Let us travel through time for just a little while to recall those sunny, late-spring days down on the farm—back when the rural landscape was a quiet, semi-secluded realm with little in the way of traffic, housing projects, or industrialized agriculture. Those among us who grew up on one of these family homesteads, or had friends who did, remember the joy of exploring the meadows, thickets, soggy springs, and woodlots they protected.
During much of the twentieth century, low-intensity agriculture provided a haven for wildlife. Periodic disturbances helped maintain cool-season grassland and early successional habitat for a number of species we currently find in decline.
For many of us, farmland was the first place we encountered and began to understand wildlife. Vast acreage provided an abundance of space to explore. And the discovery of each new creature provided an exciting experience.
Distributed by the Pennsylvania Game Commission, artist Ned Smith’s wildlife posters introduced many residents of the lower Susquehanna region to its birds and mammals. This poster of “Birds of Field and Garden” helped us learn what to expect and search for during our forays to the farm.
Today, high-intensity agriculture, relentless mowing, urban sprawl, and the increasing costs and demand for land have all conspired to seriously deplete habitat quality and quantity for many of the species we used to see on the local farm. Unfortunately for them, farm wildlife has largely been the victim of modern economics.
For old time’s sake, we recently passed a nostalgic afternoon at Middle Creek Wildlife Management Area examining what maintenance of traditional farm habitat has done and can do for breeding birds. Join us for a quick tour to remember how it used to be at the farm next door…
Always found nesting under the forebay of the barn, the Barn Swallow relentlessly pursued flying insects over the pond and meadow.Eastern Meadowlarks arrived during March and April to begin nesting in their namesake. Their song, “spring-of-the-yearrrrr”, heralded the new season.Arriving in the meadows in early May, the Eastern Kingbird provided for its nestlings by ambushing a variety of flying insects. By August, congregations of these birds could be found gathering along ponds and streams ahead of their fall migration.In the cherry grove down by the creek, the Orchard Oriole would be singing incessantly to defend its territory.Normally seed eaters through the colder months, American Goldfinches would regularly find a source of protein in the occupants of Eastern Tent Caterpillar nests. Along the wet margins of the creek, Yellow Warblers would nest in the shrubs and small trees.The “Traill’s Flycatcher” was a familiar find in low-lying areas of successional shrubs and small trees. Today, “Traill’s Flycatcher” is recognized as two distinct species, the Alder Flycatcher (Empidonax alnorum) and the Willow Flycatcher. In the lower Susquehanna valley, the latter (seen here) is by far the most common of the two.During the nineteenth century, Eastern Bluebirds became a rarity on lower Susquehanna farms due to a combination of factors: pesticide (DDT) use, habitat loss, and competition with other birds for nest sites. The species saw a resurgence beginning in the 1970s with discontinuation of DDT applications and widespread provision of nesting boxes. Around human habitations, competition with invasive House Sparrows continues to be detrimental to their success.Purple Martins suffered a similar fate to the bluebirds. The potential for their recovery remains dubious and they continue to be very local breeders, fussy about selection of suitable man-made provisions for nesting. After considerable effort, Purple Martins have at last been attracted to nest in the condos placed for their use at Middle Creek Wildlife Management Area. In the artificial gourds, there are nesting Tree Swallows, a species which also benefits from the placement of boxes intended for bluebirds.Abandoned fields and other successional habitats were and continue to be favored homes for Field Sparrows. At almost any time of year, roving bands of Cedar Waxwings would suddenly visit old field habitat looking for berries among the shrubs and other pioneering woody growth. In early summer, after most species have already hatched their young, nesting would commence and these fruit eaters would transform into accomplished fly catchers. During the twentieth century prior to the 1980s, Ring-necked Pheasant populations in the Lower Susquehanna River Watershed were comprised of breeding descendants of introduced birds supplemented by additional releases to maintain numbers sufficient for hunting. Year-round populations did and can reside in mosaic landscapes of early successional and grassland habitats, the latter including hay fields left unmowed through the nesting season. Red-winged Blackbirds have always been a fixture of hay fields and meadows on farms. While the increase in mowing frequency has reduced their nesting success, they have persevered as a species by nesting earlier than other birds and by utilizing other landscape features such as densely vegetated stormwater basins for breeding sites. Do you recall the last time you saw a Bobolink nesting in a hay field near you? Arriving in early May as a Neotropical migrant, the Bobolink requires a cool-season grassland such as hay field through at least July to complete its nesting cycle. Even earlier this century, we remember nesting Bobolinks being more widespread on farms throughout the region. Now, you almost have to go to Middle Creek if you want to see them.Formerly more widespread in hay fields throughout the lower Susquehanna valley, the native Grasshopper Sparrow is yet another species falling victim to early mowing and intensive farming.The solution to their dilemma is as advertised. Instead of cutting the grass, why not take heed of the example set here and cut back on the tens of thousands of acres that are excessively or needlessly mowed in the Lower Susquehanna River Watershed? How ’bout letting a significant percentage of your property regenerate as successional habitat as well? It can and does make a difference!Beautiful cool-season grasses waving in the spring breeze. Meadows and hay fields can be managed to function as cool-season grasslands to provide nesting opportunities for many of the species we used to find down on the farm.
For many animals, an adequate shelter is paramount for their successful reproduction. Here’s a sample of some of the lower Susquehanna valley’s nest builders in action…
Many of our year-round resident bird species get a head start on the breeding season as cavity nesters. Some of these mated pairs use naturally occurring hollows, while still others take advantage of the voids left vacant by the more industrious previous occupants. Woodpeckers in particular are responsible for excavating many of the cavities that are later used as homes by a variety of birds and mammals to both rear their young and provide winter shelter. Pileated Woodpeckers, like other members of the family Picidae, have an almost mystic ability to locate diseased or insect-infested trees for selection as feeding and nesting sites. In this composite image, a pair is seen already working on a potential nursery during mid-January. After use by the woodpeckers, abandoned cavities of this size can become nesting sites for a variety of animals including bees, small owls, Great Crested Flycatchers, Wood Ducks, Hooded Mergansers, and squirrels.After use as a nesting site, a void excavated by Downy Woodpeckers can be occupied in subsequent years by chickadees, titmice, nuthatches, wrens, and other cavity-dwelling species.This Muskrat (Ondatra zibethicus) with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,……a process that can be repeated or renewed as necessary throughout the year.A Muskrat house in March. In the absence of leafy twigs, dried cattail stems will suffice. As it ages and decays, the house’s organic matter generates heat and makes an ideal location for turtles to deposit and hatch their eggs.Soon after Neotropical migrants begin arriving in the forests of the lower Susquehanna watershed, they begin constructing their nests. The majority of these species build “outdoors”, not within the confines of a tree cavity. Here we see a Wood Thrush with its bill full of dried leaves and other materials……ready to line the cup of its nest in the fork of a small understory tree.Though it often arrives during early April after spending the winter in sub-tropical and even some temperate climes, the Blue-gray Gnatcatcher must wait to start construction of its nest until many of the Neotropical migrants arrive in early May.You see, the Blue-gray Gnatcatcher relies on plenty of web-spinning spider activity to supply the construction materials it needs.A Blue-gray Gnatcatcher pulling apart a spider’s web on a warm May morning.Back at the nest site……the sticky spider webs bind together lichens and small bits of bark……to form a perfect little cup for the nesting Blue-gray Gnatcatchers.Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.Unfortunately for them, man-made litter can often seem to be the ideal material for binding the nest together. In an area only sporadically visited by anglers, this oriole had no trouble finding lots of monofilament fishing line, trash that can fatally entangle both adult and young birds of any species. If you see any fishing line at all, please pick it up and dispose of it properly.Always keep an eye open for fishing line and get it before the birds do!Like many other avians, male Brown-headed Cowbirds are now relentlessly pursuing females of their kind.All his effort is expended in an attempt to impress her and thus have a chance to mate.This male can indeed put all his energy into the courtship ritual because Brown-headed Cowbirds toil not to build a nest. They instead locate and “parasitize” the nests of a variety of other songbirds. After mating, the female will lay an egg in a host’s abode, often selecting a slightly smaller species like a Yellow Warbler or native sparrow as a suitable victim. If undetected, the egg will be incubated by the host species. Upon hatching, the larger cowbird nestling will dominate the brood, often ejecting the host’s young and/or eggs from the nest. The host parents then concentrate all their efforts to feed and fledge only the young cowbird.Watching and waiting. The Indigo Bunting evades cowbird parasitism by first recognizing the invader’s egg. They then either add a new layer of nest lining over it or they abandon the nest completely and construct a new one. Some patient buntings may delay their breeding cycle until after cowbird courting behavior ceases in coming weeks.
