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.
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)
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)
As week-old snow and ice slowly disappears from the Lower Susquehanna River Watershed landscape, we ventured out to see what might be lurking in the dense clouds of fog that for more than two days now have accompanied a mid-winter warm spell.
After freezing to a slushy consistency earlier this week, the Susquehanna is already beginning to thaw. Below the York Haven Dam at Conewago Falls, the water is open and ice-free.On frozen man-made lakes and ponds, geese and ducks like these Mallards and American Wigeon are presently concentrated around small pockets of open water.During the past ten days, American Robin numbers have exploded throughout the lower Susquehanna valley. The majority of these birds may be a mix of both those coming south to escape the late onset of wintry conditions to our north and those inching north into our region as early spring migrants.The January thaw has melted the snow from lawns and fields to provide thousands of visiting robins with a chance to forage for earthworms.A visit by this young Cooper’s Hawk to the susquehannnawildlife.net headquarters garden sent songbirds scrambling……but did nothing to unnerve our resident Eastern Gray Squirrels,……which promptly went into tail-waving mode to advertise their presence.But earlier in the week, when heavy snow cover in the rural areas surrounding our urbanized neighborhood made it difficult for rodent-eating raptors to find food, we received brief visits from both a Red-tailed Hawk……and this young Red-shouldered Hawk, an uncommon bird of prey most often found in wet woods and other lowlands.To escape notice during visits by these larger raptors, our squirrels remained motionless and commenced performance of their best bump-on-a-log impressions.Unimpressed, each of our visiting buteos remained for just a few minutes before moving on in search of more favorable hunting grounds and prey.As snow melted and exposed bare ground in fields of early successional growth, we encountered……a flock of White-crowned Sparrows, most in first-winter plumage……and at least a dozen American Tree Sparrows. During the twentieth century, these handsome songbirds were regular winter visitors to the lower Susquehanna region. During recent decades, they’ve become increasingly more difficult to find. Currently, moderate numbers appear to be arriving to escape harsher weather to our north.What could be more appropriate on a foggy, gray evening than finding a “gray ghost” (adult male Northern Harrier) patrolling the fields in search of mice and voles.
If scenes of a January thaw begin to awaken your hopes and aspirations for all things spring, then you’ll appreciate this pair of closing photographs…
The maroon-red flower buds of Silver Maples are beginning to swell. And woodpeckers including Pileated Woodpeckers are beginning to drum, a timber-pounding behavior they use to establish breeding territories in habitats with suitable sites for cavity nesting.In wet soil surrounding spring seeps and streams, Skunk Cabbage is rising through the leaf litter to herald the coming of a new season. Spring must surely be just around the corner.
Just as bare ground along a plowed road attracts birds in an otherwise snow-covered landscape, a receding river or large stream can provide the same benefit to hungry avians looking for food following a winter storm.
Here is a small sample of some of the species seen during a brief stop along the Susquehanna earlier this week.
Along vegetated edges of the Susquehanna and its tributaries, the Song Sparrow is ubiquitous in its search for small seeds and other foods. As the river recedes from the effects of this month’s rains, the shoreline is left bare of more recently deposited snow cover. Song Sparrows and other birds are attracted to streamside corridors of frost-free ground to find sufficient consumables for supplying enough energy to survive the long cold nights of winter.Thousands of American Robins have been widespread throughout the lower Susquehanna valley during the past week. Due to the mild weather during this late fall and early winter, some may still be in the process of working their way south. Currently, many robins are concentrated along the river shoreline where receding water has exposed unfrozen soils to provide these birds with opportunities for finding earthworms (Lumbricidae) and other annelids.This Golden-crowned Kinglet was observed searching the trees and shrubs along the Susquehanna shoreline for tiny insects and spiders. Temperatures above the bare ground along the receding river can be a few degrees higher than in surrounding snow-covered areas, thus improving the chances of finding active prey among the trunks and limbs of the riparian forest.Not far from the kinglet, a Brown Creeper is seen searching the bark of a Silver Maple (Acer saccharinum) for wintering insects, as well as their eggs and larvae. Spiders in all their life stages are a favorite too.American Pipits not only inhabit farm fields during the winter months, they are quite fond of bare ground along the Susquehanna. Seen quite easily along a strip of pebbly shoreline exposed by receding water, these birds will often escape notice when spending time on mid-river gravel and sand bars during periods of low flow.An American Pipit on a bitterly cold afternoon along the Susquehanna.
Where should you go this weekend to see vibrantly colored foliage in our region? Where are there eye-popping displays of reds, oranges, yellows, and greens without so much brown and gray? The answer is Michaux State Forest on South Mountain in Adams, Cumberland, and Franklin Counties.
South Mountain is the northern extension of the Blue Ridge Section of the Ridge and Valley Province in Pennsylvania. Michaux State Forest includes much of the wooded land on South Mountain. Within or adjacent to its borders are located four state parks: King’s Gap Environmental Education Center, Pine Grove Furnace State Park, Caledonia State Park, and Mont Alto State Park. The vast network of trails on these state lands includes the Appalachian Trail, which remains in the mountainous Blue Ridge Section all the way to its southern terminus in Georgia.
In Pennsylvania, the forested highlands of the Blue Ridge Section of the Ridge and Valley Province are known as South Mountain. Much of South Mountain lies within the boundaries of Michaux State Forest. Stars indicate the locations of 1) King’s Gap Environmental Education Center, 2) Pine Grove Furnace State Park, 3) Caledonia State Park, and 4) Mont Alto State Park. A drive on US 30 between Gettysburg and Chambersburg will take you right through Michaux State Forest along an east to west axis while a scenic northbound or southbound trip along PA 233 will bring you in proximity to each of the state parks located therein. (Base image from NASA Earth Observatory Collection)
If you want a closeup look at the many species of trees found in Michaux State Forest, and you want them to be labeled so you know what they are, a stop at the Pennsylvania State University’s Mont Alto arboretum is a must. Located next door to Mont Alto State Park along PA 233, the Arboretum at Penn State Mont Alto covers the entire campus. Planting began on Arbor Day in 1905 shortly after establishment of the Pennsylvania State Forest Academy at the site in 1903. Back then, the state’s “forests” were in the process of regeneration after nineteenth-century clear cutting. These harvests balded the landscape and left behind the combustible waste which fueled the frequent wildfires that plagued reforestation efforts for more than half a century. The academy educated future foresters on the skills needed to regrow and manage the state’s woodlands.
