Photo of the Day

Mammals of the Lower Susquehanna River Watershed: A White-footed Mouse Peers from its Nest
Uncle Tyler Dyer reminds all his vegetarian friends to speak clearly when ordering the “House Salad” in a noisy restaurant, otherwise you may go hungry.  Unlike Uncle Ty, the White-footed Mouse (Peromyscus leucopus), seen here in its nest, is omnivorous, so it seldom goes hungry.

Photo of the Day

Common Raven
Resembling an overgrown crow with a wedge-shaped tail, the Common Raven is an oft times comical corvid; this one twisting its head to have a gander at observers on a ridgetop hawk-counting lookout.

Photo of the Day

Purple Finch feeding on Green Ash seeds.
It seems a bit early, but Purple Finches are indeed beginning to transit the Lower Susquehanna River Watershed on their way south. This one is feeding on the abundance of seeds produced by a Green Ash that has, at least thus far, survived the Emerald Ash Borer invasion.

Photo of the Day

Vallisneria "Pearling" as it Produces Oxygen
Submersed aquatic plants in streams, lakes, ponds, bays, and estuaries do more than take up nutrients and provide habitat for fish and other organisms, they produce oxygen during photosynthesis.  Here we see tapegrass (Vallisneria) in bright sunlight releasing a visible string of oxygen bubbles, an emission known as “pearling”.  British chemist, theologian, and philosopher Joseph Priestly (1733-1804), who spent his final decade residing along the Susquehanna in Northumberland, Pennsylvania, isolated oxygen during experiments in 1774 by exposing mercuric oxide to direct sunlight.  During the following year, Priestly published his findings in “An Account of Further Discoveries in Air”, describing what he called “dephlogisticated air”, the gas later named oxygen.  To observe and record the effects of pure oxygen in the absence of atmospheric air, Priestly first tested it on a mouse, then breathed it himself.

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Freshwater Bryozoan Colony (Pectinatella magnifica) and an Eastern Amberwing
Those who happen to come upon it might think this football-sized gelatinous blob is a sure sign of pollution.  A freshwater bryozoan (Pectinatella magnifica) colony is composed of a single microscopic founder and its many clones.  Despite its bizarre appearance, the “moss animal” is an indicator of good water quality.  Pectinatella magnifica is found in clear lentic (still) waters of streams, lakes, and ponds where each individual in the colony feeds by extending a disk of sticky tentacles, called a lophophore, from within its protective sheath to capture single-celled algae (e.g., diatoms) and other plankton.  From now through autumn, these bryozoans are reproducing by means of cell-filled statoblasts, durable little seedlike pods which can survive the harsh conditions of both winter and drought and sometimes be transported by animals, wind, or water currents to new areas.  Spring weather and/or rehydration of a dried-up lentic pool stimulates a statoblast to open, the cells contained therein then develop into a zooid that attempts to start a new colony by cloning itself.

Photo of the Day

Zabulon Skipper on Pickerelweed
A female Zabulon Skipper visits a cluster of Pickerelweed blossoms.  The Zabulon Skipper is a small butterfly of our streamsides, riversides, damp meadows, and other moist grassy spaces.  The Pickerelweed is an emergent plant of lakes, ponds, and wetlands.  Add it to your next project to improve water quality and help pollinators like the Zabulon Skipper.  You may even attract a hummingbird or two!   

Photo of the Day

Gray Catbird and Black Chokeberry
The fruits of a Black Chokeberry (Aronia melanocarpa) prove irresistible to this Gray Catbird.  Chokeberry is a native clump-forming shrub that reaches a height of less than ten feet.  It is tolerant of wet soils and makes a good choice for inclusion in plantings alongside streams and ponds, as well as in rain gardens.  Springtime clusters of white flowers yield berries by this time each summer.  By turning red as the fruits ripen, the foliage helps attract not only catbirds, but robins, waxwings, and other species that, in exchange for a meal, will assure dispersal of the plant’s seeds in their droppings.  With considerable sweetening, tart chokeberries can be used for juicing and the creation of jams, jellies, and preserves.

Photo(s) of the Day

A tallgrass prairie wildflower and warm-season grass planting: Big Bluestem
This tallgrass prairie wildflower planting on a health campus in Hershey, Pennsylvania, enhances stormwater management and benefits butterflies and other wildlife.  Reducing the acreage maintained as manicured lawn has helped disperse the large flocks of resident Canada Geese (a population of invasive native transplants) that frequented the property and posed a serious hazard to medevac helicopters flying in and out of the facility.
A tallgrass prairie wildflower and warm-season grass planting
Big Bluestem, a warm-season grass, dominates the site and is complemented by Indiangrass and tall wildflowers including Common Milkweed, Wild Bergamot, Oxeye, Black-eyed Susan, Prairie Coneflower, and Purple Coneflower.