After repeatedly hearing the songs of these Neotropical migrants from among the foliage, we were finally able to get a look at them—but it required persistent effort.
Often found closer to the ground among shrubs and small trees, this Magnolia Warbler was a challenge to find in the upper reaches of a Chestnut Oak.Not far away, we spied this Yellow-rumped Warbler.Despite its status as probably the most common Neotropical songbird to nest in the deciduous woodlands of the lower Susquehanna valley, the Red-eyed Vireo is nevertheless notoriously difficult to locate among the leaves.The Ovenbird spends much of its time on the forest floor where it builds a domed oven-like nest.A fortunate observer may catch a glimpse of one perched in an understory shrub or small tree.But hearing the Ovenbird’s song, “teacher-teacher-teacher”, is frequently the only way to detect it.The Worm-eating Warbler nests in understory thickets on steep forested slopes. Its rich chipping song is often the only indication of its presence.Frequently easier to locate is the American Redstart, a Neotropical warbler that calls out its territory in damp woodlands from perches atop shrubs or among the lower limbs of trees.Warbling Vireos nest near streams or other bodies of water in large deciduous trees like this Northern Hackberry.Gray Catbirds are abundant in shrubby gardens and thickets. Most will come out of hiding to investigate disturbances like an observer making a pishing sound.Another inhabitant of brushy successional growth is the Common Yellowthroat. It too is curious and responds quickly to squeaky sounds made by human visitors to their home ground.The Yellow-breasted Chat is a bird of early successional growth. To establish and defend a breeding territory, this one adopted a perch along the edge of a woodlands overlooking a field in which prescribed fire was administered less than two months ago.Like the mockingbird and thrasher, the Yellow-breasted Chat is a mimic. Its song is a repertoire of the calls and songs of the bird species with which it may compete for food and nesting space. Unique to the chat is an occasional pause, whistle, or “chuck” note that creates a bridge between many of its song’s elements.
Sometimes we have to count ourselves lucky if we see just one in five, ten, or even twenty of the birds we hear in the cover of the forest canopy or thicket. But that’s what makes this time of year so rewarding for the dedicated observer. The more time you spend out there, the more you’ll eventually discover. See you afield!
A singing Scarlet Tanager lurking in the shade of an oak. Seeing is believing.
Neotropical birds are fairly well acquainted with repetitive periods of thundershowers. With that in mind, we decided not to waste this stormy Tuesday by remaining indoors.
Periods of rain need not put a damper on a day outdoors observing birds that wintered in a rain forest or other tropical environment.We hiked this utility right-of-way to the north of a heavy thunderstorm and found plenty of activity in the shrubby successional habitat there.Rain or shine, male Indigo Buntings were busy singing. All this exuberance is intended not only to establish and defend a nesting territory……but to attract the attention of a mate as well.Prior to the implementation of the intensive manicuring practices we see currently applied to most utility right-of-ways, shrubby thickets filled miles of these linear corridors to create a webbed network of early successional growth throughout the lower Susquehanna valley. Loss of this specialized habitat has led to the almost total elimination of the formerly common Blue-winged Warbler as a breeding species here.We found three male Blue-winged Warblers singing on territories in this bushy clearing where electric transmission lines pass over Third/Stony Mountain on State Game Lands 211.Their presence at this site is testament to the importance of maintaining corridors of quality successional habitat in the landscape.The Blue-winged Warbler is a Neotropical migrant with an easy-to-learn song. It’s a very simple, buzzy sounding “beeee-bzzz”.Another Neotropical species that nests in successional thickets is the Prairie Warbler (Setophaga discolor), seen here during one of this morning’s downpours.The Prairie Warbler can sometimes be found in stands of pioneer plants like Eastern Red Cedar on sites with barren soils or those that have been subjected to wildfire.The Hooded Warbler is fond of wooded thickets along the edge of forested land such as those in the Third/Stony Mountain utility right-of-way.The presence of a Mountain Laurel thicket also enhances a forest’s ability to host breeding Hooded Warblers.
We hope you enjoyed our walk in the rain as much as we did. If you venture out on a similar excursion, please remember this. The majority of the wild animals around us have busy lives, particularly at this time of year. Most don’t take a day off just because it rains—that includes ticks.
Be certain to check yourself for ticks, especially these very small Deer Ticks (Ixodes scapularis), also known as Black-legged Ticks. Deer Ticks are vigilantly looking for something to latch onto, even in the rain, and they can be vectors of Lyme disease. We found this adult female as a stowaway on the editor’s neck just before heading home from today’s stroll.
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 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.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.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.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.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.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.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.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.Hungry cormorants gather along the base of the dam where ascending fish congregate and become further disoriented by water turbulence.Fishing efforts here can bring great success to these accomplished piscivores.Latching onto an oversize Gizzard Shad can make you very popular with your peers.So popular that you may never have the opportunity to eat your lunch.Take it from this old bird: you’ve gotta swallow ’em fast, head first, tail and all.A Bald Eagle hauls off a 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.And yet another successful Bald Eagle calls out to its mate as it approaches its nest and hungry young.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”.This angler is reeling in a big one.A nice Channel Catfish weighed in at about six pounds and was released.This angler brought in yet another interesting catch.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.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.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.
Here’s a look at six native shrubs and trees you can find blooming along forest edges in the lower Susquehanna valley right now.
The Black Locust (Robinia pseudoacacia), a member of the pea or legume family (Fabaceae), can be a dominant pioneer plant of sunny successional habitats, particularly on poor soils. Nodules along its roots fix nitrogen to help facilitate the growth of the intermediate and climax species of trees and shrubs that replace the pioneers. Initially armed with protective spines to reduce browsing, the Black Locust’s branches become mostly thornless as the tree matures.The Pinxter Flower, also known as the Pink Azalea, is certainly a contender for our most spectacular native blossoming shrub;……this Spicebush Swallowtail seems to like it too.When in bloom, the Black Cherry is a common sight in regional woodlands. Often seen already covered with blossoms when young and shrub-like, many of these trees will continue flowering and producing fruit throughout the decades required to reach a mature height of 60 feet or more.The Blackhaw is an understory shrub preferential to sun-dappled areas beneath a break in the forest canopy. Pollinated flowers later produce clusters of blue-black berries for birds and other wildlife.It’s easy to overlook the flowers of the Common Pawpaw. By the time the leaves are fully emerged and casting shade, blooming time is over.Nowadays, the Flowering Dogwood is most frequently encountered as a transplanted cultivar in city and suburban landscapes. In the wild, it is sparingly distributed throughout the region’s deciduous forests. These slow-growing little trees produce bright red berries that are quickly seized by a variety of birds upon ripening in the fall.
Local old timers might remember hearing folklore that equates the northward advance of the blooming of the Flowering Dogwoods with the progress of the American Shad’s spring spawning run up the river. While this is hardly a scientific proclamation, it is likely predicated on what had been some rather consistent observation prior to the construction of the lower Susquehanna’s hydroelectric dams. In fact, we’ve found it to be a useful way to remind us that it’s time for a trip to the river shoreline below Conowingo Dam to witness signs of the spring fish migration each year. We’re headed that way now and will summarize our sightings for you in days to come.
Tree blossoms open in response to the presence of adequate moisture and exposure to the warming effects of sunshine. Shad ascend the Susquehanna to spawn in response to suitable river flow and increasing water temperature. Sun and rain in the appropriate proportions can often conspire to synchronize otherwise unrelated events. Hence, a Flowering Dogwood in bloom along the edge of a mature forest means it’s time to go check out the shad run.
Despite what seemed to be a chilly early spring, the bright green leaves that unfold to close the canopy of our deciduous forests were dense and casting shade by the last days of April. For northbound migrants, this fresh foliage provides the cover they need for foraging, resting, and, for those that will stick around to breed in the lower Susquehanna valley, nesting.