Online resources can help you plan your visit to the Arboretum at Penn State Mont Alto. More than 800 trees on the campus are numbered with small blue tags. The “List of arboretum trees by Tag Number” can be downloaded to tell you the species or variety of each. The interactive map provides the locations of individual trees plotted by tag number while the Grove Map displays the locations of groups of trees on the campus categorized by region of origin. A Founder’s Tree Map will help you find some of the oldest specimens in the collection and a Commemorative Tree Map will help you find dedicated trees. There is also a species list of the common and scientific tree names.
The Yellow Buckeye (Aesculus flava) is a tree found in the forests of the Blue Ridge Section of the Ridge and Valley Province in West Virginia, Virginia, North Carolina and Georgia. You can see it in Pennsylvania by visiting the collection of trees in the Arboretum at Penn State Mont Alto.The American Chestnut can be difficult to find due to the impact of chestnut blight, but you can see it in the Arboretum at Penn State Mont Alto.Shagbark Hickory is a common tree in the forests of South Mountain.The Sweet Cherry (Prunus avium), a native of Europe, is naturalized throughout eastern and south-central Pennsylvania and is one of the more than 150 species of trees in the arboretum’s collection.Sweet Birch (Betula lenta) foliage is particularly bright yellow on South Mountain this autumn. It really “pops” against the backdrop of the evergreen Eastern White Pines and Eastern Hemlocks. During less-than-ideal years, Sweet Birch leaves can subtly transition from green to drab brown without much fanfare before falling.You might have a difficult time finding a Common Persimmon (Diospyros virginiana) growing wild in Pennsylvania, but you can find it in the Arboretum at Penn State Mont Alto.
The autumn leaves will be falling fast, so make it a point this weekend to check out the show on South Mountain.
What’s all this buzz about bees? And what’s a hymanopteran? Well, let’s see.
Hymanoptera—our bees, wasps, hornets and ants—are generally considered to be our most evolved insects. Some form complex social colonies. Others lead solitary lives. Many are essential pollinators of flowering plants, including cultivars that provide food for people around the world. There are those with stingers for disabling prey and defending themselves and their nests. And then there are those without stingers. The predatory species are frequently regarded to be the most significant biological controls of the insects that might otherwise become destructive pests. The vast majority of the Hymanoptera show no aggression toward humans, a demeanor that is seldom reciprocated.
Late summer and early autumn is a critical time for the Hymanoptera. Most species are at their peak of abundance during this time of year, but many of the adult insects face certain death with the coming of freezing weather. Those that will perish are busy, either individually or as members of a colony, creating shelter and gathering food to nourish the larvae that will repopulate the environs with a new generation of adults next year. Without abundant sources of protein and carbohydrates, these efforts can quickly fail. Protein is stored for use by the larval insects upon hatching from their eggs. Because the eggs are typically deposited in a cell directly upon the cache of protein, the larvae can begin feeding and growing immediately. To provide energy for collecting protein and nesting materials, and in some cases excavating nest chambers, Hymanoptera seek out sources of carbohydrates. Species that remain active during cold weather must store up enough of a carbohydrate reserve to make it through the winter. Honey Bees make honey for this purpose. As you are about to see, members of this suborder rely predominately upon pollen or insect prey for protein, and upon nectar and/or honeydew for carbohydrates.
We’ve assembled here a collection of images and some short commentary describing nearly two dozen kinds of Hymanoptera found in the Lower Susquehanna River Watershed, the majority photographed as they busily collected provisions during recent weeks. Let’s see what some of these fascinating hymanopterans are up to…
SOLITARY WASPS
A Great Black Wasp on goldenrod (Solidago species). Like other solitary wasps, a female Great Black Wasp will sting and paralyze a host insect upon which she’ll deposit her eggs. After hatching, the larvae will begin consuming the host’s body as a source of protein. The parasitized insects are often katydids or grasshoppers.A Great Black Wasp feeding on nectar, a source of carbohydrates. Unlike social bees and wasps, solitary wasps are equipped with a stinger solely used for immobilizing prey, not defending a nest. They are therefore quite docile and pose little threat to humans.A Great Black Wasp powdered with pollen. Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.A female Thread-waisted wasp (Ammophilia species, probably A. nigricans) drags a paralyzed caterpillar to her excavated nest where she’ll deposit an egg on the body. After hatching, the larval wasp will feed on the disabled caterpillar. The protein will enable the larvae to grow, pupate, and later emerge as an adult wasp.The female Eastern Cicada Killer (Sphecius speciosus) excavates an underground nest with branch tunnels connecting a dozen chambers or more. As the common name suggests, the female wasp paralyzes a cicada, then makes a strenuous effort to fly and drag it back to the nest for placement in a cell. Each male wasp egg is deposited upon just one immobilized cicada, but a female egg is provided with a cache of several cicadas to provide adequate protein for growth to a larger size. Nest cells are sealed with soil, then the larvae hatch in just a couple of days. Within about two weeks, they have consumed the cicada protein and are fully grown. Wrapped in a cocoon, they spend the winter in the nest, then pupate in the spring before emerging as a new generation of adults.The Black-and-yellow Mud Dauber (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.A Black-and-yellow Mud Dauber at nest.The Pipe Organ Mud Dauber builds this elaborate nest in which their eggs and paralyzed spiders are deposited in cells sealed with mud partitions. After consuming the spiders, the larvae pupate, overwinter, then emerge from their cells as adults during the following spring. To escape the protection of the nest, the new generation of adults bore through the mud walls. Adult Pipe Organ Mud Daubers resemble the Great Black Wasp, but have a white or yellow distal segment on their rear legs resembling a pair of light-colored socks.A closeup of the previous image with the lengths of the nest tubes compressed to show four scavenger flies (Miltogramminae), possibly two species, that have invaded this Pipe Organ Mud Dauber nest. Scavenger flies are kleptoparasites that victimize various solitary bees and wasps, depositing larvae directly into the host species’ nest cells to consume the protein cache stored therein.
