turtles.

A Prescribed Fire Site After the Burn

Back on March 24th, we took a detailed look at the process involved in administering prescribed fire as a tool for managing grassland and early successional habitat.  Today we’re going turn back the hands of time to give you a glimpse of how the treated site fared during the five months since the controlled burn.  Let’s go back to Middle Creek Wildlife Management Area for a photo tour to see how things have come along…

Prescribed Fire application in March
Pennsylvania Game Commission crews administering prescribed fire on a grassland demonstration site back on March 16.
Prescribed Fire Site in May
By late May, native herbaceous perennial wildflowers including Joe-pye Weed had re-greened the site.  One of the goals of the burn was to kill fire-sensitive woody plants, thus preventing the process of succession from reforesting the site.
Prescribed Fire Site in May
The scorched, lifeless remains of small trees and shrubs indicate that that goal was met.
Yellow-breasted Chat in May
Because prescribed fire is administered in a mosaic pattern that permits some early successional growth to remain until the next burn, birds including this thicket-nesting Yellow-breasted Chat are able to take advantage of the mixed habitat during their breeding season in May and June.
Prescribed Fire Site in August
By August, the site is a haven for native plants and animals.
Native Warm-season Grasses and Wildlflowers in August
The burn has promoted the growth and late-summer bloom of fire-tolerant native wildflowers and warm-season grasses…
Indiangrass in Flower
…including Indiangrass,…
Big Bluestem
…Big Bluestem…
Thin-leaved Coneflower, a plant also known as Brown-eyed Susan.
…Thin-leaved Coneflower (Rudbeckia triloba), a plant also known as Brown-eyed Susan,…
Joe-pye Weed
…and Joe-pye Weed, a plant butterflies find irresistible.
Eastern Tiger Swallowtail collecting nectar from Joe-pye Weed.
Eastern Tiger Swallowtail collecting nectar from Joe-pye Weed.
Black-morph Eastern Tiger Swallowtail
A black-morph Eastern Tiger Swallowtail collecting nectar from Spotted Knapweed (Centaurea steobe micranthos), a non-native invasive plant found growing in an area of the burn site missed by this year’s fire.  While many non-native plants are unable to survive the flames and heat produced by prescribed fire, it isn’t an absolute cure-all.  It doesn’t eliminate all invasive plants, it just keeps them from dominating a landscape by out-competing native species.  Left unmanaged, Spotted Knapweed is a tough perennial invasive that can easily become one the species able to overtake a vulnerable grassland.  It can be a stubborn survivor of some prescribed burns.  On the plus side, butterflies really like it.
American Goldfinch
By August, native grassland plants in the prescribed fire area were already providing an abundance of seeds for birds including this American Goldfinch.
Carolina Grasshopper
For larger birds like turkeys and pheasants, an abundance of Carolina Grasshoppers are providing a protein-dense food source in managed grasslands.
Black Saddlebags
And tiny flying insects, a nuisance to us as we take a stroll alongside the grasslands, are a meal taken on the wing by dragonflies including this Black Saddlebags.

Elsewhere around the refuge at Middle Creek, prescribed fire and other management techniques are providing high-quality grassland habitat for numerous species of nesting birds…

Bobolink
Bobolinks nested both in areas subjected to controlled burns…
Bobolink in Hay Field
…and in hay fields where mowing was delayed until the nesting season, including the fledging process, was completed earlier this month.
Grasshopper Sparrow
As advertised, Grasshopper Sparrows nested in these fields as well.

We hope you enjoyed this short photo tour of grassland management practices.  Now, we’d like to leave you with one last set of pictures—a set you may find as interesting as we found them.  Each is of a different Eastern Cottontail, a species we found to be particularly common on prescribed fire sites when we took these images in late May.  The first two are of the individuals we happened to be able to photograph in areas subjected to fire two months earlier in March.  The latter two are of cottontails we happened to photograph elsewhere on the refuge in areas not in proximity to ground treated with a prescribed burn or exposed to accidental fire in recent years.

Eastern Cottontail
Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.
Eastern Cottontail
Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.

These first two rabbits are living the good life in a warm-season grass wonderland.

Eastern Cottontail with ticks.
Eastern Cottontail at a site not subjected to any recent fire activity.
Eastern Cottontail with ticks.
Eastern Cottontail at a site not subjected to any recent fire activity.

Oh Deer!  Oh Deer!  These last two rabbits have no clock to track the time; they have only ticks.  Better not go for a stroll with them Alice—that’s no wonderland!  I know, I know, it’s time to go.  See ya later.

Aphrodite Fritillary

The Aphrodite Fritillary (Speyeria aphrodite), also known simply as the Aphrodite, is a brush-footed butterfly of deciduous, coniferous, and mixed forests.  We found this female in a grassland margin between woodlots where prescribed fire was administered during the autumn of 2022 to reduce accumulations of natural fuels and an overabundance of invasive vegetation.  A goal of the burn was to promote the growth of native species including the violets (Viola species) favored as larval host plants by this and other fritillaries.

Aphrodite Fritillary
A female Aphrodite Fritillary collecting nectar from a thistle flower.

By the time these adult butterflies make their reproductive flights in late summer, the violets that serve as larval host plants have gone dormant.  To find patches of ground where the violets will come to life in spring, the female Aphrodite Fritillary has an ability to sense the presence of dormant roots, probably by smell.  Upon finding an area where suitable violets will begin greening up next year, she’ll deposit her eggs.  The eggs overwinter, then hatch to feed on the tender new violet leaves of spring.

Aphrodite Fritillary
A female Aphrodite Fritillary.  A prescribed burn, when administered during spring to manage fritillary habitat, is applied only to a portion of the land parcel each year to avoid decimating an entire population of the larvae during the first instar of their life cycle, a time when they are vulnerable to fire.
Aphrodite Fritillary
Our female Aphrodite Fritillary busily gathers nutritious nectar to provide sufficient energy for the critical process of mating and egg production.  What’s the thistle that this goddess of love and procreation is pollinating?…It’s a non-native invasive, the Bull Thistle (Cirsium vulgare), a species that readily colonizes new areas by producing an abundance of airborne seeds.  Continued management of this site with periodic applications of prescribed fire will prevent Bull Thistle and other invasives from overtaking the habitat during coming years.

Allegheny Vine

Here’s a native plant you don’t see very often, but Ruby-throated Hummingbirds have a knack for finding and adoring it within the limited habitat where it still exists.

Allegheny Vine in Bloom
Allegheny Vine (Adlumia fungosa), also known as Climbing Fumitory or Mountain Fringe, is a seldom-found biennial herbaceous plant in the poppy family (Papaveraceae).  Both its divided leaves and drooping clusters of flowers might remind the observer of a more familiar member of the poppy family, the spring-blooming Dutchman’s Breeches.  But unlike the low-growing Dutchman’s Breeches, Allegheny Vine ascends nearby shrubs and small trees with trailing stems that add a garland-like pizzazz to the summertime foliage.
Ruby-throated Hummingbird at Allegheny Vine
Seen here creeping atop a small Sassafras (Sassafras albidum) tree, Allegheny Vine seldom escapes notice by the Ruby-throated Hummingbird, a primary pollinator of the plant.
Ruby-throated Hummingbird at Allegheny Vine
Allegheny Vine grows on moist, rocky slopes and blooms in late summer, just in time to refuel migrating Ruby-throated Hummingbirds.

Not likely to thrive in deep forest cover, Allegheny Vine is a denizen of edge habitat.  The species is dependent on some type of disturbance to maintain suitable growing conditions.  The plants seen here were found flowering in an area that had experienced a fire prior to last year’s growing season.  It is therefore quite possible that the fire completed the stratification process and triggered long-dormant seeds to germinate last spring or summer to develop a basal plant which matured and flowered during this second summer of the biennial’s growth.  On a forested slope opposite this site, a first-ever prescribed burn was conducted in March of this year to eliminate accumulated fuel and replicate a natural fire cycle.  With a little luck, this forest management approach may prompt additional long-dormant Allegheny Vine seeds to germinate and form basal plants this year for maturation in 2025.  Without man-made disturbances, Allegheny Vine may remain viable as a species by enduring seed dormancy periods of 40-100 years or more between fires, lightning strikes, wind storms, ice accumulations, and other events which clear the canopy and encourage growth.

Ruby-throated Hummingbird at Allegheny Vine
Many years in the making, Allegheny Vine nectar must be delectable because the hummers can’t leave it alone.  And another plus, with a little help from prescribed fire, this native creeping plant seems to be holding its own while in direct competition with invasive Mile-a-minute Weed (leaves in lower right).

Photo of the Day

Similar in appearance to the invasive Brown Marmorated Stink Bug, the Western Conifer Seed Bug (Leptoglossus occidentalis) is a seldom-noticed denizen of pines.  During the 1950s, their range started expanding from the American west into the eastern states.  Like the stink bug, the Western Conifer Seed Bug emits a buzzing sound in flight and is capable of releasing a nasty-smelling compound from scent glands when harassed.  They feed on sap from developing pine cones, often causing deformities to the seeds, but posing no real harm to the trees.  The Western Conifer Seed Bug causes greatest consternation during the fall when, like the invasive stink bugs, it gathers in numbers and attempts to enter homes to spend the winter.  Those that get inside are mostly just an annoyance, but there have been reports of plumbing leaks caused by individual insects piercing PEX plastic water tubing with their mouths.

Colonies at War

Where does all the time go?  Already in 2024, half the calendar is in the trash and the gasoline and gunpowder gang’s biggest holiday of the year is upon us.  Instead of bringing you the memory-making odors of quick-burning sulfur or the noise and multi-faceted irritations that revved-up combustion engines bring, we thought it best to provide our readers with a taste of history for this Fourth of July.  Join us, won’t you, for a look back at one of the many events that shaped the landscape of our present-day world.


The early morning’s sun had just begun bathing the verdant gardens of the olde towne centre with a warm glowing light.  Birds were singing and the local folk were beginning to stir in preparation for their day’s chores.  Then, suddenly, something was stirring afoot.