We recall many occasions when sparse foliage during the first days of May seemed to delay the big push of Neotropical species, but the seasonal arrival of these birds in 2025 is thus far mostly ahead of schedule. This absence of delay is due in part to the lushness of the oaks. Some stands have not only leafed out, but are finished flowering and have added up to 12 inches of new branch growth. We spent these early hours of May among the oaks. Here’s a look at the Neotropical migrants and other species we found…
Dozens of species of Neotropical warblers have arrived in the Lower Susquehanna River Watershed. Some will nest locally while others will continue along flight paths that will ultimately take them far to our north. We spotted this Cape May Warbler in the upper reaches of a Northern Red Oak feeding among its spent flowers. Its destination: the spruce forests of northern New England and Canada.Slightly larger than the warblers are the vireos, including this Yellow-throated Vireo that has arrived to nest in an oak-maple bottomland.Always a fan favorite, we found this marvelously tropical Baltimore Oriole among the foliage of a flowering White Oak.This young Red-tailed Hawk has survived its first winter. It appears to have learned from experience how to hunt from advantageous locations such as this Chestnut Oak along a utility right-of-way where prey may include numerous squirrels as well as mice and other small mammals.We were taking a break beneath this Pin Oak when suddenly an American Kestrel arrived to begin scolding a trespasser that was straying a bit too close to its nest;……the intruder, a Northern Harrier, soon took the hint and continued on its way.While among the oaks, it pays to check the understory where Neotropical thrushes including the Veery are arriving to fill the forests with their melodious songs.Following their nocturnal flights, the last of the season’s northbound White-throated Sparrows may presently be found spending the day in the cover of the oak woodland understory.
The movements of our migratory birds typically continue through much of the month of May. And peak numbers of Neotropical species often occur sometime during the second week of the month. But with habitat at the ready, favorable flight conditions could facilitate quick arrival and/or passage of the bulk of the remaining migrants during the coming week. You may want to venture out sooner rather than later—but watch your step!
The Mayapple, a native wildflower also known as the Mandrake, is now in bloom among the oak leaf litter.And the Canada Mayflower (Maianthemum canadense), a native species also known as Wild Lily-of-the-valley, is blooming in moist mixed-oak forests.At the edge of an oak-maple woodland, we found this lingering White-crowned Sparrow foraging among the leaf litter and fresh, shiny foliage of Poison Ivy. Songbirds can spend their days scratching the ground among these leaves of three. If you do it, you’ll be scratching something else, and you may need an ocean of calamine lotion to boot!
This petite Eastern Cottontail somehow found a path through weekend traffic to discover an abundant supply of lush green Indian Strawberry (Potentilla indica) leaves in the garden at susquehannawildlife.net headquarters. The widely naturalized Indian Strawberry, also known as Mock Strawberry, is native to Asia. It is most easily recognized by its bright yellow flowers which soon yield edible, but not very tasty, little red fruits. I wonder, might the berries be more palatable if dipped in a melted-down chocolate bunny? Food for thought, unless of course you have an aversion to hare in your romantic confections.
Here are five common forest flowers that the average visitor to these environs may easily overlook during an early April visit.
The flowers of the Skunk Cabbage, a native member of the arum family, are contained within a spadix which is partially hidden inside the mottled maroon spathe at the base of the plant. In late winter, the closed spathe generates its own heat to melt through frozen water and soils to make its appearance in streamside and spring-fed wooded wetlands, just ahead of the emergence of the large green leaves.Common Spicebush is a native flowering shrub of damp woodland understories. Later in the season, its foliage provides food for Spicebush Swallowtail caterpillars. Pollinated blossoms yield bright-red oblong berries relished by a variety of birds in fall and winter.The flowers of the indigenous Red Maple will soon generate the familiar helicopter-like winged seeds which readily distribute this native tree into new ground ranging from lowlands to the crests of our highest ridges.Coltsfoot (Tussilago farfara) is non-native wildflower of Eurasian origin. Reminding one at first glance of a dandelion, it is commonly seen blooming in disturbed areas of woodlands. Coltsfoot often grows where it has little competition from other plants, such as among the debris left behind due to snow plowing and grading along forest roads.Though not particularly abundant, the non-native Sweet Cherry, an escape from cultivation, is widespread in forests and woodlots throughout the lower Susquehanna valley. Sweet Cherry is believed to be an ancestor of the Sour Cherry (Prunus cerasus) and is frequently used as rootstock for orchard and garden varieties of this popular fruit. Sweet Cherry is often called “Wild Cherry”, a name also applied to the Black Cherry, a native tree which blooms later in the spring.
Be certain to get out and enjoy this year’s blooming seasons of our hundreds of varieties of flowering plants. But, particularly when it comes to native species,…
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.
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.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.Even as the fire reached its brief peak of intensity, we noticed birds already attracted to the site…Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.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 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.
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.
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.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.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.They seemed to favor gleaning seeds from among the lightly burned areas of the plot.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.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.
By late winter, sunshine and warming temperatures awaken the sleeping maples of the lower Susquehanna basin and the sap begins to flow. The new growing season is evident by the first days of spring when their swelling buds and flowers paint the drab gray canopy of deciduous woodlands with an overlying coat of red, orange, and maroon.
Red Maples, renowned for their vibrant autumn foliage, are just as conspicuous in the early spring landscape.For birds and mammals like this Eastern Gray Squirrel, the buds and flowers of maples mean relief from the diminished natural food supplies that helped them survive winter’s worst. The season of abundance has arrived and these animals instantly recognize this source of sweet, fresh energy, just in time for the breeding season. The flowers of maples, which later in the spring yield those familiar helicopter-like seeds, are an important early season source of energy for many species of bees and other pollinators.
Find a stand of Common Cattails in a marsh, a stormwater basin, or along a pond edge right now and you’re almost certain to find a male Red-winged Blackbird ……singing and displaying to defend a territory and attract a partner. Upon their arrival and selection of a mate, the brown-streaked females will weave well-hidden nests among the stems and leaves of these essential water-purifying wetland plants.
Our wildlife has been having a tough winter. The local species not only contend with cold and stormy weather, but they also need to find food and shelter in a landscape that we’ve rendered sterile of these essentials throughout much of the lower Susquehanna valley’s farmlands, suburbs, and cities.
Planting trees, shrubs, flowers, and grasses that benefit our animals can go a long way, often turning a ho-hum parcel of property into a privately owned oasis. Providing places for wildlife to feed, rest, and raise their young can help assure the survival of many of our indigenous species. With a little dedication, you can be liberated from the chore of manicuring a lawn and instead spend your time enjoying the birds, mammals, insects, and other creatures that will visit your custom-made habitat.
What makes some neighborhoods so appealing? It’s the foresight property owners had a half a century or more ago when they planted their lawns and gardens with a variety of sturdy, long-lived trees and shrubs. They’ve not only minimized the need for mowing grass, they’ve provided the present-day residents of their home with added thermal stability during both the blazing heat of summer and the chilling cold of winter.
Fortunately for us, our local county conservation districts are again conducting springtime tree sales offering a variety of native and beneficial cultivated plants at discount prices. Listed here are links to information on how to pre-order your plants for pickup in April. Click away to check out the species each county is offering in 2025!
Pickup on: Thursday, April 24, 2025 or Friday, April 25, 2025
During its 2025 tree seedling sale, the Cumberland County Conservation District is offering Northeast Native Wildflower seed mix for four dollars per ounce. One ounce plants approximately 200 square feet of bare soil. This is a Zebra Swallowtail visiting nectar-rich flowers during July of the first year after sowing this mix at a site along the Susquehanna.
Pickup on: Thursday, April 24, 2025 or Friday, April 25, 2025
Able to thrive in wet soils, Red-osier and Silky Dogwood shrubs are ideal plants for intercepting and polishing stormwater in swales, detention/retention basins, and rain gardens. With their crimson twigs in winter, they look great along borders among clusters of cedars, pines, spruces, and other evergreens. They make an excellent choice for soil stabilization along the shorelines of streams, ponds, and other bodies of water too. Buy a dozen or more to create a showy mass planting in your soggy spot.
The Franklin County Conservation District is offering American Elm seedlings in bundles of 25 for 36 dollars. Start them in pots for a couple of years to really get ’em going, then find places with damp soil and plenty of room to give ’em a try. During autumn, they look great in the company of spruces, white pines, and other large evergreens.
We purchased these Eastern White Pine, Norway Spruce, and Common Winterberry plants from the Lancaster County Conservation District Tree Sale about four years ago. They’re filling in as understory growth in the margins beneath some thirty-year-old Eastern Hemlocks to create dense cover for resident and visiting fauna at susquehannawildlife.net headquarters.