CUCKOO WASPS
Cuckoo Wasps (Chrysididae), also known as Emerald Wasps, parasitize the nests of other species of wasps. Females lay their eggs inside the host’s nest, then flee the scene. Upon hatching, larval Cuckoo Wasps feed on stockpiles of prey intended for the host species’ offspring. Like the adult mud daubers that have already matured and departed this nest by digging a hole through the wall of the cell within which they were hatched, the metallic green Cuckoo Wasp in the upper left has just emerged in much the same way.
SWEAT BEES
A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).Sweat Bees (Lasioglossum species) visit human skin to lick up the electrolytes left behind by evaporating perspiration.Sweat Bees in the genus Lasioglossum demonstrate various social behaviors ranging from species that are solitary nesters to those that create colonies with work forces ranging in size from as few as four to as many as hundreds of bees. Some Lasioglossum practice kleptoparasitism, while others are quite accomplished foragers.A female Augochlorine Green Sweat Bee (Augochlorini) collecting nectar on White Snakeroot. Notice the pollen “baskets” on the rear leg.An Augochlorine Green Sweat Bee (Augochlorini). Sweat bees nest in subterranean cavities and in hollowed out sections of trees.A copper-colored Augochlorine Green Sweat Bee (Augochlorini) collecting nectar and dusted with pollen.
LEAFCUTTER AND MASON BEES
A Leafcutter Bee (Megachile species). Like Mason Bees, female Mason Bees deposit each of their eggs on a “pollen loaf” within an individual cell inside a preexisting tunnel-like cavity in wood, stone, or in the ground. Unlike Mason Bees, female Leafcutter Bees cut a circular piece of leaf to create each of the cells in their nest. After hatching, the larval bee feeds on the pollen loaf, pupates, then emerges from the shelter of the nest to start a new generation, usually during the following year.A Leafcutter Bee (Megachile species) visiting Wild Bergamot. Female Leafcutter and Mason Bees lack pollen “baskets” on their rear legs but instead have pollen “brushes” on the underside of the abdomen to gather the protein they need to create a “pollen loaf” for each nest cell.A Leafcutter Bee (Megachile species) collecting nectar from White Snakeroot.A Mason Bee (Osmia species) emerging from a nest in spring. Mason Bees create nesting cells within preexisting cavities in wood, stone, and other other supporting structures. Within the nest cavity, each egg is deposited atop a cache of pollen and nectar, a pollen loaf, then enclosed behind a partition of mud. The female Mason Bee will usually repeat this process until an entire cavity is filled with cells. During the following spring, a new generation of adult Mason Bees digs its way through the cell walls to emerge and repeat the process. These bees readily use paper straws or holes drilled in blocks of wood for nesting.A mason bee nest box with holes drilled into blocks of wood.Mason Bees seal each cell and the outer end of their nest cavity with mud. These outer nest cells can been parasitized by a variety of wasps. Here, the outer cell of a Mason Bee nest has been victimized by a tiny chalcid wasp (looks like another one to the lower left). Several species of female chalcid wasps (native Monodontomerus species or non-native Pteromalus venustus) enlarge weak points in the outer partition of a mason bee nest, then sting and paralyze the larval bee inside before depositing their eggs. Within the cell. the wasp larvae consume the larval Mason Bee and the “pollen loaf” provided for its growth. These same parasitic wasps prey upon Leafcutter Bees as well.
BUMBLE BEES, CARPENTER BEES, HONEY BEES, AND DIGGER BEES
A Common Eastern Bumble Bee (Bombus impatiens) collecting nectar and pollen on goldenrod. Bumble bees are our sole native group of social bees. Their wax nests are built in a burrow or other shelter. The eggs are deposited in cells along with a supply of pollen for nourishing the larvae upon hatching. Honey is stored in “honey pots” within the nest. New queens are produced along with male bees during the late-summer and fall. Only the new generation of fertilized queens survive the winter to lay eggs and produce workers to construct a new nest.A pair of Common Eastern Bumble Bees collecting nectar and becoming dusted with pollen. Their fuzzy coats and semi-warm-blooded metabolism allows them to be active in cooler weather than is tolerated by other bees.Flowering plants including the Great Rhododendron find success attracting pollinators to their reproductive blossoms by offering carbohydrate-rich nectar to insects like this Eastern Bumble Bee. The yellow spots on the flower’s upper petal help to guide visitors toward their sweet treat.An Eastern Carpenter Bee feeding on goldenrod nectar. Compare the almost hairless abdomen to that of the bumble bees. Carpenter bees are semi-social insects. Females lay their eggs in cells within galleries bored into wood. These nests are completed with great precision, avoiding creation of any second entrance by mistakenly breaching the outer surface of the excavated wood. Each egg/larvae is provided with a supply of protein-rich pollen. Males often hover outside their mate’s nest to prevent competing males from entering the area.A worker Honey Bee, a female member of a sisterhood of foragers from a nearby hive, visits goldenrod alongside Common Eastern Bumble Bees. Honey Bees were brought to North America during the 1620s, the earliest years of the trans-Atlantic migration of European colonists, to pollinate cultivated plants and to provide a reliable source of honey and beeswax. Within the Honey Bee’s social structure, the queen of each hive lays the eggs to produce the female worker bees. Once each year, male drones are produced along with a new generation of queens.In nature, Honey Bees build hives in tree cavities. Recently, this colony constructed a hive in a screech owl nest box at susquehannawildlife.net headquarters. To provide protein for the hatching larvae, worker bees collect pollen and deposit it within the hexagonal cells of the vertically aligned beeswax combs. After an egg is deposited upon the pollen cache, each cell is sealed with more beeswax. Young females tend these nest combs before maturing and becoming foraging worker bees.In apiculture, Honey Bees are raised in man-made hives. This Pennsylvania Association of Beekeepers display gives visitors to the Pennsylvania Farm Show in Harrisburg a look at the inner workings of a live bee hive. Nectar collected by worker bees is turned into honey to provide the supply of carbohydrates needed to fuel the colony through the winter. Note the honeycombs on the glass.A possible Small Carpenter Bee (Ceratina species) visiting White Snakeroot. Small Carpenter Bees nest inside hollow stems and twigs. Some species are eusocial, with a queen’s daughters and sisters sharing responsibility for finding food and rearing the young. Females overwinter inside a one of the excavated stems and begin a new nest there in the spring.A Digger Bee (possibly Melissodes species) with “pollen baskets” full of pollen collected from nearby flowers. Digger Bees in the genus Melissodes are often known as the Long-horned Bees. These social insects excavate underground nests and many species practice communal living.