The great battle had commenced.  Within minutes, thousands of colonists spilled onto the pavement to join the melee and defend their homes.

There’s no towne crier spreading the word on horseback.  Sensing aggression from a neighboring colony, a worker Pavement Ant (Tetramorium immigrans) functioning as a sentry issues the alert.  The aroma of pheromones produced by the sentry warns of danger and calls other workers to drop what their doing and instead respond to defend the nest.
Pavement Ants Join the Fray
Engaged in a dispute over territory, two colonies of Pavement Ants clash.  Though native to Europe, there is no evidence of Napoleonic tactics in their warfare.  All maneuver seems to be by chance.
Two Colonies of Pavement Ants in Battle
The workers doing the fighting are the sterile daughters of the one queen in each colony.  In addition to defending the nest, they do all the foraging and care for the queen’s eggs and young.  The young in each nest are its workers’ sisters and will include one or more new fertile queens.  These new queens, along with fertile males (brothers of the workers), develop wings and fly away to mate.  After mating, a young queen begins a new colony, excavating her own nest wherein she raises a first brood of workers to tend her forthcoming generation of eggs and young.  As the new colony grows, the queen’s workers expand the size of the underground nest by carrying particles of soil to the surface, depositing them around the entrance as telltale mounds.
Male Pavement Ant Amid Fighting Workers.
A winged male Pavement Ant gets caught in the fury of combat.  His primary role in life is to make a nuptial flight and mate with a queen to start a new colony.

The fighting was at close quarters—face to face with dominant soldiers sparing no effort to prevail in the struggle.

Pavement Ants in Combat
Worker Pavement Ants, all females, assume the role of soldiers to defend their nest, their colony, and their queen.

After about an hour had passed, the tide had turned and the fighting mass drifted to the south of the battle’s starting point.  The aggressors had been repelled.  The dispute was resolved—at least for a little while.

Pavement Ants in Battle
Thousands of Pavement Ants at the high-water mark of their desperate struggle.  It was a fierce, jaw-to-jaw contest to tear one’s opponent to pieces.
Pavement Ant Casualty
A winged Pavement Ant, probably a male and not a queen, falls victim to the fighting (upper right).  This casualty will not take part in a nuptial flight and will not contribute its colony’s DNA to a new population of ants.
Aggressive Pavement Ants Repelled
The tide turns and the invaders from the south are pushed back in the direction from whence they came.  Within minutes, the soldiers transitioned back to being workers.  No visual signs of the fight remained; casualties were carried away.

It wasn’t a struggle for independence.  And it wasn’t a fight for liberty.  For the sterile Pavement Ant worker, all the exertion and all the hazard of assuming the role of a soldier had but one purpose—to raise her sisters and become an aunt.  Long live the queen.

Photo of the Day

Paulownia in Flower
While in flower, this extensive stand of Princess Trees (Paulownia tomentosa) straddling Second Mountain north of Harrisburg might be mistaken for a series of boulder outcrops.  Native to eastern Asia, the fast-growing Princess Tree has escaped cultivation to become naturalized in many parts of eastern North America.  You’ll currently notice the showy purple blooms on many forested ridges and hilltops throughout the Lower Susquehanna River Watershed.  Paulownia tomentosa is also known as the Phoenix Tree, a name derived from its ability, due to its extensive root system, to regenerate following fire.  This fast-growing invasive therefore calls for measures in addition to prescribed burns for control within infected forests.  Mechanical and/or chemical methods of removal are frequently required.

Birds of the Sunny Grasslands

With the earth at perihelion (its closest approach to the sun) and with our home star just 27 degrees above the horizon at midday, bright low-angle light offered the perfect opportunity for doing some wildlife photography today.  We visited a couple of grasslands managed by the Pennsylvania Game Commission to see what we could find…

Grasslands and Hedgerows
On this State Game Lands parcel, prescribed fire is used to maintain a mix of grasslands and brushy early successional growth.  In nearby areas, both controlled fire and mechanical cutting are used to remove invasive species from hedgerows and the understory of woodlots.  Fire tolerant native species then have an opportunity to recolonize the forest and improve wildlife habitat.  This management method also reduces the fuel load in areas with the potential for uncontrolled wildfires.
The sun-dried fruits of a Common Persimmon tree found growing in a hedgerow.
The sun-dried fruits of a native Common Persimmon tree found growing in a hedgerow.
Savanna-like Grasslands
Just one year ago, mechanical removal of invasive trees and shrubs (including Multiflora Rose) on this State Game Land was followed by a prescribed fire to create this savanna-like grassland.
Song Sparrow
Hundreds of Song Sparrows were found in the grasses and thickets at both locations.
White-throated Sparrow
White-throated Sparrows were also abundant, but prefer the tangles and shrubs of the thickets.
Northern Mockingbird
Northern Mockingbirds were vigilantly guarding winter supplies of berries in the woodlots and hedgerows.
Swamp Sparrow
In grasses and tangles on wetter ground, about a dozen Swamp Sparrows were discovered.
White-crowned Sparrow
The adult White-crowned Sparrow is always a welcome find.
White-crowned Sparrow
And seeing plenty of juvenile White-crowned Sparrows provides some assurance that there will be a steady stream of handsome adult birds arriving to spend the winter during the years to come.
Dark-eyed Junco
Dark-eyed Juncos were encountered only in the vicinity of trees and large shrubs.
Savannah Sparrow
Several Savannah Sparrows were observed.  Though they’re mostly found in treeless country, this particular one happened to pose atop a clump of shrubs located within, you guessed it, the new savanna-like grasslands.
Winter Wren
A tiny bird, even when compared to a sparrow, the Winter Wren often provides the observer with just a brief glimpse before darting away into the cover of a thicket.
Standing Clump of Timber
Within grasslands, scattered stands of live and dead timber can provide valuable habitat for many species of animals.
A "snag" with an excavated nest cavity.
Woodpeckers and other cavity-nesting birds rely upon an abundance of “snags” (standing dead trees) for breeding sites.
Red-bellied Woodpecker
This Red-bellied Woodpecker and about a dozen others were found in trees left standing in the project areas.
Yellow-bellied Sapsucker
A Yellow-bellied Sapsucker soaks up some sun.
Pileated Woodpecker
This very cooperative Pileated Woodpecker seemed to be preoccupied by insect activity on the sun-drenched bark of the trees.  This denizen of mature forests will oft times wander into open country where larger lumber is left intact.

Pileated Woodpecker

Northern Harrier
Just as things were really getting fun, some late afternoon clouds arrived to dim the already fading daylight.  Just then, this Northern Harrier made a couple of low passes in search of mice and voles hidden in the grasses.
Northern Harrier
It was a fitting end to a very short, but marvelously sunny, early winter day.

Shorebirds and More at Bombay Hook National Wildlife Refuge

Have you purchased your 2023-2024 Federal Duck Stamp?  Nearly every penny of the 25 dollars you spend for a duck stamp goes toward habitat acquisition and improvements for waterfowl and the hundreds of other animal species that use wetlands for breeding, feeding, and as migration stopover points.  Duck stamps aren’t just for hunters, purchasers get free admission to National Wildlife Refuges all over the United States.  So do something good for conservation—stop by your local post office and get your Federal Duck Stamp.

2023-2024 Federal Duck Stamp. Your Federal Duck Stamp is your free pass to visit the nation's National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.
Your Federal Duck Stamp is your admission ticket for entry into many of the country’s National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.

Still not convinced that a Federal Duck Stamp is worth the money?  Well then, follow along as we take a photo tour of Bombay Hook National Wildlife Refuge.  Numbers of southbound shorebirds are on the rise in the refuge’s saltwater marshes and freshwater pools, so we timed a visit earlier this week to coincide with a late-morning high tide.