For 2025, the Lebanon County Conservation District is offering Dawn Redwood (Metasequoia glyptostroboides) trees in packs of ten for twelve dollars. Though native to Asia, these adaptable trees present little threat of naturalizing and have many positive attributes in a conservation planting. Given ample space, the Dawn Redwood, a relative of the sequoias, will rapidly grow to a towering giant. They create a particularly dramatic landscape feature when planted in clumps of three to five trees or more. With age, the trunks become stout and very sturdy. Don’t like raking? The finely divided deciduous foliage can be left where it falls in autumn. It usually disintegrates by spring to enrich the soil and promote more growth.The genus Metasequoia was first described in 1941 based upon fossils collected in Jurassic and earlier strata from widespread locations in the northern hemisphere. Metasequoia were believed extinct until just a few years later when a small number of living Dawn Redwoods were first discovered in southern China. Now distributed around the world for cultivation, direct descendants of this wild population of Metasequoia glyptostroboides are available for nearly anyone in a temperate climate to plant and grow to exceptional size. (National Park Service image)The Lebanon County Conservation District is also selling Bald Cypress trees. They’re offered in bundles of ten for ten dollars. These long-lived trees resemble the Dawn Redwood. Both are tolerant of damp ground, but the native Bald Cypress is the species to choose for placement along streams, in wetlands, and on other sites with standing water or saturated soil.Wildlife rich Bald Cypress swamps currently occur on the Atlantic Coastal Plain as far north as Sussex County, Delaware. Just to the south, they’re also found along Chesapeake Bay in areas that, during the last glacial maximum when sea level was 300 to 400 feet below today’s tide lines, were the Lower Susquehanna River Watershed in portions of present-day Maryland and Virginia. The northward post-glacial range extension of Bald Cypresses is now blocked by centuries of human intervention that has eliminated, isolated, or fragmented the wetland habitats where they could potentially become established. Why not lend them a hand? Plant a cypress swamp in your flood-prone bottomland. (National Park Service image by Andrew Bennett)
A privacy planting of sturdy, native Eastern White Pines and Northern Red Oaks thriving around the border of a parking area where they also provide shade from the sun and help infiltrate a share of the stormwater that would otherwise become runoff.This year, the York County Conservation District is offering a Showy Northeast Native Wildflower and Grass seed mix for $19.99 per quarter pound. Sure beats mowing!
If you live in Adams County, Pennsylvania, you may be eligible to receive free trees and shrubs for your property from the Adams County Planting Partnership (Adams County Conservation District and the Watershed Alliance of Adams County). These trees are provided by the Chesapeake Bay Foundation’s Keystone 10-Million Trees Partnership which aims to close a seven-year project in 2025 by realizing the goal of planting 10 million trees to protect streams by stabilizing soils, taking up nutrients, reducing stormwater runoff, and providing shade. If you own property located outside of Adams County, but still within the Chesapeake Bay Watershed (which includes all of the Susquehanna, Juniata, and Potomac River drainages), you still may have an opportunity to get involved. Contact your local county conservation district office or watershed organization for information.
As they mature, tree and shrub plantings along streams return pollution-controlling functions to floodplains and provide critical habitat for wildlife. These riparian buffers not only improve water quality for fisheries, they also create travel corridors that prevent terrestrial animal populations from becoming isolated.Do you own a parcel of streamside or wetland acreage that you’d like to set aside and plant for the benefit of wildlife and water quality? Contact your local county conservation district office and ask them to tell you about CREP (Conservation Reserve Enhancement Program) and other programs that may offer incentives including payment of all or a portion of the costs of plantings and other habitat improvements.
We hope you’re already shopping. Need help making your selections? Click on the “Trees, Shrubs, and Woody Vines” tab at the top of this page to check out Uncle Tyler Dyer’s leaf collection. He has most of the species labelled with their National Wetland Plant List Indicator Rating. You can consult these ratings to help find species suited to the soil moisture on your planting site(s). For example: if your site has sloped upland ground and/or the soils sometimes dry out in summer, select plants with a rating such as UPL or FACU. If your planting in soils that remain moist or wet, select plants with the OBL or FACW rating. Plants rated FAC are generally adaptable and can usually go either way, but may not thrive or survive under stressful conditions in extremely wet or dry soils.
NATIONAL WETLAND PLANT LIST INDICATOR RATING DEFINITIONS
OBL (Obligate Wetland Plants)—Almost always occur in wetlands.
FACW (Facultative Wetland Plants)—Usually occur in wetlands, but may occur in non-wetlands.
FAC (Facultative Wetland Plants)—Occur in wetlands and non-wetlands.
FACU (Facultative Upland Plants)—Usually occur in non-wetlands, but may occur in wetlands.
UPL (Upland Plants)—Almost never occur in wetlands.
Using these ratings, you might choose to plant Pin Oaks (FACW) and Swamp White Oaks (FACW) in your riparian buffer along a stream; Northern Red Oaks (FACU) and White Oaks (FACU) in the lawn or along the street, driveway, or parking area; and Chestnut Oaks (UPL) on your really dry hillside with shallow soil. Give it a try.
You may be on the verge of satisfying your appetite with chestnuts from an open fire, but this Red-bellied Woodpecker is just as pleased to retrieve a Shagbark Hickory nut from a hiding place among the tree’s cracks and crevices where it was stashed away earlier in the fall.
Each spring and fall, Purple Finches are regular migrants through the Lower Susquehanna River Watershed. Northbound movements usually peak in April and early May. During the summer, these birds nest primarily in cool coniferous forests to our north. Then, in October and November each year, they make another local appearance on their way to wintering grounds in the southeastern United States. A significant population of Purple Finches remains to our north through the colder months, inhabiting spruce-pine and mixed forests from the Great Lakes east through New England and southeastern Canada. This population can be irruptive, moving south in conspicuous numbers to escape inclement weather, food shortages, and other environmental conditions. Every few years, these irruptive birds can be found visiting suburbs, parks, and feeding stations—sometimes lingering in areas not often visited by Purple Finches. Right now, Purple Finches in flocks larger than those that moved through earlier in the fall are being seen throughout the lower Susquehanna valley. Snow and blustery weather to our north may be prompting these birds to shift south for a visit. Here are some looks at members of a gathering of more than four dozen Purple Finches we’ve been watching in Lebanon County this month…
Purple Finches are easily distinguished from House Finches by their notched tails, darker streaking, and well-defined facial markings. Though most frequently found in proximity to conifers, they also visit native deciduous trees and shrubs to snack on berries, seeds, and buds. Purple Finches can be particularly fond of maple, birch, poplar, sumac, and viburnum.Adult male Purple Finches are unmistakable in their wine-colored plumage.Purple Finches join a Dark-eyed Junco, a White-throated Sparrow, and a Black-capped Chickadee at a feeding station.Purple Finches eating black oil sunflower seed.A male Purple Finch in successional forest edge habitat consumes seeds from a dried stand of goldenrod.Purple Finches with juncos and Northern Cardinals.Purple Finches filling up on supplemental foods.
As the autumn bird migration draws to a close for 2024, we’re delighted to be finding five of our favorite visitors from the coniferous and mixed forests of Canada and the northernmost continental United States.
Yellow-bellied Sapsuckers drill evenly spaced holes which they repeatedly visit to harvest “sap” and the insects that become trapped therein. These surgically small excavations penetrate only the bark and the phloem, a shallow, spongy layer of the trunk that carries sugars from the leaves to other parts of the tree. Seldom do they puncture the thin, underlying cambium layer which protects the true sapwood. After healing, sapsucker holes leave linear rows of small scars which are sometimes still discernible decades after a bird’s final visit. This adult male will probably linger in the Lower Susquehanna River Watershed until colder weather renders the tree totally dormant, the flow of “sap” ebbs, and small insects become harder to find. Then he’ll make his way off toward southern forests of oak and pine for the remainder of the winter. Sapsuckers work their way north as sugary “sap” begins flowing again in the spring.The Hermit Thrush is another denizen of coniferous and mixed forests. In habitats with dense cover and sufficient food sources like fruit-bearing shrubs and vines, some will remain through the winter. The Hermit Thrush is the only spot-breasted thrush regularly seen in our region from November through March.Almost the size of a thrush, the largest of our native sparrows, the Fox Sparrow, is currently at the peak of its southbound migration. While taking a break from their nocturnal flights, some may stray from forest edges to visit suburban feeding stations. Most leave our area by mid-December, then begin returning north as early as mid-February.Not present every year, flocks of Pine Siskins are beginning to arrive in the lower Susquehanna region. They are currently most common along the mountain tops of the Ridge and Valley Province where they are feeding on the seeds of the Sweet Birch, a tree also known as Black Birch. Look for them around niger seed feeders and on the prickly seed balls of cultivated American Sweetgum, but don’t be surprised if they quickly pass us by to spend the winter on the Atlantic Coastal Plain to our south where this native tree grows in abundance.Since late October, Purple Finches have been widespread throughout the region. These female/juvenile male types are frequently being seen at feeders, particularly near woodlands and other areas with stands of conifers.Less frequently seen are the adult male Purple Finches in their raspberry-colored plumage. What a dandy.
While right now is the best time to get out and look for these species from the northern forests, any or all of them could linger into the winter months, particularly where the food supply is sufficient and conifers and other evergreens provide cover from the blustery weather.