SCOLIID WASPS
The Two-spotted Scoliid Wasp (Scolia dubia), also known as the Blue-winged Scoliid Wasp, is most frequently observed feeding on nectar. Scoliid wasps are solitary nesters, though they may assemble into groups while visiting flowers. They often ignore the presence of humans and are seldom disturbed by their presence. Females seek out the burrowing grubs of beetles including the Green June Bug (Cotinis nitida) and possibly the Japanese Beetle. After stinging a grub to paralyze it, the wasp will deposit her egg on its body, then bury it. Upon hatching, the larval wasp will feed on the grub for nourishment as it grows.Don’t like having your watermelon overrun by Green June Bugs while you’re eating? Then you ought to go out of your way to be nice to the Two-spotted Scoliid Wasp.The Double-banded Scoliid (Scolia bicincta) parasitizes beetle larvae as hosts for its larvae. For carbohydrates it relishes flower nectar.
PAPER WASPS
A Northern Paper Wasp (Polistes fuscatus). Paper wasps prey upon numerous garden pests, particularly caterpillars, to collect protein. Though they are social insects equipped with stingers to subdue their victims and defend their nests, paper wasps are surprisingly docile.A Northern Paper Wasp (Polistes fuscatus) feeding on nectar from a goldenrod flower.A Northern Paper Wasp harvesting wood pulp from the side of a mason bee nest box at susquehannawildlife.net headquarters. The pulp is chewed in the wasp’s saliva to create the paper used to construct the colony’s open-cell nest.Common Paper Wasps (Polistes exclamans), also known as Guinea Paper Wasps, at their open-cell nest. This and the nests of most other paper wasps are suspended on a filament or a pedicle. Many paper wasps can excrete an ant repellent on this section of the nest in an effort to prevent invasion. Like many other social hymenopterans, a defending wasp can secrete a pheromone venom during the stinging process to warn the colony of danger at the nest. In winter, Common Paper Wasps seek shelter in stumps and other locations to hibernate.The European Paper Wasp (Polistes dominula) is a non-native species which builds nests in man-made structures including bird houses. To collect protein, they prey on a wide selection of insects and other invertebrates. As such, European Paper Wasps are widespread and successful here in North America.
YELLOWJACKETS AND HORNETS
An Eastern Yellowjacket feeding on lanternfly honeydew. Eastern Yellowjackets derive much of their success from being generalists, collecting carbohydrates from nearly any sweet source, natural or man made. They are quite fond of ripe fruits, flower nectar, and sugary snacks and drinks, especially soda. Protein for nourishing their larvae is derived from the wide variety invertebrates upon which they prey and from carrion. These foods are chewed into a paste form in preparation for placement into the brood cells.A subterranean colony of Eastern Yellowjackets is started anew each spring by a young queen that has survived winter hibernation in diapause, a state of interrupted development. She constructs the new nest’s first cells using pulp made by chewing rotting wood. The first brood of workers scales up construction while the queen continues producing eggs. At the nest, these social insects will viciously attack anyone or anything perceived to be a threat, so give them their space and leave them alone. Many yellowjacket infestations of homes and other buildings are the work of non-native German Yellowjacket (Vespula germanica) [not shown], an invasive species that constructs paper nests in void spaces including walls and attics.Yellowjackets may be moody and aggressive, but they do fall victim to a number of predators. A Robber Fly (Promachus species) has taken down and is devouring this Eastern Yellowjacket.A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew on a Tree-of-heaven (Ailanthus altissima). In the absence of nectar-producing flowers, many bees, yellowjackets, and hornets have turned to the invasive lanternfly and Ailanthus combo to turn the sun’s energy into the carbohydrates they need. For protein, they prey upon spiders, flies, caterpillars, and a variety of other insects.To create paper for nest construction, this Bald-faced Hornet is collecting wood pulp from the surface of a weathered picnic table. Away from the nest, these hornets demonstrate a calm, carefree demeanor and can be closely observed.A Bald-faced Hornet nest in a pine tree. These hives are strictly temporary. Within the nest, a generation of drones (males) and new queens are produced late each year. These wasps leave the colony to mate. With the arrival of freezing weather, all inhabitants within the nest, including the old queen, perish, as do the drones that departed to breed. Only the new queens survive winter hibernation to propagate the next generation of wasps, starting with the workers needed to construct a fresh nest and reestablish the colony.Did you ever get the feeling you’re being watched? Don’t go messing around with Bald-faced Hornet nests. The occupants therein, like other social bees, wasps, and hornets, are equipped with stingers and venom for defending their colony. This is an adaptation that has developed over time to assure the survival of populations of these insects. Think about it this way, a solitary wasp that loses a nest loses only their individual brood of offspring. There is minimal impact on the wider local population of such insects. Conversely, a social wasp or hornet that loses a nest loses an entire colony, possibly negating the benefits of their cooperative behavior and threatening the survival of the species. Insects that cooperate to build societies for survival can be more vulnerable to the catastrophic impacts of certain circumstances like disease, weather, and invasion of their colonies. Therefore, natural selection has provided them with contingencies for these dangers, for example, the instinct to construct protective shelters and the adaptation of stingers and venom for defense against intruders and would-be predators. Oh, and by the way, the Bald-faced Hornet can spray venom, often aiming for the eyes, so keep your distance.European Hornets (Vespa crabro), an introduced species, are predatory on a variety of flying insects for protein. For carbohydrates they are attracted to sweets like this lanternfly honeydew on Tree-of-heaven.European Hornets constructing a paper nest in a tree cavity.