Northern Bobwhite
This pair of Northern Bobwhite, a species now extirpated from the Lower Susquehanna River Watershed and the rest of Pennsylvania, escorted us into the refuge.  At Bombay Hook, they don’t waste your money mowing grass.  Instead, a mosaic of warm-season grasses and early successional growth creates ideal habitat for Northern Bobwhite and other wildlife.
Shearness Pool at Bombay Hook N.W.R.
Twice each day, high tide inundates mudflats in the saltwater tidal marshes at Bombay Hook prompting shorebirds to move into the four man-made freshwater pools.  Birds there can often be observed at close range.  The auto tour route through the refuge primarily follows a path atop the dikes that create these freshwater pools.  Morning light is best when viewing birds on the freshwater side of the road, late-afternoon light is best for observing birds on the tidal saltwater side.
Great Blue Heron
A Great Blue Heron at high tide on the edge of a tidal creek that borders Bombay Hook’s tour route at Raymond Pool.
Semipalmated Sandpipers
Semipalmated Sandpipers stream into Raymond Pool to escape the rising tide in the salt marsh.
Semipalmated Sandpipers and Short-billed Dowitcher
More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.
Short-billed Dowitchers
Two more Short-billed Dowitchers on the way in.
Sandpipers, Avocets, Egrets, and Mallards
Recent rains have flooded some of the mudflats in Bombay Hook’s freshwater pools. During our visit, birds were often clustered in areas where bare ground was exposed or where water was shallow enough to feed.  Here, Short-billed Dowitchers in the foreground wade in deeper water to probe the bottom while Semipalmated Sandpipers arrive to feed along the pool’s edge.  Mallards, American Avocets, and egrets are gathered on the shore.
Short-billed Dowitchers
More Short-billed Dowitchers arriving to feed in Raymond Pool.
Semipalmated Sandpipers
Hundreds of Semipalmated Sandpipers gathered in shallow water where mudflats are usually exposed during mid-summer in Raymond Pool.
Hundreds of Semipalmated Sandpipers, several Short-billed Dowitchers, and some Forster’s Terns (Sterna forsteri) crowd onto a mud bar at Bear Swamp Pool.
Semipalmated Sandpipers, Forster's Terns, and a Short-billed Dowitcher
A zoomed-in view of the previous image showing a tightly packed crowd of Semipalmated Sandpipers, Forster’s Terns, and a Short-billed Dowitcher (upper left).
Short-billed Dowitchers
Short-billed Dowitchers wading to feed in the unusually high waters of Raymond Pool.
Short-billed Dowitchers, American Avocets, and a Snowy Egret
Short-billed Dowitchers, American Avocets, and a Snowy Egret in Raymond Pool.  A single Stilt Sandpiper (Calidris himantopus) can been seen flying near the top of the flock of dowitchers just below the egret.
Stilt Sandpiper among Short-billed Dowitchers
Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.
American Avocets
American Avocets probe the muddy bottom of Raymond Pool.
Dunlin and Short-billed Dowitchers
Among these Short-billed Dowitchers, the second bird from the bottom is a Dunlin. This sandpiper, still in breeding plumage, is a little bit early.  Many migrating Dunlin linger at Bombay Hook into October and even November.
Least Sandpiper
This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool
Greater Yellowlegs
A Greater Yellowlegs at Bear Swamp Pool.
Caspian Tern
A Caspian Tern patrolling Raymond Pool.
Marsh Wren singing
The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.
Marsh Wren Nest
This dome-shaped Marsh Wren nest is supported by the stems of Saltwater Cordgrass (Sporobolus alterniflorus), a plant also known as Smooth Cordgrass.  High tide licks at the roots of the cordgrass supporting the temporary domicile.
Seaside Dragonlet
By far the most common dragonfly at Bombay Hook is the Seaside Dragonlet (Erythrodiplax berenice).  It is our only dragonfly able to breed in saltwater.  Seaside Dragonlets are in constant view along the impoundment dikes in the refuge.
Red-winged Blackbird
Red-winged Blackbirds are still nesting at Bombay Hook, probably tending a second brood.
Bobolink
Look up!   A migrating Bobolink passes over the dike at Shearness Pool.
Mute Swans and Canada Geese
Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.
Trumpeter Swans
A pair of Trumpeter Swans (Cygnus buccinator) as seen from the observation tower at Shearness Pool.  Unlike gregarious Tundra and Mute Swans, pairs of Trumpeter Swans prefer to nest alone, one pair to a pond, lake, or sluggish stretch of river.  The range of these enormous birds was restricted to western North America and their numbers were believed to be as low as 70 birds during the early twentieth century.  An isolated population consisting of several thousand birds was discovered in a remote area of Alaska during the 1930s allowing conservation practices to protect and restore their numbers.  Trumpeter Swans are slowly repopulating scattered east coast locations following recent re-introduction into suitable habitats in the Great Lakes region.
Great Egret
A Great Egret prowling Shearness Pool.
Snowy Egret
A Snowy Egret in Bear Swamp Pool.
A hen Wood Duck (second from right) escorts her young.
Wood Ducks in Bear Swamp Pool.
Black-necked Stilt and young.
A Bombay Hook N.W.R. specialty, a Black-necked Stilt and young at Bear Swamp Pool.

As the tide recedes, shorebirds leave the freshwater pools to begin feeding on the vast mudflats exposed within the saltwater marshes.  Most birds are far from view, but that won’t stop a dedicated observer from finding other spectacular creatures on the bay side of the tour route road.

Bombay Hook National Wildlife Refuge protects a vast parcel of tidal salt marsh and an extensive network of tidal creeks. These areas are not only essential wildlife habitat, but are critical components for maintaining water quality in Delaware Bay and the Atlantic.
Atlantic Horseshoe Crab
The shells of expired Atlantic Horseshoe Crabs were formerly widespread and common among the naturally occurring flotsam along the high tide line on Delaware Bay.  We found just this one during our visit to Bombay Hook.  Man has certainly decimated populations of this ancient crustacean during recent decades.
As the tide goes out, it’s a good time for a quick walk into the salt marsh on the boardwalk trail opposite Raymond Pool.
Atlantic Marsh Fiddler Crabs
Among the Saltmarsh Cordgrass along the trail and on the banks of the tidal creek there, a visitor will find thousands and thousands of Atlantic Marsh Fiddler Crabs (Minuca pugnax).
Atlantic Marsh Fiddler Crabs
Atlantic Marsh Fiddler Crabs and their extensive system of burrows help prevent the compaction of tidal soils and thus help maintain ideal conditions for the pure stands of Saltwater Cordgrass that trap sediments and sequester nutrients in coastal wetlands.
Atlantic Marsh Fiddler Crab
A male Atlantic Marsh Fiddler Crab peers from its den.
Great Egret
Herons and egrets including this Great Egret are quite fond of fiddler crabs.  As the tide goes out, many will venture away from the freshwater pools into the salt marshes to find them.
Green Heron
A Green Heron seen just before descending into the cordgrass to find fiddler crabs for dinner.
Clapper Rail
A juvenile Clapper Rail (Rallus crepitans crepitans) emerges from the cover of the cordgrass along a tidal creek to search for a meal.
Glossy Ibis
Glossy Ibis leave their high-tide hiding place in Shearness Pool to head out into the tidal marshes for the afternoon.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide in the marshes opposite Shearness Pool.
Ospey
An Osprey patrols the vast tidal areas opposite Shearness Pool.

No visit to Bombay Hook is complete without at least a quick loop through the upland habitats at the far end of the tour route.

Indigo Bunting
Indigo Buntings nest in areas of successional growth and yes, that is a Spotted Lanternfly on the grape vine at the far right side of the image.
Blue Grosbeak
Blue Grosbeaks (Passerina caerulea) are common nesting birds at Bombay Hook.  This one was in shrubby growth along the dike at the north end of Shearness Pool.
Trumpet Creeper and Poison Ivy
These two native vines are widespread at Bombay Hook and are an excellent source of food for birds. The orange flowers of the Trumpet Vine are a hummingbird favorite and the Poison Ivy provides berries for numerous species of wintering birds.
Pileated Woodpecker in Sweet Gum
The Pileated Woodpecker is one of the numerous birds that supplements its diet with Poison Ivy berries.  The tree this individual is visiting is an American Sweetgum (Liquidambar styraciflua), a species native to the Atlantic Coastal Plain in Delaware.  The seed balls are a favorite winter food of goldfinches and siskins.
Red-bellied Slider and Painted Turtle
Finis Pool has no frontage on the tidal marsh but is still worth a visit.  It lies along a spur road on the tour route and is located within a deciduous coastal plain forest.  Check the waters there for basking turtles like this giant Northern Red-bellied Cooter (Pseudemys rubiventris) and much smaller Painted Turtle.
White-tailed Deity
The White-tailed Deity is common along the road to Finis Pool.
Fowler's Toad
Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.
Turk's Cap Lily
The National Wildlife Refuge System not only protects animal species, it sustains rare and unusual plants as well.  This beauty is a Turk’s Cap Lily (Lilium superbum), a native wildflower of wet woods and swamps.
Wild Turkey
Just as quail led us into the refuge this morning, this Wild Turkey did us the courtesy of leading us to the way out in the afternoon.

We hope you’ve been convinced to visit Bombay Hook National Wildlife Refuge sometime soon.  And we hope too that you’ll help fund additional conservation acquisitions and improvements by visiting your local post office and buying a Federal Duck Stamp.

Photo of the Day

A Reforestation Project
Visible in the background of this image, an infestation of invasive Emerald Ash Borer larvae has killed the trees in a woodlot comprised exclusively of Green Ash.  Left standing, the dead snags provide excellent habitat for a number of animal species including cavity-nesting birds like woodpeckers, known consumers of these destructive larvae.  To reforest the mowed field in the foreground, a variety of native deciduous trees have been planted.  In areas where a diversity of trees are not present to furnish a source of seeds for natural succession, manually planting an array of seedlings provides some insurance against the risk of allowing establishment of a single pioneer species such as the vulnerable Green Ash.  The white plastic tubes on the young trees offer protection from the ever-browsing White-tailed Deity.

Purple Haze Across the Fields

Have you noticed a purple haze across the fields right now?  If so, you may have wondered, “What kind of flowers are they?”

A purple haze of color stretches across fields not already green with cold-season crops like winter wheat.

Say hello to Purple Dead Nettle (Lamium purpureum), a non-native invasive species that has increased its prevalence in recent years by finding an improved niche in no-till cropland.  Purple Dead Nettle, also known as Red Dead Nettle, is native to Asia and Europe.  It has been a familiar early spring “weed” in gardens, along roadsides, and in other disturbed ground for decades.

Purple Dead Nettle owes its new-found success to the timing of its compressed growing season.  Its tiny seeds germinate during the fall and winter, after crops have been harvested and herbicide application has ended for the season.  The plants flower early in the spring and are thus particularly attractive to Honey Bees and other pollinators looking for a source of energy-rich nectar as they ramp up activity after winter lock down.  In many cases, Purple Dead Nettle has already completed its flowering cycle and produced seeds before there is any activity in the field to prepare for planting the summer crop.  The seeds spend the warmer months in dormancy, avoiding the hazards of modern cultivation that expel most other species of native and non-native plants from the agricultural landscape.

Purple Dead Nettle in Bloom
Flowering Purple Dead Nettle as a volunteer cover crop among last year’s corn stubble in a no-till field.
Purple Dead Nettle
Like the flowers of orchids, Purple Hedge Nettle blossoms are described as yoke shaped or bilateral (zygomorphic).  Psychedelic experiences are produced only through observation, not by ingestion.  A member of the mint family, its edible young leaves and tops have nutritional value, making a unique addition to salads and soups.
Purple Dead Nettle, Common Dandelion, and Shepherd's Purse
We call them “weeds”, but what do we know?  Purple Dead Nettle, Common Dandelion, and Shepherd’s Purse (Capsella bursa-pastoris), three edible non-native invasive species with similar life cycles seen here flowering along a rural road among fields where intensive farming is practiced.  Shepard’s Purse, like many members of the mustard family, is already producing seeds at the bottom of the flower cluster by the time the uppermost buds open for business.
Spraying Herbicide
In preparation for seeding of a warm-season crop,  herbicide is applied on a no-till field to kill Shepherd’s Purse and other cool-season plants.  To help prevent sediment and nutrient discharge from lands where high-intensity agriculture is practiced, no-till methods are used to reduce runoff from the areas of bare soil that would otherwise be created by traditional plowing.