During the past week, Uncle Tyler Dyer has been out searching for autumn leaves to add to his collection. One of the species he had not encountered in previous outings was the American Elm (Ulmus americana), so he made a special trip to see a rare mammoth specimen in a small neighborhood park (Park Place) along Chestnut Street between 5th and Quince Streets in Lebanon, Pennsylvania.
Possibly the largest and oldest remaining American Elm in the lower Susquehanna watershed, the Park Place tree in Lebanon exceeds 60 feet in height and may be more than 300 years of age. In the nearly one hundred years since Dutch elm disease (DED) first began killing elms in eastern North America, this tree has been spared the fatal effects of the infection. DED is caused by several species of microfungi (Ophiostoma ulmi, O. himal-ulmi, and O. novo-ulmi) spread by numerous bark beetle (Curculionidae) species. As early as 1928, infected beetles arrived in the United States from the Netherlands among shipments of logs.Leaves of the American Elm.
There’s still time to get out and see autumn foliage. With warmer weather upon us—at least temporarily—it’s a good time to go for a stroll. Who knows, you might find some spectacular leaves like these collected by Uncle Ty earlier this week. All were found adorning native plants!
Winged Sumac (Rhus copallina), a small native tree. In case you’re wondering, it’s not poisonous.Black Chokeberry (Photinia melanocarpa), a native shrub also known as Aronia. It produces black-colored fruits in summer.Red-osier Dogwood (Cornus sericea), a shrub that prefers wet or damp soils. It yields white fruits.Maple-leafed Viburnum (Viburnum acerifolium), a native shrub of upland forest understories.Highbush Blueberry (Vaccinium corymbosum), a native shrub and the source of many cultivated forms of the popular fruit.To identify your finds, be certain to click the “Trees, Shrubs, and Woody Vines” tab at the top of this page to check out Uncle Ty’s extensive collection.
During your foray to view the colorful foliage of the autumn landscape, a little effort will reveal much more than meets the eye of the casual observer.
Don’t just stand there like a bump on a log, go for a stroll, watch your step, and have a look around. There’s a lot to see out there!The dense understory of this forest on Blue Mountain consists almost exclusively of Witch-hazel (Hamamelis virginiana).Witch-hazel is unique among our native flowering shrubs; it blooms in autumn.Until we experience a heavy frost, some of our most beautiful butterflies, including this Common Buckeye, remain active along forest edges.An Eastern Tailed Blue.A Pearl Crescent.A Variegated Fritillary.A Painted Lady.The arrival of large numbers of Yellow-rumped Warblers heralds the transition to movements of migrants that will spend the colder months in temperate climates like ours instead of continuing on to the tropics. In winter, small numbers of “yellow-rumps” sometimes linger in the Lower Susquehanna River Watershed, as long as a supply of wild berries is readily available.The Palm Warbler, a persistent “tail wagger”, is another late-season migrant that occasionally spends the winter. The migration of these drab “Western Palm Warblers” will be followed in coming weeks by the more yellowish “Eastern Palm Warblers” of the eastern third of the species’ breeding range in Canada.White-throated Sparrows are southbound and easily observed right now. Many will remain along our brushy forest edges for winter.Another native sparrow, the familiar Dark-eyed Junco, is now arriving.The Yellow-bellied Sapsucker is a secretive migratory woodpecker that is currently moving through the region on its way to southern pine forests for the winter. Juveniles like this one in the lower right remain close to their parents during migration and continue to beg for food.The Pileated Woodpecker is a resident species in our mature forests and woodlands. We were showered by “sawdust” as we watched this one dismantling a rotted dead tree while searching for beetle grubs and other invertebrates.You may see Eastern Bluebirds year-round in the lower Susquehanna valley, but many are migratory. A southbound push is currently transiting our area.Mix your leaf watching with hawk watching by visiting a ridgetop vista like this one at Boyd Big Tree Preserve Conservation Area on Blue Mountain north of Harrisburg and you can double your pleasure.In addition to spectacular foliage, you stand a good chance of seeing an inquisitive Common Raven……or a migrating Red-tailed Hawk that gives you a good scream as it passes by……or a majestic Bald Eagle.You may even double your fun by seeing two Common Ravens……or a couple of migrating Red-tailed Hawks……or a pair of Bald Eagles passing thru.
You too can experience the joys of walking and chewing gum at the same time, so grab your field glasses, your camera, and your jacket, then spend lots of time outdoors this fall. You can see all of this and much more.
Don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page to help you find a place to see both fall foliage and migrating birds of prey in coming weeks. And click the “Trees, Shrubs, and Woody Vines” tab to find a photo guide that can help you identify the autumn leaves you encounter during your outings.
Here today, gone tomorrow. This Ruby-throated Hummingbird lingered around the numerous tubular flowers in the headquarters garden until near darkness last evening. It was last seen entering the cover provided by our Eastern Hemlocks where it presumably spent the night. Bright and early this morning, it made repeated visits to Mexican Cigar and this Bat-faced Cuphea to re-energize before resuming its long voyage to the tropics for winter. This marks the third consecutive year we’ve been visited by late-season hummingbirds during the first week of October. All were attracted to our nectar-rich plantings.
Bathed in glowing sunshine, a very large fallout of migrating Neotropical songbirds enlivened the forest edge atop Second Mountain in northern Lebanon County, Pennsylvania, this morning. While last night’s flight was widespread beneath a dome of atmospheric high pressure covering the Mid-Atlantic States, this is a look at some of the 500 -1,000 migrants observed feeding on insects and other natural foods at just this single location.
As the composition of the nightly flights begins to transition to species that start their migration later in the season, numbers of birds like the Blackpoll Warbler (top) are beginning to rival those of the heretofore very common Black-throated Green Warbler (bottom).A Blackpoll Warbler.The Bay-breasted Warbler, another common species found among the fallout flock.The Tennessee Warbler was today’s most abundant migrant with at least 200 birds seen moving among the other species.A newly arrived Tennessee Warbler at sunrise.A Tennessee Warbler snatches breakfast.The Magnolia Warbler was another common find among today’s migrants.A Magnolia Warbler.A Nashville Warbler among tangles of Mile-a-minute Weed.A Nashville Warbler.Black-throated Blue Warbler.An adult male Black-throated Blue Warbler.An acrobatic Northern Parula.Blackburnian Warblers continue their southerly trek.An American Redstart.A Chestnut-sided Warbler feeding on Mile-a-minute Weed berries.A Cape May Warbler.A handsome adult male Cape May Warbler.A Swainson’s Thrush.Scarlet Tanagers continue to work their way south through the Lower Susquehanna River Watershed.A composite image of an uncommon find, a large-headed Olive-sided Flycatcher seen perched atop a dead tree snag.A brief encounter with a Philadelphia Vireo, another uncommon species.A Blue-headed Vireo, typically the last of its genus to move south in the fall, put in a welcome appearance among the hundreds of migrants.A favorite diurnal migrant, the Ruby-throated Hummingbird, was seen feeding on flowers that grew from the remains of garden waste dumped illegally along the mountain road last autumn.
Many of the observers at the Second Mountain Hawk Watch commented that this morning’s fallout was by far the best they had seen anywhere in the region during recent years. Others believed it to be the best they had ever seen. It was indeed less like a “wave” of migrants and more like a “tsunami”. Choosing a good viewing location and being there at the right time can improve your chances of seeing a spectacle like this. The good news is, it looks like another big flight is currently underway, so finding a forest edge on a ridgetop or along a utility right-of-way just might pay off for you early tomorrow morning.