POTTER WASPS
A potter wasp (Eumenes species), probably a Fraternal Potter Wasp (E. fraternus), hovering near a European Paper Wasp on Partridge Pea. The female potter wasp builds a small mud nest resembling a tiny clay pot. One of her eggs is inserted and left hanging on a thin thread. Then a paralyzed caterpillar is deposited as a source of protein to nourish the larva upon hatching. Lastly, the pot is sealed with a lid made of wet mud. Upon maturing, the new generation of adult wasps perform a pottery breaking to emerge and take flight.
ANTS
Field Ants (Formica species, possibly Formica pallidefulva) clear the entrance to their underground nest. Field ants are eusocial insects, they work in concert to build, maintain, and defend the nest, rear young, and find food. There is no social caste system. Field Ants are predators and scavengers when collecting protein. For carbohydrates they often rely on the honeydew produced by aphids. As a method of improving and sustaining the production of honeydew, some ant species will tend colonies of aphids by moving the younger individuals from depleted portions of plants to more healthy tissue. Field Ant nests contain chambers used for a variety of functions including raising young and storing food. Some nests include multiple queens and some colonies consist of more than one nest. Ants in the genus Formica are weaponized; they can spray formic acid to repel intruders and defend their colony.
We hope this brief but fascinating look at some of our more common bees, wasps, hornets, and ants has provided the reader with an appreciation for the complexity with which their food webs and ecology have developed over time. It should be no great mystery why bees and other insects, particularly native species, are becoming scarce or absent in areas of the Lower Susquehanna River Watershed where the landscape is paved, hyper-cultivated, sprayed, mowed, and devoid of native vegetation, particularly nectar-producing plants. Late-summer and autumn can be an especially difficult time for hymanopterans seeking the sources of proteins and carbohydrates needed to complete preparations for next year’s generations of these valuable insects. An absence of these staples during this critical time of year quickly diminishes the diversity of species and begins to tear at the fabric of the food web. This degradation of a regional ecosystem can have unforeseen impacts that become increasingly widespread and in many cases permanent.
How can anyone be surprised by the absence of bees and other pollinators in farmland? Manicured and cultivated ground offers little in the way of year-round shelter and food sources for insects and other wildlife.This savanna-like habitat on a south-facing slope provides the abundance of nectar-producing, pollen-rich wildflowers needed to nourish a diverse population of insects including bees, wasps, hornets, and ants. Goldenrods, asters, and White Snakeroot are some of their late-season favorites.
Editor’s Note: No bees, wasp, hornets, or ants were harmed during this production. Neither was the editor swarmed, attacked, or stung. Remember, don’t panic, just observe.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York, NY.
Have you purchased your 2023-2024 Federal Duck Stamp? Nearly every penny of the 25 dollars you spend for a duck stamp goes toward habitat acquisition and improvements for waterfowl and the hundreds of other animal species that use wetlands for breeding, feeding, and as migration stopover points. Duck stamps aren’t just for hunters, purchasers get free admission to National Wildlife Refuges all over the United States. So do something good for conservation—stop by your local post office and get your Federal Duck Stamp.
Your Federal Duck Stamp is your admission ticket for entry into many of the country’s National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.
Still not convinced that a Federal Duck Stamp is worth the money? Well then, follow along as we take a photo tour of Bombay Hook National Wildlife Refuge. Numbers of southbound shorebirds are on the rise in the refuge’s saltwater marshes and freshwater pools, so we timed a visit earlier this week to coincide with a late-morning high tide.
This pair of Northern Bobwhite, a species now extirpated from the Lower Susquehanna River Watershed and the rest of Pennsylvania, escorted us into the refuge. At Bombay Hook, they don’t waste your money mowing grass. Instead, a mosaic of warm-season grasses and early successional growth creates ideal habitat for Northern Bobwhite and other wildlife.Twice each day, high tide inundates mudflats in the saltwater tidal marshes at Bombay Hook prompting shorebirds to move into the four man-made freshwater pools. Birds there can often be observed at close range. The auto tour route through the refuge primarily follows a path atop the dikes that create these freshwater pools. Morning light is best when viewing birds on the freshwater side of the road, late-afternoon light is best for observing birds on the tidal saltwater side.A Great Blue Heron at high tide on the edge of a tidal creek that borders Bombay Hook’s tour route at Raymond Pool.Semipalmated Sandpipers stream into Raymond Pool to escape the rising tide in the salt marsh.More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.Two more Short-billed Dowitchers on the way in.Recent rains have flooded some of the mudflats in Bombay Hook’s freshwater pools. During our visit, birds were often clustered in areas where bare ground was exposed or where water was shallow enough to feed. Here, Short-billed Dowitchers in the foreground wade in deeper water to probe the bottom while Semipalmated Sandpipers arrive to feed along the pool’s edge. Mallards, American Avocets, and egrets are gathered on the shore.More Short-billed Dowitchers arriving to feed in Raymond Pool.Hundreds of Semipalmated Sandpipers gathered in shallow water where mudflats are usually exposed during mid-summer in Raymond Pool.Hundreds of Semipalmated Sandpipers, several Short-billed Dowitchers, and some Forster’s Terns (Sterna forsteri) crowd onto a mud bar at Bear Swamp Pool.A zoomed-in view of the previous image showing a tightly packed crowd of Semipalmated Sandpipers, Forster’s Terns, and a Short-billed Dowitcher (upper left).Short-billed Dowitchers wading to feed in the unusually high waters of Raymond Pool.Short-billed Dowitchers, American Avocets, and a Snowy Egret in Raymond Pool. A single Stilt Sandpiper (Calidris himantopus) can been seen flying near the top of the flock of dowitchers just below the egret.Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.American Avocets probe the muddy bottom of Raymond Pool.Among these Short-billed Dowitchers, the second bird from the bottom is a Dunlin. This sandpiper, still in breeding plumage, is a little bit early. Many migrating Dunlin linger at Bombay Hook into October and even November.This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.Lesser Yellowlegs at Bear Swamp Pool.Lesser Yellowlegs at Bear Swamp PoolA Greater Yellowlegs at Bear Swamp Pool.A Caspian Tern patrolling Raymond Pool.The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.This dome-shaped Marsh Wren nest is supported by the stems of Saltwater Cordgrass (Sporobolus alterniflorus), a plant also known as Smooth Cordgrass. High tide licks at the roots of the cordgrass supporting the temporary domicile.By far the most common dragonfly at Bombay Hook is the Seaside Dragonlet (Erythrodiplax berenice). It is our only dragonfly able to breed in saltwater. Seaside Dragonlets are in constant view along the impoundment dikes in the refuge.Red-winged Blackbirds are still nesting at Bombay Hook, probably tending a second brood.Look up! A migrating Bobolink passes over the dike at Shearness Pool.Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.A pair of Trumpeter Swans (Cygnus buccinator) as seen from the observation tower at Shearness Pool. Unlike gregarious Tundra and Mute Swans, pairs of Trumpeter Swans prefer to nest alone, one pair to a pond, lake, or sluggish stretch of river. The range of these enormous birds was restricted to western North America and their numbers were believed to be as low as 70 birds during the early twentieth century. An isolated population consisting of several thousand birds was discovered in a remote area of Alaska during the 1930s allowing conservation practices to protect and restore their numbers. Trumpeter Swans are slowly repopulating scattered east coast locations following recent re-introduction into suitable habitats in the Great Lakes region.A Great Egret prowling Shearness Pool.A Snowy Egret in Bear Swamp Pool.Wood Ducks in Bear Swamp Pool.A Bombay Hook N.W.R. specialty, a Black-necked Stilt and young at Bear Swamp Pool.
As the tide recedes, shorebirds leave the freshwater pools to begin feeding on the vast mudflats exposed within the saltwater marshes. Most birds are far from view, but that won’t stop a dedicated observer from finding other spectacular creatures on the bay side of the tour route road.
Bombay Hook National Wildlife Refuge protects a vast parcel of tidal salt marsh and an extensive network of tidal creeks. These areas are not only essential wildlife habitat, but are critical components for maintaining water quality in Delaware Bay and the Atlantic.The shells of expired Atlantic Horseshoe Crabs were formerly widespread and common among the naturally occurring flotsam along the high tide line on Delaware Bay. We found just this one during our visit to Bombay Hook. Man has certainly decimated populations of this ancient crustacean during recent decades.As the tide goes out, it’s a good time for a quick walk into the salt marsh on the boardwalk trail opposite Raymond Pool.Among the Saltmarsh Cordgrass along the trail and on the banks of the tidal creek there, a visitor will find thousands and thousands of Atlantic Marsh Fiddler Crabs (Minuca pugnax).Atlantic Marsh Fiddler Crabs and their extensive system of burrows help prevent the compaction of tidal soils and thus help maintain ideal conditions for the pure stands of Saltwater Cordgrass that trap sediments and sequester nutrients in coastal wetlands.A male Atlantic Marsh Fiddler Crab peers from its den.Herons and egrets including this Great Egret are quite fond of fiddler crabs. As the tide goes out, many will venture away from the freshwater pools into the salt marshes to find them.A Green Heron seen just before descending into the cordgrass to find fiddler crabs for dinner.A juvenile Clapper Rail (Rallus crepitans crepitans) emerges from the cover of the cordgrass along a tidal creek to search for a meal.Glossy Ibis leave their high-tide hiding place in Shearness Pool to head out into the tidal marshes for the afternoon.Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide in the marshes opposite Shearness Pool.An Osprey patrols the vast tidal areas opposite Shearness Pool.
No visit to Bombay Hook is complete without at least a quick loop through the upland habitats at the far end of the tour route.
Indigo Buntings nest in areas of successional growth and yes, that is a Spotted Lanternfly on the grape vine at the far right side of the image.Blue Grosbeaks (Passerina caerulea) are common nesting birds at Bombay Hook. This one was in shrubby growth along the dike at the north end of Shearness Pool.These two native vines are widespread at Bombay Hook and are an excellent source of food for birds. The orange flowers of the Trumpet Vine are a hummingbird favorite and the Poison Ivy provides berries for numerous species of wintering birds.The Pileated Woodpecker is one of the numerous birds that supplements its diet with Poison Ivy berries. The tree this individual is visiting is an American Sweetgum (Liquidambar styraciflua), a species native to the Atlantic Coastal Plain in Delaware. The seed balls are a favorite winter food of goldfinches and siskins.Finis Pool has no frontage on the tidal marsh but is still worth a visit. It lies along a spur road on the tour route and is located within a deciduous coastal plain forest. Check the waters there for basking turtles like this giant Northern Red-bellied Cooter (Pseudemys rubiventris) and much smaller Painted Turtle.The White-tailed Deity is common along the road to Finis Pool.Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.The National Wildlife Refuge System not only protects animal species, it sustains rare and unusual plants as well. This beauty is a Turk’s Cap Lily (Lilium superbum), a native wildflower of wet woods and swamps.Just as quail led us into the refuge this morning, this Wild Turkey did us the courtesy of leading us to the way out in the afternoon.
We hope you’ve been convinced to visit Bombay Hook National Wildlife Refuge sometime soon. And we hope too that you’ll help fund additional conservation acquisitions and improvements by visiting your local post office and buying a Federal Duck Stamp.
This linear grove of mature trees, many of them nearly one hundred years old, is a planting of native White Oaks (Quercus alba) and Swamp White Oaks (Quercus bicolor).
Imagine the benefit of trees like this along that section of stream you’re mowing or grazing right now. The Swamp White Oak in particular thrives in wet soils and is available now for just a couple of bucks per tree from several of the lower Susquehanna’s County Conservation District Tree Sales. These and other trees and shrubs planted along creeks and rivers to create a riparian buffer help reduce sediment and nutrient pollution. In addition, these vegetated borders protect against soil erosion, they provide shade to otherwise sun-scorched waters, and they provide essential wildlife habitat. What’s not to love?