While modern farming has eliminated a majority of native plant and animal species from agricultural lands of the lower Susquehanna valley, its crop management practices have simultaneously invited vigorous invasion by a select few non-native species.   High-intensity farming devotes its acreage to providing food for a growing population of people—not to providing wildlife habitat.  That’s why it’s so important to minimize our impact on non-farm lands throughout the remainder of the watershed.  If we continue subdividing, paving, and mowing more and more space, we’ll eventually be living in a polluted semi-arid landscape populated by little else but non-native invasive plants and animals.  We can certainly do better than that.

Shakedown Cruise of the S. S. Haldeman

First there was the Nautilus.  Then there was the Seaview.  And who can forget the Yellow Submarine?  Well, now there’s the S. S. Haldeman, and today we celebrated her shakedown cruise and maiden voyage.  The Haldeman is powered by spent fuel that first saw light of day near Conewago Falls at a dismantled site that presently amounts to nothing more than an electrical substation.  Though antique in appearance, the vessel discharges few emissions, provided there aren’t any burps or hiccups while underway.  So, climb aboard as we take a cruise up the Susquehanna at periscope depth to have a quick look around!

Brunner Island as seen from the east channel.
Close-in approach to emergent Water Willow growing on an alluvial Island.
The approach to York Haven Dam and Conewago Falls from the west channel.
A pair of Powdered Dancers on a midriver log.

Watertight and working fine.  Let’s flood the tanks and have a peek at the benthos.  Dive, all dive!

American Eelgrass, also known as Tapegrass, looks to be growing well in the channels.  Historically, vast mats of this plant were the primary food source for the thousands of Canvasback ducks that once visited the lower Susquehanna each autumn.
As is Water Stargrass (Heteranthera dubia).  When mature, both of these native plants provide excellent cover for young fish.  Note the abundance of shells from deceased Asiatic Clams (Corbicula fluminea) covering the substrate.
Mayfly nymph
A three-tailed mayfly (Ephemeroptera) nymph and a several exoskeletons cling to the downstream side of a rock.
Comb-lipped Casemaker Caddisfly larva and case.
This hollowed-out stick may be a portable protective shelter belonging to a Comb-lipped Casemaker Caddisfly larva (Calamoceratidae).  The larva itself appears to be extending from the end of the “case” in the upper right of the image.  Heteroplectron americanum, a species known for such behavior, is a possibility. 
Rusty Crayfish
In the Susquehanna and its tributaries, the Rusty Crayfish (Faxonius rusticus) is an introduced invasive species.  It has little difficulty displacing native species due to its size and aggressiveness.
Rusty Crayfish
A Rusty Crayfish.
Freshwater Snails Susquehanna: Virginian River Horn Snail
Summers with conditions that promote eelgrass and stargrass growth tend to be big years for Virginian River Horn Snails (Elimia virginica).  2022 appears to be one of those years.  They’re abundant and they’re everywhere on the rocks and gravel substrate in midriver.  Feeding almost incessantly on algae and detritus, these snails are an essential component of the riverine ecosystem, breaking down organic matter for final decomposition by bacteria and fungi.
Freshwater Snails Susquehanna: Virginian River Horn Snail
Bits of debris suspended in the flowing water streak by this Virginian River Horn Snail.  The spire-shaped shell is a streamlining adaptation for maneuvering and holding fast in the strong current.
Freshwater Snails Susquehanna: Virginian River Horn Snail
A young Virginian River Horn Snail following a mature adult.  Note the green algae growing among the decaying plant and animal remains that blanket the river bottom.
Freshwater Snails Susquehanna: Virginian River Horn Snail
Two of a population that may presently include millions of Virginian River Horn Snails living downstream of Conewago Falls.
Susquehanna Snails: Virginian River Horn Snails and Lesser Mystery Snails
Virginian River Horn Snails with Lesser Mystery Snails (Campeloma decisum), another native species commonly encountered at Conewago Falls and in surrounding waters.
Freshwater Snails Susquehanna: River Snail and Virginian River Horn Snail
A River Snail (Leptoxis carinata), also known as a Crested Mudalia, hitching a ride on a Virginian River Horn Snail.  The two species are frequently found together.
Mollusks of the Susquehanna: Yellow Lampmussel and River Snail
A River Snail cleaning the shell of a native freshwater Unionidae mussel, Lampsilis cariosa, commonly called the Yellow Lampmussel or Carried Lampmussel.  Because of their general decline in abundance and range, all Unionidae mussels are protected in Pennsylvania.
Fishes of the Susquehanna: Banded Darter
The Banded Darter (Etheostoma zonale) is a member of the perch family (Percidae).
Fishes of the Susquehanna: Smallmouth Bass
A Smallmouth Bass in strong current.
Fishes of the Susquehanna: Spotfin or Satinfin Shiners
Along the edge of an alluvial island at midriver, Cyprinella (Spotfin or Satinfin) Shiners gather in the cover of an emergent stand of Water Willow.  The closely related Spotfin Shiner (Cyprinella spiloptera) and Satinfin Shiner (Cyprinella analostanus) are nearly impossible to differentiate in the field.
Fishes of the Susquehanna: Spotfin or Satinfin Shiner
A breeding condition male Cyprinella (Spotfin or Satinfin) Shiner.
Fishes of the Susquehanna; Juvenile Channel Catfish
A juvenile Channel Catfish.

We’re finding that a sonar “pinger” isn’t very useful while running in shallow water.  Instead, we should consider bringing along a set of Pings—for the more than a dozen golf balls seen on the river bottom.  It appears they’ve been here for a while, having rolled in from the links upstream during the floods.  Interestingly, several aquatic species were making use of them.

River Snail cleaning a golf ball.
River Snail cleaning a golf ball.
Net-spinning Caddisfly (Hydropsychidae)
A golf ball used as an anchor point for silk cases woven by Net-spinning Caddisfly (Hydropsychidae) larvae to snare food from the water column.
Freshwater Snails (Gastropods) of the Lower Susquehanna River Watershed: Creeping Ancylid (Ferrissia species)
A Creeping Ancylid (Ferrissia species), a tiny gastropod also known as a Coolie Hat Snail, River Limpet, or Brook Freshwater Limpet, inhabits the dimple on a “Top Flight”.
Freshwater Snails (Gastropods) of the Lower Susquehanna River Watershed: Creeping Ancylid (Ferrissia species)
A closeup view of the Creeping Ancylid.  The shell sits atop the snail’s body like a helmet.
We now know why your golf balls always end up in the drink, it’s where they go to have their young.

Well, it looks like the skipper’s tired and grumpy, so that’s all for now.  Until next time, bon voyage!

Monarch an Endangered Species: What You Can Do Right Now

This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered.  Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.

Monarch on Common Milkweed Flower Cluster
A recently arrived Monarch visits a cluster of fragrant Common Milkweed flowers in the garden at the susquehannawildlife.net headquarters.  Milkweeds included among a wide variety of plants in a garden or meadow habitat can help local populations of Monarchs increase their numbers before the autumn flights to wintering grounds commence in the fall.  Female Monarchs lay their eggs on milkweed leaves, then, after hatching, the larvae (caterpillars) feed on them before pupating.

If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow.  In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.

Comparison of Mowed Grass to Wildflower Meadow
* Particularly when native warm-season grasses are included (root depth 6′-8′)

Still not ready to take the leap.  Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides.  There’ll be no pesticide residues leaching into the soil or running off during downpours.  Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply.  Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground.  Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.

What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space?  That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream.  All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden.  Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs.  Look what we get for pennies a plant…

Wildflower Garden
Some of the wildflowers and warm-season grasses grown from scattered seed in the susquehannawildlife.net headquarters garden.

Here’s a closer look…

Lance-leaved Coreopsis
Lance-leaved Coreopsis (Coreopsis lanceolata), a perennial.
Black-eyed Susan
Black-eyed Susan, a biennial or short-lived perennial.
Black-eyed Susan "Gloriosa Daisy"
“Gloriosa Daisy”, a variety of Black-eyed Susan, a biennial or short-lived perennial.
Purple Coneflower
Purple Coneflower, an excellent perennial for pollinators.  The ripe seeds provide food for American Goldfinches.
Common Sunflower
A short variety of Common Sunflower, an annual and a source of free bird seed.
Common Sunflower
Another short variety of Common Sunflower, an annual.

All this and best of all, we never need to mow.

Around the garden, we’ve used a northeast wildflower mix from American Meadows.  It’s a blend of annuals and perennials that’s easy to grow.  On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden.  They even have a mix specifically formulated for hummingbirds and butterflies.

Annuals in bloom
When planted in spring and early summer, annuals included in a wildflower mix will provide vibrant color during the first year.  Many varieties will self-seed to supplement the display provided by biennials and perennials in subsequent years.
Wildflower Seed Mix
A northeast wildflower mix from American Meadows.  There are no fillers.  One pound of pure live seed easily plants 1,000 square feet.

Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing.  One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property.  A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.

For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania.  Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime.  They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses.  Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds

      • Pipeline Mixes
      • Pasture, Grazing, and Hay Mixes
      • Cover Crops
      • Pondside Mixes
      • Warm-season Grass Mixes
      • Retention Basin Mixes
      • Wildlife Mixes
      • Pollinator Mixes
      • Wetland Mixes
      • Floodplain and Riparian Buffer Mixes
      • Rain Garden Mixes
      • Steep Slope Mixes
      • Solar Farm Mixes
      • Strip Mine Reclamation Mixes

We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success.  For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”.  It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends.  More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.