Nocturnal migrating birds, a southwest-bound flight down the ridges of central Pennsylvania as indicated by Doppler radar between 10:30 and 11:30 PM EDT on September 11, 2024. (NOAA/National Weather Service image)
Clear, cool nights have provided ideal flight conditions for nocturnal Neotropical migrants and other southbound birds throughout the week. Fix yourself a drink and a little snack, then sit down and enjoy this set of photographs that includes just some of the species we found during sunrise feeding frenzies atop several of the Lower Susquehanna River Watershed’s ridges. Hurry up, because here they come…
A Black-throated Green Warbler.The Black-throated Green Warbler was perhaps the most frequently identified treetop warbler during the most recent four mornings.A Black-throated Green Warbler with a unique variation in the crown plumage.The Blackburnian Warbler was another plentiful species.Cape May Warblers have an affinity for conifers like this Eastern White Pine.But when traveling in mixed flocks with other migrants, Cape May Warblers can also be found feeding in the crown foliage of deciduous trees.This adult Tennessee Warbler appears to be adorned in a very worn set of plumage……and its traveling companion looks like it’s overdue for a new set of feathers as well.Like the Tennessee Warbler, the Nashville Warbler was common among mixed flocks.A Nashville Warbler atop a Black Cherry.This Chestnut-sided Warbler was one of several found among the more common species of migrants.A Chestnut-sided Warbler.We were lucky enough to spot this male Chestnut-sided Warbler sporting his namesake flank feathers.A Black-and-white Warbler uses its nuthatch-like feeding behavior to search the tree bark for edible invertebrates.To see the Common Yellowthroat, one must cease looking upward into the high canopy and instead give the aching neck a rest by peering into the low vegetation at the forest edge.While checking the low growth, keep an eye open for other migrants among the shrubs and tangles. This Magnolia Warbler glows in the rays of a rising sun as it searches for a meal after a long night of travel.Here we found a perky little House Wren.Back in the middle and upper reaches of the trees, we find what has been by far the most numerous of the flycatchers seen during our visits to fallout sunrises. Eastern Wood-Pewees are appearing in very good numbers and can be seen quarreling and battling for hunting perches from which they are ambushing flying insects.An Eastern Wood-Pewee fiercely defending its hunting perch.An Eastern Wood-Pewee.The numbers of migrating Least Flycatchers and other members of the genus Empidonax may be reaching their seasonal peak this week.Scarlet Tanagers are currently a common find following nocturnal flights.A Scarlet Tanager peers down from the top of a Red Maple.Did you hear a loud squeak in the treetops? It could be a southbound Rose-breasted Grosbeak stopping by for the day.A Rose-breasted Grosbeak in a dead tree snag.The Neotropical thrushes are beginning to move south now as well. We found this newly arrived Swainson’s Thrush at Rocky Ridge County Park in York County during sunrise this morning.Not surprisingly, the Red-eyed Vireo is one of the most numerous of the migrants seen feeding in the deciduous canopy following a nocturnal flight event. It’s not at all unusual to see dozens filing the trees around a ridgetop overlook or along a forest edge. Be certain to check these congregations carefully, especially the groups of birds feeding in the lower branches of tall timber or in the tops of smaller trees. This week we found……several hungry Yellow-throated Vireos arriving after nocturnal flights,……and a Philadelphia Vireo (Vireo philadelphicus) at the hawkwatch at Rocky Ridge County Park in York County.Though not a Neotropical migrant, the easier-heard-than-seen Red-breasted Nuthatch is beginning to wander south into the lower Susquehanna region. Most of these birds will eventually continue on to the pine forests of the southern United States for winter, but a few could remain to become seasonal visitors at feeding stations.Ruby-throated Hummingbirds are on the move; their migration to the tropics is well underway and nearing its peak. Ruby-throats are diurnal migrants that do a majority of their flying during the hours of daylight. The notable exception: the nighttime portion of the long southbound flight some of the birds make to cross the Gulf of Mexico.The Red-headed Woodpecker is another diurnal migrant. This denizen of temperate climates is currently beginning to move to its wintering grounds, an area that extends from the latitudes of the lower Susquehanna south to the Gulf of Mexico and central Texas.A juvenile Red-headed Woodpecker during a brief pit stop.The flights of roving bands of masked Cedar Waxwings continue. Their numbers appear to be an improvement over those of 2023.At regional hawk-counting stations, observers are seeing more Broad-winged Hawks and other species beginning to move through.The frequency of Broad-winged Hawks passing the lookouts one at a time is giving way to the occurrence of larger and larger “kettling” groups that search out thermal updrafts to save energy while migrating. By mid-September each of these “kettles” can include one hundred birds or more. On the peak days, the daily Broad-winged Hawk totals can reach one thousand or more.A Broad-winged Hawk soaring to gain lift from a thermal updraft above a hawkwatch lookout.
The migration is by no means over; it has only just begun. So plan to visit a local hawkwatch or other suitable ridgetop in coming weeks. Arrive early (between 7 and 8 AM) to catch a glimpse of a nocturnal migrant fallout, then stay through the day to see the hundreds, maybe even thousands, of Broad-winged Hawks and other diurnal raptors that will pass by. It’s an experience you won’t forget.
A Broad-winged Hawk gliding away to the southwest.
Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing south through the lower Susquehanna valley in coming months. And don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you.
More birds are on the way. Here’s a look at this evening’s liftoff of nocturnal migrants detected by National Weather Service Radar in State College, Pennsylvania. (NOAA/National Weather Service Doppler Radar image)
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…
Pennsylvania Game Commission crews administering prescribed fire on a grassland demonstration site back on March 16.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.The scorched, lifeless remains of small trees and shrubs indicate that that goal was met.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.By August, the site is a haven for native plants and animals.The burn has promoted the growth and late-summer bloom of fire-tolerant native wildflowers and warm-season grasses……including Indiangrass,……Big Bluestem……Thin-leaved Coneflower (Rudbeckia triloba), a plant also known as Brown-eyed Susan,……and Joe-pye Weed, a plant butterflies find irresistible.Eastern Tiger Swallowtail collecting nectar from Joe-pye Weed.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.By August, native grassland plants in the prescribed fire area were already providing an abundance of seeds for birds including this American Goldfinch.For larger birds like turkeys and pheasants, an abundance of Carolina Grasshoppers are providing a protein-dense food source in managed grasslands.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…
Bobolinks nested both in areas subjected to controlled burns……and in hay fields where mowing was delayed until the nesting season, including the fledging process, was completed earlier this month.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 at a site subjected to prescribed fire earlier in the spring.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 at a site not subjected to any recent fire activity.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.
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.
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.
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.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.
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 (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.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.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.
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).
It’s hard to believe, but for almost two months now, sandpipers, plovers, and terns have been filtering south through the Lower Susquehanna River Watershed on their way to the Atlantic coastline as they complete the first leg of their long autumn migration—a journey that will take some species all the way to the far reaches of the South American continent for winter.
Migrating Caspian Terns and an Osprey take a break on a lower Susquehanna valley gravel bar.
As August draws to a close, these early birds are being joined by widespread nocturnal flights of Neotropical migrants—those species, primarily songbirds, on their way to wintering grounds which lie exclusively south of the continental United States.
To catch a glimpse of these night-flying avians, your best bet may be to position yourself on the crest of a ridge or along a linear break in the forest such as a utility right-of-way where waves of warblers, vireos, flycatchers, and other Neotropical passerines sometimes feed on invertebrates after making landfall at daybreak. Pick a place where the trees are bathed in the warm light of the rising sun and be there by 7 A.M. E.D.T. The activity can be tremendous, but it usually ends between 8 and 9.
One of more than half a dozen Red-eyed Vireos seen during a daybreak fallout at Second Mountain Hawkwatch in Lebanon County earlier this week.During sunrise, a just-arrived Blackburnian Warbler checks the foliage of a ridgetop Red Maple for insects.A Least Flycatcher quietly searches the shrubby growth along the forest edge for a morning meal.A Black-and-white Warbler in the first hour of sunlight after a big nocturnal flight.A Scarlet Tanager having a look around. This individual and other migrating birds may be here for a few days before moving on.A Black-throated Green Warbler in a treetop glowing with the light of sunrise.A hungry Chestnut-sided Warbler inspects limbs, leaves, and twigs looking for nourishment after an all-night flight.
Diurnal migrants, birds that make their movements during the daylight hours, are ramping up their flights now as well. Broad-winged Hawks, Bald Eagles, and falcons are currently being tallied at hawk-counting stations throughout the northeast. Many of those lookouts are seeing Ruby-throated Hummingbirds, swallows, and other daytime migrants too.
While many diurnal migrants gather in flocks as a method of defense against predators, Broad-winged Hawks congregate as a reconnaissance measure. Not waiting around for strong autumn winds to be deflected upwards by the region’s numerous ridges, these Neotropical birds migrate early enough in the season to rely upon thermal updrafts from sun-heated surfaces to provide lift, gain altitude, and save energy during their long trip. By traveling in groups, there are collectively able to better locate and utilize rising air columns as they progress southwesterly along their route. Broad-winged Hawks travel to Central and South America for winter. Their numbers in the Lower Susquehanna River Watershed will peak during the third week of September.Many American Kestrels transit our area in August and early September, a time coinciding with flights of migratory dragonflies, insects upon which they and another falcon, the Merlin, frequently prey.Chimney Swifts are fast-flying diurnal migrants. They are beginning to congregate into larger groups in preparation for their departure. Some are already on the move.Cedar Waxwings are currently being seen in roving flocks throughout the region. Their migration is less of a point-to-point flight and more of a continuous wandering in search of berries and other wild foods.Not everyone is yet ready to go. American Goldfinches are still in the midst of their nesting cycle and won’t begin leaving until the young are on their own and colorful adult males like this one are beginning to molt into their drab winter plumage.