Photo of the Day

Annual Wildflowers Along Corn Field.
Spectacular annual wildflowers in bloom along a border separating a fitness trail from a field of maize in Hershey, Pennsylvania.  Such plantings can provide vital habitat for pollinators that otherwise find no sustenance among monocultures of neonicotinoid-treated crops like corn and soybeans.

Photo of the Day

Eastern Bluebird Family at Mealworm Feeding Station
This morning, our pair of Eastern Bluebirds (female lower right, male’s feet just barely visible atop the petri dish inside the feeder enclosure) led their offspring back to the susquehannawildlife.net headquarters for a visit to the mealworm feeding station, which they promptly emptied.  Exactly fourteen days ago, these four young, plus one not visible in this image, fledged from the nest box located less than twenty feet away.  They’ve been under the constant care of their parents ever since.

Photo of the Day

Buttonbush flower cluster
Is it the latest image from NASA’s new Webb Space Telescope?  Nope, it’s the globular flower cluster of the Buttonbush, a native shrub species found throughout the Lower Susquehanna River Watershed.  Buttonbush thrives in wet soil and seldom grows taller than 10 feet in height.  Try it along stream banks, in stormwater retention basins, and in rain gardens fed by surface runoff or the outflow from your downspouts.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Yellow-crowned Night Herons
You remember the Photo of the Day from back on April 7th, don’t you?  You know, the one with the pair of endangered Yellow-crowned Night Herons at their nest.  Well, meet their kids.

Photo of the Day

Jurassic Diabase: Dinosaur Rock
If you’re looking for evidence of Jurassic dinosaurs in the Lower Susquehanna valley, well, you’re out of luck.  If you want to understand why, just visit Dinosaur Rock on Pennsylvania State Game Lands #145 along Colebrook/Mount Wilson Road northwest of its Pennsylvania Turnpike overpass in Lebanon County.  Dinosaur Rock is the unique remnant of a subterranean Early Jurassic diabase intrusion, a sill, around which softer Triassic Hammer Creek sediments (sandstone and conglomerate) have eroded away.  Spheroidal weathering has left the exposed diabase boulders with rounded edges.  In the lower Susquehanna region, igneous diabase is the only remaining rock from the Jurassic Period.  Any sediments that may have contained dinosaur fossils have been eroded away during the millions of years since.  Be certain to click on the “Geology, Fossils, and More” tab at the top of this page to check out Jurassic Diabase and the earlier dinosaurs of the region, those of the Triassic Period.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Eastern Bluebird
First thing this morning, this juvenile Eastern Bluebird left the safety of a nest box at the susquehannawildlife.net headquarters.  Its parents remain nearby and will continue watching over and feeding it for a couple of weeks.  Remember to give young birds and animals plenty of space.  Keep your covert cats in the house and your overt dogs on a leash.  And don’t assume that the cute little animals you find need your help, it’s almost always best to just leave them alone.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Great Horned Owl
This juvenile Great Horned Owl and its sibling have attained their first set of flight feathers and left the nest.  The duo is still being watched and fed by their parents, which remain hidden in a nearby woodlot.

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Birds of Conewago Falls in the Lower Susquehanna River Watershed: "Taiga Merlin"
A “Taiga Merlin” (Falco columbarius columbarius) with an Eastern Kingbird snatched from midair.  Both these species are accomplished fliers that rely upon aerial pursuit to catch their prey, the former preferring small birds and the latter flying insects.

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Birds of Conewago Falls in the Lower Susquehanna River Watershed: Yellow-throated Vireo
A Yellow-throated Vireo (Vireo flavifrons) in a Shagbark Hickory (Carya ovata) along the Conewago Creek east of Conewago Falls.  This Neotropical migrant nests sparingly along stream courses throughout the Lower Susquehanna River Watershed.

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Birds of Conewago Falls in the Lower Susquehanna River Watershed: Common Yellowthroat
The Common Yellowthroat is one of our most frequently encountered warblers.  It can be found in almost any shrubby habitat, but is particularly numerous in streamside and wetland thickets.  Many remain through the summer to nest and raise young.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Great Crested Flycatcher
Great Crested Flycatchers (Myiarchus crinitus) are arriving now in forests throughout the lower Susquehanna valley.  Those that don’t pass through will stay to nest in tree cavities including old woodpecker excavations, so let those snags standing!