Swamp Milkweed
Swamp Milkweed, a perennial species, is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”.  It is a favorite of female Monarchs seeking a location to deposit eggs.
Monarch Caterpillar feeding on Swamp Milkweed
A Monarch larva (caterpillar) feeding on Swamp Milkweed.
Butterfly Weed
Butterfly Weed (Asclepias tuberosa) is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”.  This perennial is also known as Butterfly Milkweed.
Tiger Swallowtails visiting Butterfly Weed
Eastern Tiger Swallowtails are among the dozens of species of pollinators that will visit Butterfly Weed.

In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.

Wild Bergamot
The perennial Wild Bergamot, also known as Bee Balm, is an excellent pollinator plant, and the tubular flowers are a favorite of hummingbirds.
Oxeye
Oxeye is adorned with showy clusters of sunflower-like blooms in mid-summer.  It is a perennial plant.
Plains Coreopsis
Plains Coreopsis (Coreopsis tinctoria), also known as Plains Tickseed, is a versatile annual that can survive occasional flooding as well as drought.
Gray-headed Coneflower
Gray-headed Coneflower (Ratibida pinnata), a tall perennial, is spectacular during its long flowering season.
Monarch on goldenrod.
Goldenrods are a favorite nectar plant for migrating Monarchs in autumn.  They seldom need to be sown into a wildflower garden; the seeds of local species usually arrive on the wind.  They are included in the “Butterfly and Hummingbird Garden Mix” from Ernst Conservation Seeds in low dose, just in case the wind doesn’t bring anything your way.
Partridge Pea
Is something missing from your seed mix?  You can purchase individual species from the selections available at American Meadows and Ernst Conservation Seeds.  Partridge Pea is a good native annual to add.  It is a host plant for the Cloudless Sulphur butterfly and hummingbirds will often visit the flowers.  It does really well in sandy soils.
Indiangrass in flower.
Indiangrass is a warm-season species that makes a great addition to any wildflower meadow mix.  Its deep roots make it resistant to drought and ideal for preventing erosion.

Why not give the Monarchs and other wildlife living around you a little help?  Plant a wildflower garden or meadow.  It’s so easy, a child can do it.

Planting a riparian buffer with wildflowers and warm-season grasses
Volunteers sow a riparian buffer on a recontoured stream bank using wildflower and warm-season grass seed blended uniformly with sand.  By casting the sand/seed mixture evenly over the planting site, participants can visually assure that seed has been distributed according to the space calculations.
Riparian Buffer of wildflowers
The same seeded site less than four months later.
Monarch Pupa
A Monarch pupa from which the adult butterfly will emerge.

Photo of the Day

Mollusks of the Lower Susquehanna River Watershed: Gray Garden Slug
The Gray Garden Slug (Deroceras reticulatum) is an invasive inhabitant of places subjected to human disturbance, especially cultivated farmland and, as the common name suggests, gardens.  They are most active at night, hiding beneath plant litter, trash, and rocks during the daytime.  This inch-long specimen was photographed while out and about on a recent dreary and damp afternoon.  Natural enemies of terrestrial slugs include birds, toads, frogs, snakes, and some beetles in the family Caribidae.  In the field and vegetable patch, keeping leaf litter and other debris away from the base of young plants can reduce damage caused by these hungry mollusks.

Times Are Tough

Rising prices, an exhausted workforce, political polarization, and pandemic fatigue—times are tough.  Product shortages have the consumer culture in a near panic.  Some say the future just isn’t what it used to be.

Well, Uncle Tyler Dyer reminds us that things could be worse.  He shares with us this observation, “Man, as long as people are spending money poisoning the weeds on their lawns instead of eating them, things aren’t that bad.”

Uncle Ty is particularly fond of the Common Dandelion (Taraxacum officinale), “Check it out.  Roasted dandelion roots can make a coffee substitute, the blossoms a wine, and the leaves used to create my favorites, nutrient-dense salads or green vegetable dishes.”

The Common Dandelion is despised by many as a “weed”.  To others it is a beautiful flowering plant that happens to be quite edible.  Native to Europe and Asia, North American varieties of Common Dandelion are an escape from cultivation, originally imported as a food crop.  Uncle Ty’s great-grandparents never would have dreamed of killing them with herbicides instead of harvesting them.
Uncle Ty Dyer’s lunch, fresh dandelion greens and hot bacon dressing.

So have a homegrown salad and remember, maybe things aren’t that bad after all.

Conowingo Dam: Cormorants, Eagles, Snakeheads and a Run of Hickory Shad

Meet the Double-crested Cormorant,  a strangely handsome bird with a special talent for catching fish.  You see, cormorants are superb swimmers when under water—using their webbed feet to propel and maneuver themselves with exceptional speed in pursuit of prey.

Like many species of birds that dive for their food, Double-crested Cormorants run across the surface of the water to gain speed for a takeoff.  Smaller wings may make it more difficult to get airborne, but when folded, they provide improved streamlining for submerged swimming.

Double-crested Cormorants, hundreds of them, are presently gathered along with several other species of piscivorous (fish-eating) birds on the lower Susquehanna River below Conowingo Dam near Rising Sun, Maryland.  Fish are coming up the river and these birds are taking advantage of their concentrations on the downstream side of the impoundment to provide food to fuel their migration or, in some cases, to feed their young.

Double-crested Cormorants, mostly adult birds migrating toward breeding grounds to the north, are gathered on the rocks on the east side of the river channel below Conowingo Dam.  A Great Blue Heron from a nearby rookery can be seen at the center of the image.
Bald Eagles normally gather in large numbers at Conowingo Dam in the late fall and early winter.  Presently there are more than 50 there, and the majority of them are breeding age adults.  Presumably they are still on their way north to nest.  Meanwhile, local pairs are already feeding young, so it seems these transient birds are running a bit late.  Many of them can be seen on the rocks along the east side of the river channel,…
…on the powerline trestles on the island below the dam…
…in the trees along the east shore,…
…and in the trees surrounding Fisherman’s Park on the west shore.

In addition to the birds, the movements of fish attract larger fish, and even larger fishermen.

Anglers gather to fish the placid waters below the dam’s hydroelectric powerhouse .  Only a few of the generating turbines are operating, so the flow through the dam is minimal.
Some water is being released along the west shoreline to attract migratory river herring to the west fish lift for sorting and retention as breeding stock for a propagation program.  The east lift, the passage that hoists American Shad (Alosa sapidissima) to a trough that allows them to swim over the top of the dam to waters upriver, will begin operating as soon as these larger migratory fish begin arriving.

The excitement starts when the sirens start to wail and the red lights begin flashing.  Yes friends, it’s showtime.

Red lights and sirens are a warning that additional flow is about to be released from the dam.  Boaters should anticipate rough water and persons in and along the river need to seek higher ground immediately.
Gates are opened at mid-river to release a surge of water through the dam.
The wake from the release quickly reaches the shoreline, raising the water level in moments.
Experienced anglers know that the flow through the dam gets fish moving and can improve the catch significantly, especially in spring when many species are ascending the river.

Within minutes of the renewed flow, birds are catching fish.

A Double-crested Cormorant with a young Channel Catfish (Ictalurus punctatus).
A Double-crested Cormorant fleeing others trying to steal its Channel Catfish.
Another Double-crested Cormorant eating a Channel Catfish.  Did you realize that Channel Catfish were an introduced species in the Susquehanna River system?
An Osprey with a stick, it’s too busy building a nest right now to fish.
Great Blue Herons swallow their prey at the spot of capture, then fly back to the nest to regurgitate a sort of “minced congealed fish product” to their young.

Then the anglers along the wave-washed shoreline began catching fish too.