Autumn migration flights are an ever-changing process, with different species peaking at different times throughout the season. In these months just after the nesting season, each of these species is more numerous than at any other time of the year. And of course, the more often we as observers get out and have a look, the more of them we’ll see.
Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing through the lower Susquehanna valley this fall. Nearly four months of autumn hawk migration flights lie ahead, so don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you, then stop by for a visit or two. See you there!
A large nightfall liftoff of nocturnal migrating birds is shown here on this evening’s State College, Pennsylvania, Doppler Radar base velocity loop. Returns indicating birds moving toward the radar site (the white dot in the center of the color mass) are shown in green, and those indicating birds moving away are indicated in red. This is a big flight headed generally in a south-southwest direction. (NOAA/National Weather Service Doppler Radar image)
In the forests and woodlots of the lower Susquehanna watershed, the Black Gum, also known as the Black Tupelo, is always the first of our native trees to pop with autumn color. Its crimson leaves glow in an otherwise green landscape to help lure hungry birds including waxwings, American Robins, and Pileated Woodpeckers to its soon-to-be-ripe berries. The seeds contained in the fruit are thus well-distributed as a by-product of this avian feast. While not among the most massive of our trees, the Black Gum can live for over five hundred years, an age not exceeded by any other non-clonal indigenous flowering plant.
Do you recall our “Photo of the Day” from seven months ago…
Here’s something to look forward to in the new year. The good citizens of East Donegal Township in Lancaster County have partnered with Alliance for the Chesapeake Bay to establish an extensive wildflower meadow on what had been a mowed field of turf grass at Riverside Park in the Susquehanna floodplain near Marietta. As the photo shows, the lawn plants have been eliminated in preparation for seeding with a diverse assortment of native grasses and wildflowers to provide habitat for birds and pollinators including butterflies, bees, and other insects. Once established, the meadow’s extensive vegetative growth will help reduce stormwater runoff by better infiltrating rainfall to recharge the aquifer. During flood events, the plantings will provide soil stabilization and increase the ability of the acreage to uptake nutrients, thus reducing the negative impact of major storms on the quality of water in the river and in Chesapeake Bay. Check the project’s progress by stopping by from time to time in 2024!
Well, here’s what that site looks like today…
The wildflowers, thousands of them, are now in bloom!Black-eyed Susan and Blue Vervain (Verbena hastata) dominate the assortment currently in flower.
And there are pollinating insects galore, most notably butterflies…
A Cabbage White collecting nectar on Blue Vervain.A Clouded or Orange Sulphur among the grasses in the meadow.A Silver-spotted Skipper.The Least Skipper is our tiniest butterfly.The Little Glassywing (Vernia verna), this one feeding on vervain nectar, deposits its eggs on Purpletop grass, which then functions as the host plant for this butterfly’s larvae.A Summer Azure (Celastrina neglecta) feeding on the nectar of a Black-eyed Susan.A Common Buckeye on a “Gloriosa Daisy”, a showy, large-flowered cultivar of Black-eyed Susan.A Red-winged Blackbird with a caterpillar found among the meadow’s lush growth.An Eastern Tiger Swallowtail on Blue Vervain. Nearby Yellow (Tulip) Poplars and other trees serve as host plants for this butterfly’s larvae.The black morph of the Eastern Tiger Swallowtail shows subdued shading in the wings that closely resembles the brilliant color patterns of the more familiar yellow form.The Sachem, this one visiting a Black-eyed Susan, is a variable species with a range that normally lies south of the 40th parallel, the line of latitude that intersects the Susquehanna in the area of the Conejohela Flats at Washington Boro.A Sachem visiting the blooms of Oxeye sunflower. During recent weeks, scorching winds from the south and southwest have transported an abundance of these vagrant skippers into the lower Susquehanna valley and beyond.A male Sachem approaching the bloom of a “Gloriosa Daisy”. Miles north of the 40th parallel, wandering Sachems are currently the most numerous of the butterflies at the Riverfront Park wildflower meadow.Here and there among the meadow’s plantings we noticed one of our favorites starting to flower, the Partridge Pea.Partridge Pea happens to be a host plant for another vagrant from the south, the big, lime-yellow Cloudless Sulphur. We saw at least half a dozen patrolling the meadow.The stars of the show are the Zebra Swallowtails, gorgeous butterflies that rely on stands of native Common Paw-paw trees in the river floodplain to host their eggs and larvae.The red-white-and-blue underside of a Zebra Swallowtail.WOW!
Why on earth would anyone waste their time, energy, and money mowing grass when they could have this? Won’t you please consider committing graminicide this fall? That’s right, kill that lawn—at least the majority of it. Then visit the Ernst Seed website, buy some “Native Northeast Wildlflower Mix” and/or other blends, and get your meadow planted in time for the 2025 growing season. Just think of all the new kinds of native plants and animals you’ll be seeing. It could change your life as well as theirs.
A Snowberry Clearwing (Hemaris diffinis), more commonly known as a hummingbird moth, visits the flowers of Blue Vervain in the Riverfront Park wildflower meadow.
Resilient to the pressures of flooding, ice scour, drought, and oft times really poor water quality, Water Willow (Dianthera americana, formerly Justicia americana) is the most common herbaceous plant on the Susquehanna’s non-forested alluvial islands. Yet, few know this native wildflower by name or reputation.
Pure stands of emergent Water Willow endure at times brutal conditions on non-forested islands in the Susquenanna.Alluvial deposits of sand, clay, gravel, and silt create ideal substrate for mats of Water Willow along shorelines of the Susquehanna and its larger tributaries. Provided the loose substrate remains moist, this emergent thrives even when water levels retreat during periods of dry weather. The woody plant in the background, the native Black Willow (Salix nigra), shares similar soil preferences but is found growing on slightly higher ground as a non-emergent tree or shrub. It is a member of the willow family (Salicaceae).In bloom now, the orchid-like flower of the Water Willow is a quick giveaway that it is not a close relative of the willow trees but is instead a member of the acanthus family (Acanthaceae) and is allied with the genus Ruellia, the wild petunias.
The spring of 2024 has been very kind to our beds of Water Willow. Rainfall in the Susquehanna watershed has been frequent enough to maintain river levels just high enough to keep the roots of the plants wet. During the interludes in storm activity, dry spells have rolled back any threat of flooding on the river’s main stem, thus eliminating chances of submerging the plants in muddy water and preventing the sun from keeping them warm, happy, and flowering early. Thundershowers throughout the basin earlier this week have now raised the river a few inches to inundate the base of the plants and make mats of Water Willow favorable places for newly hatched fry and other young fish to take refuge while they grow. Here’s a look…
The Spottail Shiner (Notropis hudsonius) is a common native minnow of the Susquehanna. This juvenile was found among several dozen small fish taking refuge in the cover of Water Willow below Conewago Falls.The Mimic Shiner (Notropis volucellus) is generally regarded to be a native transplant from the Mississippi drainage that has become established in the Susquehanna and many of its tributaries, possibly after introduction by way of bait buckets. However, the fish tends to be very fragile and dies quickly upon handling, so its use and transport as a bait species may be impractical. The Mimic Shiner is very common in around Conewago Falls.A juvenile Mimic Shiner less than one inch in length found among flooded Water Willow below Conewago Falls earlier this week.One of about a dozen juvenile Quillbacks (Carpiodes cyprinus) found in Water Willow just below Conewago Falls. For spawning, local populations of this compact native species of carpsucker favor the gravel-bottomed pools among the Jurassic-Triassic boulders of the falls’ pothole rocks. Probably hatched within the last eight weeks, this specimen was just one inch long.As summer progresses, stands of emergent Water Willow begin to expand their size by sending out rhizomes. Increasing numbers of small fish like this Spotfin/Satinfin Shiner (Cyprinella species) concentrate in the cover of the thickening vegetation.The importance of these patches of emergent wildflowers (sounds weird, doesn’t it?) is demonstrated by the numbers of fish gathered within their underwater forest of stems and leaves by summertime.To protect them from burial by silt and to prevent them from being swept away by current, spawning Spotfin/Satinfin Shiners deposit their eggs in crevices of submerged rocks and wood, often in or near mats of Water Willow. Males guard the eggs until hatching. The fry must then take shelter among boulders, cobble, and plant cover. Note the breeding-condition male in the upper right.Panfish like this non-native Green Sunfish (Lepomis cyanellus) will often choose nesting sites in deeper water adjacent to beds of Water Willow, particularly if submerged growth like this Water Stargrass adds to the availability of cover for their young after hatching.Smallmouth Bass gather in a pool adjacent to a Water Willow-covered island. These non-native predators rely on beds of these indigenous plants to provide habitat for their young, then, after spawning, lurk in the waters surrounding them to ambush less-than-vigilant minnows and other victims.