Autumn leaf of a Swamp White Oak
The following native species make great companions for Swamp White Oaks in a lowland setting and are available at bargain prices from one or more of the County Conservation District Tree Sales now underway…
The Red Maple is an ideal tree for a stream buffer project. They do so well that you should limit them to 10% or less of the plants in your project so that they don’t overwhelm slower-growing species.The River Birch (Betula nigra) is a multi-trunked tree of lowlands. Large specimens with arching trunks help shade waterways and provide a source of falling insects for surface-feeding fish. Its peeling bark is a distinctive feature.The Common Winterberry with its showy red winter-time fruit is a slow-growing shrub of wet soils. Only female specimens of this deciduous holly produce berries, so you need to plant a bunch to make sure you have both genders for successful pollination.An American Robin feeding on Common Winterberry.Common Spicebush is a shrub of moist lowland soils. It is the host plant for the Spicebush Swallowtail butterfly and produces small red berries for birds and other wildlife. Plant it widely among taller trees to provide native vegetation in the understory of your forest.Common Spicebush foliage and berries in the shade beneath a canopy of tall trees.The Common Pawpaw a small shade-loving tree of the forest understory.Common Pawpaw is a colony-forming small tree which produces a fleshy fruit. It is the host plant for the caterpillars of the Zebra Swallowtail.The Buttonbush is a shrub of wet soils. It produces a round flower cluster, followed by this globular seed cluster.And don’t forget the Eastern Sycamore, the giant of the lowlands. At maturity, the white-and-tan-colored bark on massive specimens makes them a spectacular sight along stream courses and river shores. Birds ranging from owls, eagles, and herons to smaller species including the Yellow-throated Warbler rely upon them for nesting sites.Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore.
So don’t mow, do something positive and plant a buffer!
Act now to order your plants because deadlines are approaching fast. For links to the County Conservation District Tree Sales in the Lower Susquehanna River Watershed, see our February 18th post.
County Conservation District Tree Sales are underway throughout the Lower Susquehanna River Watershed. Now is the time to order for pickup in April. The prices are a bargain and the selection is fabulous. For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue). And don’t forget to order bundles of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local birds. They’re only $12.00 for a bundle of 10—can’t beat that deal!
Pickup on: Thursday, April 20, 2023 or Friday, April 21, 2023
Don’t mow it. Plant a meadow or pollinator garden instead.Both Cumberland and Perry Counties are offering a native warm-season grass and wildflower seed mix for planting your own meadow or pollinator garden. Perry County is also taking orders for a seed mix specifically formulated to grow plants for attracting hummingbirds and butterflies.
Pickup on: Thursday, April 20, 2023 or Friday, April 21, 2023
The Eastern Hemlock, Pennsylvania’s official state tree, is an excellent choice for addition to your landscape or reforestation project. It tolerates rocky soils and its cones are an prime source of food for birds ranging from chickadees to finches.
The handsome yet underused Northern Red Oak is a sturdy long-lived native tree that is ideal for street-side, lawn, and reforestation plantings. In spring, it can be a magnet for migrating Neotropical birds when its flowers attract a wide variety of tiny insects to its upper reaches. Unlike many other oaks, this species is a relatively fast grower.
In autumn, even after the bright red foliage is gone, the berries of mature Black Gum (Nyssa sylvatica) trees attract a wide variety of birds like this Pileated Woodpecker. The Lebanon County Conservation District is offering Black Gum, also known as Black Tupelo, during their 2023 tree sale. Why not order and plant a half dozen or more?
The Perry County Conservation District is not only offering plants during this year’s sale, you can also purchase bluebird nest boxes for just $12.00 each!For less than the cost of one year of mowing, this stream corridor in Conewago Township, Dauphin County was reforested by the owner with hundreds of native trees, the majority purchased through County Conservation District Tree Sale events spanning a period of several years. By replacing bare soil and mowed areas, the riparian buffer created by these plantings has significantly reduced the nutrient and sediment loads that were polluting the small stream therein known as Brill’s Run. With determination and not a lot of money, you can do it too.But don’t forget the Eastern White Pines!
From a lookout atop an Eastern Hemlock, a Northern Mockingbird maintains a vigil over a garden full of berry-producing plants. To assure their survival during cold weather, these bold birds will vigorously defend winter food supplies on hollies, viburnums, poison-ivy, bittersweet, and other fruit-producing trees, shrubs, and vines, often swooping in to startle and flush birds and other animals that approach its stores too closely.
By November, as insects become more difficult to come by, migrating Yellow-rumped Warblers are seldom found far from a supply of berries. This one was in the vicinity of the white fruits of Poison Ivy vines.
Many cultivars of ornamental maples for the home garden are derived from this native species, and it’s easy to see why. Despite the variation in the foliage of each, every tree in this view is a Red Maple (Acer rubrum).The Red Maple is the most common and widespread tree in all of eastern North America. It is easily recognized by its three-lobed leaves. Not only do the fall foliage colors vary among a population of trees, but some individual specimens have a well-stocked palette of their own. This collection came from a single Red Maple. Visit a forested area today and check them out!
Thoughts of October in the Lower Susquehanna River Watershed bring to mind scenes of brilliant fall foliage adorning wooded hillsides and stream courses, frosty mornings bringing an end to the growing season, and geese and other birds flying south for the winter.
The autumn migration of birds spans a period equaling nearly half the calendar year. Shorebirds and Neotropical perching birds begin moving through as early as late July, just as daylight hours begin decreasing during the weeks following their peak at summer solstice in late June. During the darkest days of the year, those surrounding winter solstice in late December, the last of the southbound migrants, including some hawks, eagles, waterfowl, and gulls, may still be on the move.
The Rough-legged Hawk (Buteo lagopus), a rodent-eating raptor of tundra, grassland, and marsh, is rare as a migrant and winter resident in the lower Susquehanna valley. It may arrive as late as January, if at all.