This young man led off a flurry of catches that would last for the remainder of the afternoon.
Though Gizzard Shad are filter feeders that don’t readily take baits and lures, they are regularly foul-hooked and reeled in from the large schools that ascend the river in spring.
Gizzard Shad are very abundant in the lower Susquehanna, providing year-round forage for many species of predatory animals including Bald Eagles.
A Double-crested Cormorant swallowing a Gizzard Shad.
This angler soon helped another fisherman by landing his large catch, a Northern Snakehead (Channa argus).
The teeth of a Northern Snakehead are razor sharp.  It is an aggressive non-native invasive species currently overtaking much of the Lower Susquehanna River Watershed.  Anglers are encouraged to fish for them, catch them, keep them, and kill them at the site of capture.  Never transport a live Northern Snakehead  anywhere at any time.  It is illegal in both Maryland and Pennsylvania to possess a live snakehead. 
Northern Snakehead advisory sign posted at Exelon Energy’s Conowingo Fishermen’s Park.
A stringer of Northern Snakeheads.  This species was imported from Asia as a food fish, so it has excellent culinary possibilities.  It’s better suited for a broiler or frying pan than a river or stream.
Another stringer of Northern Snakeheads.  It’s pretty safe to say that they have quickly become one of the most abundant predatory fish in the river.  Their impact on native species won’t be good, so catch and eat as many as you can.  Remember, snakeheads swim better in butter and garlic than in waters with native fish.
This foul-hooked Shorthead Redhorse (Moxostoma macrolepidotum), a native species of sucker, was promptly released.
Striped Bass are anadromous fish that leave the sea in spring to spawn in fresh water.  They ascend the Susquehanna in small numbers, relying upon the operation of the fish passages at the Conowingo, Holtwood, Safe Harbor, and York Haven Dams to continue their journey upstream.  During spring spawning, Striped Bass in the Susquehanna River and on the Susquehanna Flats portion of the upper Chesapeake Bay are not in season and may not be targeted, even for catch-and-release.  This accidental catch was immediately turned loose.
After removal from the hook, this hefty Smallmouth Bass was returned to the river.  Many anglers are surprised to learn that Smallmouth Bass are not native to the Susquehanna basin.
This angler’s creel contains a Northern Snakehead (left) and a Walleye (right).  Did you know that the Walleye (Sander vitreus) is an introduced species in the Susquehanna watershed?
By late afternoon, anglers using shad darts began hooking into migrating Hickory Shad (Alosa mediocris), a catch-and-release species in Maryland.
Hickory Shad are recognized by their lengthy lower jaw.  They are anadromous herring that leave the sea to spawn in freshwater streams.  Hickory Shad ascend the Susquehanna as far as Conowingo Dam each year, but shy away from the fish lifts.  Downriver from the dam, they do ascend Deer Creek along the river’s west shore and Octoraro Creek on the east side.  In Pennsylvania, the Hickory Shad is an endangered species.
A Hickory Shad angled on a dual shad dart rig.  During the spring spawning run, they feed mostly on small fish, and are the most likely of the Susquehanna’s herring to take the hook.
Simultaneous hook-ups became common after fours hours worth of release water from the dam worked its way toward the mouth of the river and got the schools moving.  Water temperatures in the mid-to-upper-fifties trigger the ascent of Hickory Shad.  On the Susquehanna, those temperatures were slow to materialize in the spring of 2021, so the Hickory Shad migration is a bit late.
Catch-and-release fishing for Hickory Shad appears to be in full swing not only at the dam, but along the downstream shoreline to at least the mouth of Deer Creek at Susquehanna State Park too.
Many Hickory Shad could be seen feeding on some of the millions of caddisflies (Trichoptera) swarming on the river.  These insects, along with earlier hatches of Winter Stoneflies (Taeniopterygidae), not only provide forage for many species of fish, but  are a vital source of natural food for birds that migrate up the river in March and April each year.  Swallows, Ring-billed Gulls, and Bonaparte’s Gulls are particularly fond of snatching them from the surface of the water.
A Winter Stonefly (Taeniopterygidae) from an early-season hatch on the Susquehanna River at the Veteran’s Memorial Bridge at Columbia/Wrightsville, Pennsylvania.  (March 3, 2021)
Just below Conowingo Dam, a lone fly fisherman was doing a good job mimicking the late-April caddisfly hatch, successfully reeling in numerous surface-feeding Hickory Shad.
You may have noticed the extraordinary number of introduced fish species listed in this account of a visit to Conowingo Dam.  Sorry to say that there are two more: the Flathead Catfish (Pylodictis olivaris) and the Blue Catfish (Ictalurus furcatus).  Like the Northern Snakehead, each has become a plentiful invasive species during recent years.  Unlike the Northern Snakehead, these catfish are “native transplants”, species introduced from populations in the Mississippi River and Gulf Slope drainages of the United States.  So if you visit the area, consider getting a fishing license and catching a few.  Like the snakeheads, they too are quite palatable.

The arrival of migrating Hickory Shad heralds the start of a movement that will soon include White Perch, anadromous American Shad, and dozens of other fish species that swim upstream during the springtime.  Do visit Fisherman’s Park at Conowingo Dam to see this spectacle before it’s gone.  The fish and birds have no time to waste, they’ll soon be moving on.

To reach Exelon’s Conowingo Fisherman’s Park from Rising Sun, Maryland, follow U.S. Route 1 south across the Conowingo Dam, then turn left onto Shuresville Road, then make a sharp left onto Shureslanding Road.  Drive down the hill to the parking area along the river.  The park’s address is 2569 Shureslanding Road, Darlington, Maryland.

A water release schedule for the Conowingo Dam can be obtained by calling Exelon Energy’s Conowingo Generation Hotline at 888-457-4076.  The recording is updated daily at 5 P.M. to provide information for the following day.

And remember, the park can get crowded during the weekends, so consider a weekday visit.

Forest vs. Woodlot

Let’s take a quiet stroll through the forest to have a look around.  The spring awakening is underway and it’s a marvelous thing to behold.  You may think it a bit odd, but during this walk we’re not going to spend all of our time gazing up into the trees.  Instead, we’re going to investigate the happenings at ground level—life on the forest floor.

Rotting logs and leaf litter create the moisture retaining detritus in which mesic forest plants grow and thrive.  Note the presence of mosses and a vernal pool in this damp section of forest.
The earliest green leaves in the forest are often those of the Skunk Cabbage (Simplocarpus foetidus).  This member of the arum family gets a head start by growing in the warm waters of a spring seep or in a stream-fed wetland.  Like many native wildflowers of the forest, Skunk Cabbage takes advantage of early-springtime sun to flower and grow prior to the time in late April when deciduous trees grow foliage and cast shade beneath their canopy.
Among the bark of dead and downed trees, the Mourning Cloak butterfly (Nymphalis antiopa) hibernates for the winter.  It emerges to alight on sun-drenched surfaces in late winter and early spring.
Another hibernating forest butterfly that emerges on sunny early-spring days is the Eastern Comma (Polygonia comma), also known as the Hop Merchant.
In a small forest brook, a water strider (Gerridae) chases its shadow using the surface tension of the water to provide buoyancy.  Forests are essential for the protection of headwaters areas where our streams get their start.
Often flooded only in the springtime, fish-free pools of water known as vernal ponds are essential breeding habitat for many forest-dwelling amphibians.  Unfortunately, these ephemeral wetland sites often fall prey to collecting, dumping, filling, and vandalism by motorized and non-motorized off-roaders, sometimes resulting in the elimination of the populations of frogs, toads, and salamanders that use them.
Wood Frogs (Lithobates sylvaticus) emerge from hiding places among downed timber and leaf litter to journey to a nearby vernal pond where they begin calling still more Wood Frogs to the breeding site.
Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the pond dries up in the summertime.  It’s a risky means of reproduction, but it effectively evades the enormous appetites of fish.
When the egg laying is complete, adult Wood Frogs return to the forest and are seldom seen during the rest of the year.
In early spring, Painted Turtles emerge from hideouts in larger forest pools, particularly those in wooded swamps, to bask in sunny locations.
Dead standing trees, often called snags, are essential habitats for many species of forest wildlife.  There is an entire biological process, a micro-ecosystem, involved in the decay of a dead tree.  It includes fungi, bacteria, and various invertebrate animals that reduce wood into the detritus that nourishes and hydrates new forest growth.
Birds like this Red-headed Woodpecker feed on insects found in large snags and nest almost exclusively in them.  Many species of wildlife rely on dead trees, both standing and fallen, during all or part of their lives.

There certainly is more to a forest than the living trees.  If you’re hiking through a grove of timber getting snared in a maze of prickly Multiflora Rose (Rosa multiflora) and seeing little else but maybe a wild ungulate or two, then you’re in a has-been forest.  Logging, firewood collection, fragmentation, and other man-made disturbances inside and near forests take a collective toll on their composition, eventually turning them to mere woodlots.  Go enjoy the forests of the lower Susquehanna valley while you still can.  And remember to do it gently; we’re losing quality as well as quantity right now—so tread softly.

The White-tailed Deity in a woodlot infested by invasive tangles of Multiflora Rose.

Spotted Lanternfly in the Lower Susquehanna River Watershed

Second Mountain Hawk Watch is located on a ridge top along the northern edge of the Fort Indiantown Gap Military Reservation and the southern edge of State Game Lands 211 in Lebanon County, Pennsylvania.  The valley on the north side of the ridge, also known as St. Anthony’s Wilderness, is drained to the Susquehanna by Stony Creek.  The valley to the south is drained toward the river by Indiantown Run, a tributary of Swatara Creek.

The hawk watch is able to operate at this prime location for observing the autumn migration of birds, butterflies, dragonflies, and bats through the courtesy of the Pennsylvania Game Commission and the Garrison Commander at Fort Indiantown Gap.  The Second Mountain Hawk Watch Association is a non-profit organization that staffs the count site daily throughout the season and reports data to the North American Hawk Watch Association (posted daily at hawkcount.org).

Today, Second Mountain Hawk Watch was populated by observers who enjoyed today’s break in the rainy weather with a visit to the lookout to see what birds might be on the move.  All were anxiously awaiting a big flight of Broad-winged Hawks, a forest-dwelling Neotropical species that often travels back to its wintering grounds in groups exceeding one hundred birds.  Each autumn, many inland hawk watches in the northeast experience at least one day in mid-September with a Broad-winged Hawk count exceeding 1,000 birds.  They are an early-season migrant and today’s southeast winds ahead of the remnants of Hurricane Florence (currently in the Carolinas) could push southwest-heading “Broad-wings” out of the Piedmont Province and into the Ridge and Valley Province for a pass by the Second Mountain lookout.

The flight turned out to be steady through the day with over three hundred Broad-winged Hawks sighted.  The largest group consisted of several dozen birds.  We would hope there are probably many more yet to come after the Florence rains pass through the northeast and out to sea by mid-week.  Also seen today were Bald Eagles, Ospreys, American Kestrels, and a migrating Red-headed Woodpecker.

Migrating Broad-winged Hawks circle on a thermal updraft above Second Mountain Hawk Watch to gain altitude before gliding away to the southwest.

Migrating insects included Monarch butterflies, and the three commonest species of migratory dragonflies: Wandering Glider, Black Saddlebags, and Common Green Darner.  The Common Green Darners swarmed the lookout by the dozens late in the afternoon and attracted a couple of American Kestrels, which had apparently set down from a day of migration.  American Kestrels and Broad-winged Hawks feed upon dragonflies and often migrate in tandem with them for at least a portion of their journey.

Still later, as the last of the Broad-winged Hawks descended from great heights and began passing by just above the trees looking for a place to settle down, a most unwelcome visitor arrived at the lookout.  It glided in from the St. Anthony’s Wilderness side of the ridge on showy crimson-red wings, then became nearly indiscernible from gray tree bark when it landed on a limb.  It was the dreaded and potentially invasive Spotted Lanternfly (Lycorma delicatula).  This large leafhopper is native to Asia and was first discovered in North America in the Oley Valley of eastern Berks County, Pennsylvania in 2014.  The larval stage is exceptionally damaging to cultivated grape and orchard crops.  It poses a threat to forest trees as well.  Despite efforts to contain the species through quarantine and other methods, it’s obviously spreading quickly.  Here on the Second Mountain lookout, we know that wind has a huge influence on the movement of birds and insects.  The east and southeast winds we’ve experienced for nearly a week may be carrying Spotted Lanternflies well out of their most recent range and into the forests of the Ridge and Valley Province.  We do know for certain that the Spotted Lanternfly has found its way into the Lower Susquehanna River Watershed.