By now you’ve come to appreciate the importance of Water Willow to the sustainability of our populations of fish and other aquatic life. Like similar habitat features that reduce sediment runoff and nutrient pollution, undisturbed stands of terrestrial, emergent, and submerged native plant species are essential to the viability of our freshwater food webs.
The minuscule Long-legged Fly (Condylostylus species) is a predatory consumer of soft-bodied invertebrates. In the headquarters garden, we found this individual and others scurrying around on the leaves of Common Milkweed where they may be seeking to gobble up infesting aphids.
Yesterday, while photographing damselflies on a rehabilitated segment of a warmwater lower Susquehanna valley stream, we noticed some oddly chunky small fish gathered on the surface of a pool along the shoreline.
Perched damselflies and some sort of robust little fish feeding nearby.
Upon further inspection, they appeared to be fingerlings of some type of sunfish or bass. Time for a closer look.
At just one inch in length, these juvenile Largemouth Bass (Micropterus salmoides) are already showing signs of the dark lateral stripe that so easily identifies the adult fish.Adult Largemouth Bass began spawning among nearby beds of Spatterdock and other emergent and submerged aquatic vegetation about one month ago, just as water temperatures stabilized to a minimum of the low sixties for several days and nights. Each female can lay thousands of eggs. Only those that are successfully fertilized by the attending male have a chance to hatch.Largemouth Bass eggs can hatch as soon as ten days after being deposited in the nest by the female and fertilized by the male. The fry linger in the nest for another week consuming the nutrition contained in their attached yolk sac.The juvenile fish are then ready to leave the nest and begin feeding on zooplankton.Young largemouths often gather in schools to feed in waters near their birthplace. As they grow, they soon begin consuming small invertebrates and tiny fish. But for young bass, the hazards are many. These juveniles can become victims of a host of predatory insects, crayfish, piscivorous birds, and bigger fish. Then too, Largemouth Bass, like most other species of fishes, are cannibalistic and will consume others of their own kind. Of the thousands of eggs produced by a mating pair, natural selection determines which, if any, of their progeny will survive to reproduce and sustain their genetic line.
In the Lower Susquehanna River Watershed, the Largemouth Bass is an introduced species, a native transplant from the Mississippi watershed and Atlantic Slope drainages south of the Chesapeake.
The bright-red flower buds of the Ninebark (Physocarpus opulifolius) precede clusters of white blooms that will, in coming weeks, attract a variety of butterflies and other pollinators to this indigenous shrub. Its peeling bark and colorful deciduous leaves attract interest throughout the year. In the lower Susquehanna watershed, Ninebark is most frequently found growing along stream banks. It will often thrive on steep slopes with moist soils, so is useful as an erosion control species as well. To add it to your refuge’s landscape, look for it at nurseries that stock native plants. Once there, you’ll find a variety of cultivars that are sure to satisfy even the fussiest of gardeners.
During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest. Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.
The conspicuous nest of the Eastern Tent Caterpillar (Malacosoma americanum), a native species of moth. The first instar of the larval caterpillars hatch in early spring from egg masses laid on the limbs of the host tree by an adult female moth during the previous spring. Soon after they begin feeding on the host tree’s first tender shoots, these tiny, seldom-noticed larvae start communal construction of a silk tent to act as a shelter and greenhouse-like solar collector that will both provide protection from the elements and expedite their growth.The familiar last instar of the Eastern Tent Caterpillar is the most consumptive stage of the animal’s life. After feeding in the treetops, they will descend to the ground and seek a sheltered location to pupate. Adult moths emerge in several weeks to take to the air, mate, and produce eggs to be deposited on a host tree for hatching next year. The favorite host tree in forests of the Lower Susquehanna River Watershed: native Black Cherry.
Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars. All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.
The Yellow-throated Vireo nests, feeds, and spends the majority of its time feeding among canopy foliage.The Eastern Wood-Pewee is a flycatcher found in mature woodlands. It feeds not only among the limbs and leaves, but is an aerial predator as well.The Northern Parula nests in mature forests along rivers and on mountainsides, particularly where mature trees are draped with thick vines.The Hooded Warbler (Setophaga citrina) is found among thick understory growth on forested slopes.The Ovenbird builds a domed, oven-like nest on the ground and forages in the canopy.The Kentucky Warbler (Geothlypis formosa) nests in woodland undergrowth, often near steep, forested slopes.The Worm-eating Warbler (Helmitheros vermivorum) nests among woody understory growth on forested hillsides.The Scarlet Tanager is often difficult to observe because of its affinity for the canopy of mature forest trees.
In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent. There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard. One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young. That could very well be true—but consider timing.
Already Gone- By the time Neotropical migrants arrive in our area, the larval stages of the Eastern Tent Caterpillar’s life cycle are already coming to an end. The nests that these native insects constructed to capture the energy of the springtime sun have allowed the larvae to exit and browse foliage when conditions were suitable, then return for shelter when they were not. While inside, the larvae could move among the chambers of their structure to find locations with a temperature that best suited their needs. Therein the solar heating and communal warmth sped up digestion and growth.Eastern Tent Caterpillar larvae are now in their bristly final-instar stage and the majority have already moved to the ground to each seek a place to pupate and metamorphose into an adult moth. Arboreal Neotropical birds have scarcely had a chance to feed upon them, and ground-feeding species seem to lack any temptation. As for the adult moths, they fly only at night and live for just one day, offering little in the way of food for aerial, arboreal, or ground-feeding birds.Having left arboreal environs, Eastern Tent Caterpillar larvae are now food for ground-feeding birds like our resident Wild Turkeys. They need only get past the bristly hairs on the caterpillar’s back and the foul taste that may result from its limited diet of cyanogenic Black Cherry leaves.The arboreal Yellow-billed Cuckoo (seen here) and its close relative the Black-billed Cuckoo (Coccyzus erythropthalmus) are the two species of birds in our area known to regularly feed on bristly tent caterpillars. But having just arrived from the tropics to nest, they’ll need to rely on other insects and their larvae as sources of food for their young.Final-instar Eastern Tent Caterpillars often defoliate Black Cherry trees before moving to the ground to pupate. Their timing allows them to feed on the fresh foliage while it is still young and tender, and to largely avoid becoming food for the waves of Neotropical birds that arrive in the lower Susquehanna basin in May.
So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars? Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.
An American Redstart singing in a Black Cherry. Unlike others in the vicinity, this tree nestled among several very large Eastern White Pines showed no signs of tent caterpillar activity. It may be that for one reason or another, no adult female moth deposited her eggs on this particular tree. During our visits, Black Cherry was but one of the diverse variety of native trees and shrubs found growing on the sloping topography that created attractive habitat for the nesting birds we found. We happened to notice that a majority, but not all, of those Black Cherry trees were impacted by Eastern Tent Caterpillars.The end of the Eastern Tent Caterpillar’s larval surge may spell the end of their nests for the year, but it’s not the end for the Black Cherry and other host trees in the Prunus (cherry) and Malus (apple) genera. Because it’s still early in the season, they have plenty of time to re-leaf and many will still flower and produce fruit. Those flowers and foliage will attract numerous other insects (including pollinators) that benefit breeding birds.The Blue-winged Warbler inhabits shrubby breaks in the forest such as this utility right-of-way where Black Cherry trees have sprouted after their seeds arrived in waste deposited by fruit-eating (frugivorous) birds. Already attractive to a variety of insectivores, these openings soon lure egg-laying Eastern Tent Caterpillar moths to the cherry trees growing therein. Even in dense forest, a small clearing created by a cluster of dead trees makes good bird habitat and will sooner or later be visited by fruit-eating species that will inadvertently sow seeds of Black Cherry, starting yet another stand of host trees for Eastern Tent Caterpillars. It’s the gap in the forest that often attracts the birds, some of which plant the host trees, which sometimes entice Eastern Tent Caterpillar moths to lay their eggs.Adapt and Reuse- A Red-eyed Vireo visits an Eastern Tent Caterpillar nest……and ignores the few remaining occupants that could easily be seized to instead collect silk to reinforce its own nest.
Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site. For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat. For us, they can be great places to see and hear colorful birds.
Our Lucky Break- This Scarlet Tanager descended from the treetops to feed on spiders in a small forest clearing.