Photo of the Day

The Blue-winged Warbler is a Neotropical migrant that nests among successional growth near taller timber in scattered locations throughout the Lower Susquehanna River Watershed.  Its song, a ringing “beee-bzzz”, is one of the easiest in the warbler family repertoire to recognize and remember.  The Blue-winged Warbler has become less widespread as a breeding species as forests and woodlots have matured and utility right-of-ways are sprayed or cleared of shrubs and small trees with greater frequency.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Northern Parula
The Northern Parula is a Neotropical migrant that nests in mature forest trees along the lower Susquehanna.  It is a warbler most often located by listening for its buzzy song, “zzzzzzzup”, then searching the treetops in the area with hope of detecting its movements there.

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Birds of Conewago Falls in the Lower Susquehanna River Watershed: Blackburnian Warbler
The Blackburnian Warbler, a Neotropical migrant, feeds high in the canopy of mature forests during stopovers in the Lower Susquehanna River Watershed, so you need to look up to find one.  This male was seen searching for insects along the branches of an American Beech (Fagus grandifolia).

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.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Rusty Blackbird
In spring, the majority of migrating Rusty Blackbirds move north through the lower Susquehanna basin in late March and April.  Some, like this female seen yesterday along a forested tributary of Conewago Creek east of Conewago Falls, linger into May.  Because it is almost exclusively a denizen of wet bottomlands, the Rusty Blackbird is the least numerous of the regularly occurring blackbirds in our region.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Yellow-rumped Warbler
The handsome Yellow-rumped Warbler is one of the earliest and most numerous of the warblers to migrate through the Lower Susquehanna River Watershed each spring.  Look for them now in woodlots and forests throughout the area.

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If you’ve ever worked in a plant nursery at this time of year, you’ve certainly heard this inquiry from customers looking for something unique, “What is that little tree with the pink-purple blooms that’s flowering right now along the edge of the woods?”  It’s the Eastern Redbud (Cercis canadensis), also known as the Judas Tree, a spectacular species for inclusion in garden landscapes, along forest edges, or as part of a vegetated riparian buffer.  In coming weeks, the showy blossoms, which pollinators adore, will give way to an abundance of handsome heart-shaped leaves.  The northern edge of the native range for this member of the legume (pea) family happens to include the Lower Susquehanna River Watershed, so it does quite well here.  Because the Eastern Redbud only grows to a height of twenty to thirty feet, it can be planted near homes and other buildings.  It would make a great choice for your Arbor Day project this Friday, April 29.

Photo of the Day

Dragonflies and Damselflies of the Lower Susquehanna River Watershed: Fragile Forktail nymph
The aquatic larval stage of a damselfly is commonly known as a nymph.  It feeds on small underwater invertebrates, then, as an adult, transitions to grabbing flying insects in midair.  While many species inhabit streams, Fragile Forktail (Ischnura posita) nymphs are found primarily in wetlands and small pools of water. This one was produced from eggs laid last summer among submerged vegetation in the susquehannawildlife.net headquarters pond.  In just a few weeks, it will climb a stem or cluster of leaves and transform into a colorful adult-stage damselfly known as an imago.  To see a photo gallery featuring this and other species of odonates found in the Lower Susquehanna River Watershed, click on the “Damselflies and Dragonflies” tab at the top of this page.

Photo of the Day

Spiders of the Lower Susquehanna River Watershed: "Tiger" Wolf Spider
A “Tiger” Wolf Spider (Tigrosa species) lurks beneath the doorstep at the susquehannawildlife.net headquarters.  These arachnids reach only about one inch in length but appear startlingly larger due to their husky build.  To feed, Wolf Spiders spin no web for snagging flying insects.  Instead, they keep watch with their eight eyes, then ambush or chase down suitable prey.  If handled roughly or pinched between an object such as a shoe and your skin, Wolf Spiders can inject a sore-producing venom.  We like having them around our entranceway, just to keep a few eyes on things.

Photo of the Day

Invasive Trees and Plants of the Lower Susquehanna River Watershed: Callery Pear including Bradford Pear
Presently in the valleys of the Lower Susquehanna River Watershed, you’re sure to see a gorgeous nightmare, showy stands of flowering Callery Pear (Pyrus calleryana).  Invasive groves like this one quickly dominate successional habitat and often create monocultures, often excluding native pioneer trees like Eastern Red Cedar and several species of deciduous hardwood.  The void beneath the pear trees in this photograph shows how deer browsing can intensify the damage, preventing other plant species from becoming established in the understory.  In autumn, crimson foliage again makes these non-native trees a standout in the landscape.  The red leaves attract birds including American Robins and Cedar Waxwings to the abundant berries, but European Starlings usually get to them first.  Planted specimens of ornamental Callery Pears began producing fertile seeds when multiple varieties became available in addition to the self-sterile “Bradford Pears” that were planted widely during the last decades of the twentieth century.  Cross-pollination between varieties produces the fertile seeds that are distributed by starlings and other birds as they digest the fruit.