This adult Spotted Lanternfly landed in a birch tree behind the observers at the Second Mountain Hawk Watch late this afternoon.  It was first recognized by its bright red wings as it glided from treetops on the north side of the lookout.

Noxious Benefactor

It’s sprayed with herbicides.  It’s mowed and mangled.  It’s ground to shreds with noisy weed-trimmers.  It’s scorned and maligned.  It’s been targeted for elimination by some governments because it’s undesirable and “noxious”.  And it has that four letter word in its name which dooms the fate of any plant that possesses it.   It’s the Common Milkweed, and it’s the center of activity in our garden at this time of year.  Yep, we said milk-WEED.

Now, you need to understand that our garden is small—less than 2,500 square feet.  There is no lawn, and there will be no lawn.  We’ll have nothing to do with the lawn nonsense.  Those of you who know us, know that the lawn, or anything that looks like lawn, are through.

Anyway, most of the plants in the garden are native species.  There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed.  The unusually wet growing season in 2018 has been very kind to these plants.  They are still very green and lush.  And the animals that rely on them are having a banner year.  Have a look…

The flowers of the Common Milkweed were exceptionally fragrant this year.  At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into our building and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from our walls (100 feet from his).
Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species).  The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases.  Are you following this?  Remember as we proceed, milkweed is “noxious”.
Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.
A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.
Following the pollination of the flowers, seed pods will begin to grow.  We trim these off the plants.  The removal of the extra weight allows most of the stems to remain erect through stormy weather.  You’ll still get new plants from underground runners.  As you may have guessed, we’re trying to keep these plants upright and strong to host Monarch butterfly larvae.

We’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects.  This year, these plants are exceptionally colorful for late-August due to the abundance of rain.  The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.

Big Bluestem, a native warm-season grass in flower.
Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower.  This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the  herd animals and fires of the prairie to prevent succession and allow it to thrive.
Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.
Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.
Indiangrass (Sorghastrum nutans) in flower.  This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA).  They have an unbelievably large selection of indigenous species.  You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.
A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea).  Yes, it is that Echinacea, the same one used as a supplement and home remedy.

There was Monarch activity in the garden today like we’ve never seen before—and it revolved around milkweed and the companion plants.

A female Monarch laying eggs on a Common Milkweed leaf.
A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf.  Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.
Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf.  There were over thirty of these caterpillars in just a ten by ten feet area this morning.  We hope that if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!
A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.
Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant.  Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle.  Need more milkweed!
After benefiting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.
Two hours later, the chrysalis is complete.
Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one.  An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.
There it is, soon ready to fly away.  And all courtesy of the noxious milkweed.
A chrysalis can often be found on man-made objects too.  This one is on the rim of a flower pot.
Ornamental flowers can attract adult Monarch butterflies seeking nectar.  We’re now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides.  There’s growing concern over the impact these compounds may be having on pollinating species of animals.  Oh…and we don’t mow, whack, cut, mutilate, or spray herbicides on our milkweed, but you probably figured that out already.

 SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York.

Anthropoavians

Temperatures plummeted to well below freezing during the past two nights, but there was little sign of it in Conewago Falls this morning.  The fast current in the rapids and swirling waters in flooded Pothole Rocks did not freeze.  Ice coated the standing water in potholes only in those rocks lacking a favorable orientation to the sun for collecting solar heat during the day to conduct into the water during the cold nights.

On the shoreline, the cold snap has left its mark.  Ice covers the still waters of the wetlands.  Frost on exposed vegetation lasted until nearly noontime in shady areas.  Insect activity is now grounded and out of sight.  The leaves of the trees tumble and fall to cover the evidence of a lively summer.

The nocturnal bird flight is narrowing down to just a few species.  White-throated Sparrows, a Swamp Sparrow (Melospiza georgiana), and Song Sparrows are still on the move.  Though their numbers are not included in the migration count, hundreds of the latter are along the shoreline and in edge habitat around the falls right now.  Song Sparrows are present year-round, migrate at night, and are not seen far from cover in daylight, so migratory movements are difficult to detect.  It is certain that many, if not all of the Song Sparrows here today have migrated and arrived here recently.  The breeding population from spring and summer has probably moved further south.  And many of the birds here now may remain for the winter.  Defining the moment of this dynamic, yet discrete, population change and logging it in a count would certainly require different methods.

Song Sparrows are now abundant in the brushy edges of fields and woodlands.  They may even break into song on sunny days.

Diurnal migration was foiled today by winds from southerly directions and moderating temperatures.  The only highlight was an American Robin flight that extended into the morning for a couple of hours after daybreak and totaled over 800 birds.  This flight was peppered with an occasional flock of blackbirds.  Then too, there were the villains.

CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS

They’re dastardly, devious, selfish, opportunistic, and abundant.  Today, they were the most numerous diurnal migrant.  Their numbers made this one of the biggest migration days of the season, but they are not recorded on the count sheet.  It’s no landmark day.  They excite no one.  For the most part, they are not recognized as migrants because of their nearly complete occupation of North America south of the taiga.  If people build on it or alter it, these birds will be there.  They’re everywhere people are.  If the rotten attributes of man were wrapped up into one bird, an “anthropoavian”, this would be it.

Meet the European Starling (Sturnus vulgaris).  Introduced into North America in 1890, the species has spread across the entire continent.  It nests in cavities in buildings and in trees.  Starlings are aggressive, particularly when nesting, and have had detrimental impacts on the populations of native cavity nesting birds, particularly Red-headed Woodpeckers, Purple Martins (Progne subis), and Eastern Bluebirds.  They commonly terrorize these and other native species to evict them from their nest sites.  European Starlings are one of the earlier of the scores of introduced plants and animals we have come to call invasive species.

Noisy flocks of European Starlings are right at home on man-made structures in city and country.

Today, thousands of European Starlings were on the move, working their way down the river shoreline and raiding berries from the vines and trees of the Riparian Woodlands.  My estimate is between three and five thousand migrated through during the morning.  But don’t worry, thousands more will be around for the winter.

European Starlings mob a Sharp-shinned Hawk from above, a common behavior.
An Eastern Bluebird feeds on the few berries left untouched by passing European Starlings.

Living in the Shadows

They get a touch of it here, and a sparkle or two there.  Maybe, for a couple of hours each day, the glorious life-giving glow of the sun finds an opening in the canopy to warm and nourish their leaves, then the rays of light creep away across the forest floor, and it’s shade for the remainder of the day.

The flowering plants which thrive in the understory of the Riparian Woodlands often escape much notice.  They gather only a fraction of the daylight collected by species growing in full exposure to the sun.  Yet, by season’s end, many produce showy flowers or nourishing fruits of great import to wildlife.  While light may be sparingly rationed through the leaves of the tall trees overhead, moisture is nearly always assured in the damp soils of the riverside forest.  For these plants, growth is slow, but continuous.  And now, it’s show time.

So let’s take a late-summer stroll through the Riparian Woodlands of Conewago Falls, minus the face full of cobwebs, and have a look at some of the strikingly beautiful plants found living in the shadows.

Oxeye (Heliopsis helianthoides) is common on the interior and along the edges of Riparian Woodland.  Specimens in deep shade flower less profusely and average less than half the height of the five feet tall inhabitants of edge environs.
Pale Touch-Me-Not (Impatiens pallida) is one of two species of native Impatiens found in the river floodplain.  Both are known as Jewelweed.  The stems and leaves of the indigenous Impatiens retain a great quantity of water, so life in filtered sunlight is essential to prevent desiccation.  Contrary to popular folklore, extracts of Jewelweed plants are not effective treatments of Poison Ivy (Toxicodendron radicans) contact dermatitis.
Spotted Touch-Me-Not (Impatiens capensis) is typically found in wetter soil than I. pallida.  Both Jewelweeds develop popping capsules which help to distribute the seeds of these annual wildflowers.  “Touch Me Not”, or you’ll be wearing tiny seeds.
Green-headed Coneflower (Rudbeckia laciniata) grows to heights of eight feet in full sun, hence its alternate common name, Tall Coneflower.  In deep shade, it may not exceed two feet in height.  Floodplains are the prime domain of this perennial.
Wingstem (Verbesina alternifolia) normally flowers no earlier than late August.  The bases of the leaves are continued onto the stem of the plant to form wings which extend downward along its length.  This wildflower tolerates shade, but flowers more profusely along the woodland edge.
Great Lobelia (Lobelia siphilitica), or Great Blue Lobelia, is a magnificent wetland and moist woodland wildflower, usually attaining three feet in height and adorned with a plant-topping spike of blossoms.  Invasive Japanese Stiltgrass (Microstegium vimineum) can be seen here competing with this plant, resulting in a shorter, less productive Lobelia.  Stiltgrass was not found in the Susquehanna River floodplain at Conewago Falls until sometime after 1997.  It has spread to all areas of woodland shade, its tiny seeds being blown and translocated along roads, mowed lots, trails, and streams to quickly colonize and overtake new ground.
American Bladdernut (Staphylea trifolia), a shrub of shaded woods, develops inflated capsules which easily float away during high water to distribute the seeds contained inside.
Buttonbush (Cephalanthus occidentalis) is a shrub of wet soils which produces a strange spherical flower, followed by this globular seed cluster.
Common Pawpaw (Asimina triloba) is a colony-forming small tree which produces a fleshy fruit.  It is the host plant for the caterpillars of the Zebra Swallowtail.  The plant and the butterfly approach the northern limit of their geographic range at Conewago Falls.
Common Spicebush (Lindera benzoin) is a widespread understory shrub in wet floodplain soils.  It is the host plant for the caterpillars of the Spicebush Swallowtail (Papilio troilus).
Sweet Autumn Virgin’s Bower (Clematis terniflora) is an escape from cultivation which has recently naturalized in the edge areas of the Conewago Falls Riparian Woodlands.  This vine is very showy when flowering and producing seed, but can be detrimental to some of the understory shrubs upon which it tends to climb.

SOURCES

Long, David; Ballentine, Noel H.; and Marks, James G., Jr.  1997.  Treatment of Poison Ivy/Oak Allergic Contact Dermatitis With an Extract of Jewelweed.  American Journal of Contact Dermatitis.  8(3): pp. 150-153.

Newcomb, Lawrence.  1977.  Newcomb’s Wildflower Guide.  Little, Brown and Company.  Boston, Massachusetts.

The Dungeon

There’s something frightening going on down there.  In the sand, beneath the plants on the shoreline, there’s a pile of soil next to a hole it’s been digging.  Now, it’s dragging something toward the tunnel it made.  What does it have?  Is that alive?

We know how the system works, the food chain that is.  The small stuff is eaten by the progressively bigger things, and there are fewer of the latter than there are of the former, thus the whole network keeps operating long-term.  Some things chew plants, others devour animals whole or in part, and then there are those, like us, that do both.  In the natural ecosystem, predators keep the numerous little critters from getting out of control and decimating certain other plant or animal populations and wrecking the whole business.  When man brings an invasive and potentially destructive species to a new area, occasionally we’re fortunate enough to have a native species adapt and begin to keep the invader under control by eating it.  It maintains the balance.  It’s easy enough to understand.

Japanese Beetles (Popillia japonica) seen here on Halberd-leaved Rose Mallow.  Without predation, exploding numbers of this invasive non-indigenous insect can defoliate and kill numerous species of plants in a given area.
The Song Sparrow (Melospiza melodia) is a generalist feeder, eating seeds and invertebrates including Japanese Beetles.  This species is the omnipresent year-round occupant of shoreline vegetation along the lower Susquehanna River.

Late summer days are marked by a change in the sounds coming from the forests surrounding the falls.  For birds, breeding season is ending, so the males cease their chorus of songs and insects take over the musical duties.  The buzzing calls of male “annual cicadas” (Neotibicen species) are the most familiar.  The female “annual cicada” lays her eggs in the twigs of trees.  After hatching, the nymphs drop to the ground and burrow into the soil to live and feed along tree roots for the next two to five years.  A dry exoskeleton clinging to a tree trunk is evidence that a nymph has emerged from its subterranean haunts and flown away as an adult to breed and soon thereafter die.  Flights of adult “annual cicadas” occur every year, but never come anywhere close to reaching the enormous numbers of “periodical cicadas” (Magicicada species).  The three species of “periodical cicadas” synchronize their life cycles throughout their combined regional populations to create broods that emerge as spectacular flights once every 13 or 17 years.

An “annual cicada” also known as a “dog-day cicada”, clings to the stem of a Halberd-leaved Rose Mallow at Conewago Falls.

For the adult cicada, there is danger, and that danger resembles an enormous bee.  It’s an Eastern Cicada Killer (Specius speciosus) wasp, and it will latch onto a cicada and begin stinging while both are in flight.  The stings soon paralyze the screeching, panicked cicada.  The Cicada Killer then begins the task of airlifting and/or dragging its victim to the lair it has prepared.  The cicada is placed in one of more than a dozen cells in the tunnel complex where it will serve as food for the wasp’s larvae.  The wasp lays an egg on the cicada, then leaves and pushes the hole closed.  The egg hatches in a several days and the larval grub is on its own to feast upon the hapless cicada.

An Eastern Cicada Killer (Sphecius speciosus) along the river shoreline. Despite their intimidating appearance, they do not sting humans and can be quite docile when approached.

Other species in the Solitary Wasp family (Sphecidae) have similar life cycles using specific prey which they incapacitate to serve as sustenance for their larvae.

A Solitary Wasp, one of the Thread-waisted Wasps (Ammophila species), drags a paralyzed moth caterpillar to its breeding dungeon in the sandy soil at Conewago Falls.  For the victim, there is no escape from the crypt.

The Solitary Wasps are an important control on the populations of their respective prey.  Additionally, the wasp’s bizarre life cycle ensures a greater survival rate for its own offspring by providing sufficient food for each of its progeny before the egg beginning its life is ever put in place.  It’s complete family planning.

The cicadas reproduce quickly and, as a species, seem to endure the assault by Cicada Killers, birds, and other predators.  The periodical cicadas (Magicicada), with adult flights occurring as a massive swarm of an entire population every thirteen or seventeen years, survive as species by providing predators with so ample a supply of food that most of the adults go unmolested to complete reproduction.  Stay tuned, 2021 is due to be the next periodical cicada year in the vicinity of Conewago Falls.

SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York.

Fussy Eaters

She ate only toaster pastries…that’s it…nothing else.  Every now and then, on special occasions, when a big dinner was served, she’d have a small helping of mashed potatoes, no gravy, just plain, thank you.  She received all her nutrition from several meals a week of macaroni and cheese assembled from processed ingredients found in a cardboard box.  It contains eight essential vitamins and minerals, don’t you know?  You remember her, don’t you?

Adult female butterflies must lay their eggs where the hatched larvae will promptly find the precise food needed to fuel their growth.  These caterpillars are fussy eaters, with some able to feed upon only one particular species or genus of plant to grow through the five stages, the instars, of larval life.  The energy for their fifth molt into a pupa, known as a chrysalis, and metamorphosis into an adult butterfly requires mass consumption of the required plant matter.  Their life cycle causes most butterflies to be very habitat specific.  These splendid insects may visit the urban or suburban garden as adults to feed on nectar plants, however, successful reproduction relies upon environs which include suitable, thriving, pesticide-free host plants for the caterpillars.  Their survival depends upon more than the vegetation surrounding the typical lawn will provide.

The Monarch (Danaus plexippus), a butterfly familiar in North America for its conspicuous autumn migrations to forests in Mexico, uses the milkweeds (Asclepias) almost exclusively as a host plant.  Here at  Conewago Falls, wetlands with Swamp Milkweed (Asclepias incarnata) and unsprayed clearings with Common Milkweed (A. syriaca) are essential to the successful reproduction of the species.  Human disturbance, including liberal use of herbicides, and invasive plant species can diminish the biomass of the Monarch’s favored nourishment, thus reducing significantly the abundance of the migratory late-season generation.

Monarch caterpillar after a fourth molt.  The fifth instar feeding on Swamp Milkweed.
A fifth molt begets the Monarch pupa, the chrysalis, from which the showy adult butterfly will emerge.
Adult Monarch feeding on Goldenrod (Solidago) nectar.

Butterflies are good indicators of the ecological health of a given environment.  A diversity of butterfly species in a given area requires a wide array of mostly indigenous plants to provide food for reproduction.  Let’s have a look at some of the species seen around Conewago Falls this week…

An adult Silvery Checkerspot (Chlosyne nycteis) visiting a nectar plant, Partridge Pea (Chamaecrista fasciculata).  Wingstem (Verbesina alternifolia), a plant of the Riparian Woodlands, is among the probable hosts for the caterpillars.
A Gray Hairstreak (Strymon melinus) visits Crown Vetch, a possible host plant.  Other potential larval food in the area includes Partridge Pea, Halberd-leaved Rose Mallow (Hibiscus laevis) of the river shoreline, and Swamp Rose Mallow (Hibiscus moscheutos), a plant of wetlands.
The Eastern Tailed Blue (Cupido comyntas) may use Partridge Pea , a native wildflower species, and the introduced Crown Vetch (Securigera/Coronilla varia) as host and nectar plants at Conewago Falls.
The Least Skipper (Ancyloxypha numitor) is at home among tall grasses in woodland openings, at riverside, and in the scoured grassland habitat of the Pothole Rocks in the falls.  Host plants available include Switchgrass (Panicum vigatum), Freshwater Cordgrass (Spartina pectinata), and Foxtails (Setaria).
The Zabulon Skipper (Poanes zabulon) is an inhabitant of moist clearings where the caterpillars may feed upon Lovegrasses (Eragrostis) and Purpletop (Tridens flavus).
The Eastern Tiger Swallowtail (Papilio glaucus), a female seen here gathering nectar from Joe-Pye Weed (Eutrochium), relies upon several forest trees as hosts. Black Cherry (Prunus serotina), Willow (Salix), Yellow Poplar (Liriodendron tulipifera), also known as Tuliptree, and Green Ash (Fraxinus pennsylvanica) are among the local species known to be used.  The future of the latter food species at Conewago Falls is doubtful.  Fortunately for the Eastern Tiger Swallowtail, the “generalist” feeding requirements of this butterfly’s larvae enable the species to survive the loss of a host plant.
A female Eastern Tiger Swallowtail, black morph, gathering nectar from Joe-Pye Weed.
The Zebra Swallowtail (Protographium marcellus), an adult seen here on Joe-Pye Weed, feeds exclusively upon Pawpaw (Asimina) trees as a caterpillar.  This butterfly species may wander, but its breeding range is limited to the moist Riparian Woodlands where colonial groves of Pawpaw may be found.  The Common Pawpaw (Asimina triloba), our native species in Pennsylvania, and the Zebra Swallowtail occur at the northern edge of their geographic ranges in the Lower Susquehanna River Watershed.  Planting Pawpaw trees as an element of streamside reforestation projects certainly benefits this marvelous butterfly.

The spectacularly colorful butterflies are a real treat on a hot summer day.  Their affinity for showy plants doubles the pleasure.

By the way, I’m certain by now you’ve recalled that fussy eater…and how beautiful she grew up to be.

SOURCES

Brock, Jim P., and Kaufman, Kenn.  2003.  Butterflies of North America.  Houghton Mifflin Company.  New York, NY.