During October, there is a distinct change in the list of species an observer might find migrating through the lower Susquehanna valley. Reduced hours of daylight and plunges in temperatures—particularly frost and freeze events—impact the food sources available to birds. It is during October that we say goodbye to the Neotropical migrants and hello to those more hardy species that spend their winters in temperate climates like ours.
During several of the first days of October, two hundred Chimney Swifts remained in this roost until temperatures warmed from the low forties at daybreak to the upper fifties at mid-morning; then, at last, the flock ventured out in search of flying insects. When a population of birds loses its food supply or is unable to access it, that population must relocate or perish. Like other insectivorous birds, these swifts must move to warmer climes to be assured a sustained supply of the flying bugs they need to survive. Due to their specialized food source, they can be considered “specialist” feeders in comparison to species with more varied diets, the “generalists”. After returning to this chimney every evening for nearly two months, the swifts departed this roost on October 5 and did not return.A Northern Parula lingers as an October migrant along the Susquehanna. This and other specialist feeders that survive almost entirely on insects found in the forest canopy are largely south of the Susquehanna watershed by the second week of October.The Blackpoll Warbler is among the last of the insectivorous Neotropical warblers to pass through the riparian forests of the lower Susquehanna valley each fall. Through at least mid-October, it is regularly seen searching for crawling insects and larvae among the foliage and bark of Northern Hackberry (Celtis occidentalis) trees near Conewago Falls. Most other warblers, particularly those that feed largely upon flying insects, are, by then, already gone.The Blue-headed Vireo, another insectivore, is the last of the vireo species to pass through the valley. They linger only as long as there are leaves on the trees in which they feed.Brown Creepers begin arriving in early October. They are specialist feeders, well-adapted to finding insect larvae and other invertebrates among the ridges and peeling bark of trees like this hackberry, even through the winter months.Ruby-crowned Kinglets can be abundant migrants in October. They will often behave like cute little flycatchers, but quickly transition to picking insects and other invertebrates from foliage and bark as the weather turns frosty. Some may spend the winter here, particularly in the vicinity of stands of pines, which provide cover and some thermal protection during storms and bitter cold.Beginning in early October, Golden-crowned Kinglets can be seen searching the forest wood for tiny invertebrates. They are the most commonly encountered kinglet in winter.The Yellow-bellied Sapsucker, a woodpecker, is an October migrant that specializes in attracting small insects to tiny seeps of sap it creates by punching horizontal rows of shallow holes through the tree bark. Some remain for winter.The Yellow-rumped Warbler arrives in force during October. It is the most likely of the warblers to be found here in winter. Yellow-rumped Warblers are generalists, feeding upon insects during the warmer months, but able to survive on berries and other foods in late fall and winter. Wild foods like these Poison Ivy berries are crucial for the survival of this and many other generalists.American Robins are most familiar as hunters of earthworms on the suburban lawn, but they are generalist feeders that rely upon fruits like these Eastern Red Cedar (Juniperus virginiana) berries during their southbound migration in late October and early November each year. Robins remain for the winter in areas of the lower Susquehanna valley with ample berries for food and groves of mature pines for roosting.Like other brown woodland thrushes, the Hermit Thrush (Catharus guttatus) is commonly seen scratching through organic matter on the moist forest floor in search of invertebrates. Unlike the other species, it is a cold-hardy generalist feeder, often seen eating berries during the southbound October migration. Small numbers of Hermit Thrushes spend the winter in the lower Susquehanna valley, particularly in habitats with a mix of wild foods.Due to their feeding behavior, Cedar Waxwings can easily be mistaken for flycatchers during the nesting season, but by October they’ve transitioned to voracious consumers of small wild fruits. During the remainder of the year, flocks of waxwings wander widely in search of foods like this Fox Grape (Vitis labrusca). An abundance of cedar, holly, Poison Ivy, hackberry, bittersweet , hawthorn, wild grape, and other berries is essential to their survival during the colder months.Red-breasted Nuthatches have moved south in large numbers during the fall of 2020. They were particularly common in the lower Susquehanna region during mid-October. Red-breasted Nuthatches can feed on invertebrates during warm weather, but get forced south from Canada in droves when the cone crops on coniferous trees fail to provide an adequate supply of seeds for the colder fall and winter seasons. In the absence of wild foods, these generalists will visit feeding stations stocked with suet and other provisions.Purple Finches (Haemorhous purpureus) were unusually common as October migrants in 2020. They are often considered seed eaters during cold weather, but will readily consume small fruits like these berries on an invasive Mile-a-minute Weed (Persicaria perfoliata) vine. Purple Finches are quite fond of sunflower seeds at feeding stations, but often shy away if aggressive House Sparrows or House Finches are present.
The need for food and cover is critical for the survival of wildlife during the colder months. If you are a property steward, think about providing places for wildlife in the landscape. Mow less. Plant trees, particularly evergreens. Thickets are good—plant or protect fruit-bearing vines and shrubs, and allow herbaceous native plants to flower and produce seed. And if you’re putting out provisions for songbirds, keep the feeders clean. Remember, even small yards and gardens can provide a life-saving oasis for migrating and wintering birds. With a larger parcel of land, you can do even more.
GOT BERRIES? Common Winterbery (Ilex verticillata) is a native deciduous holly that looks its best in the winter, especially with snow on the ground. It’s slow-growing, and never needs pruning. Birds including bluebirds love the berries and you can plant it in wet ground, even along a stream, in a stormwater basin, or in a rain garden where your downspouts discharge. Because it’s a holly, you’ll need to plant a male and a female to get the berries. Full sun produces the best crop. Fall is a great time to plant, and many garden centers that sell holiday greenery still have winterberry shrubs for sale in November and December. Put a clump of these beauties in your landscape. Gorgeous!
They get a touch of it here, and a sparkle or two there. Maybe, for a couple of hours each day, the glorious life-giving glow of the sun finds an opening in the canopy to warm and nourish their leaves, then the rays of light creep away across the forest floor, and it’s shade for the remainder of the day.
The flowering plants which thrive in the understory of the Riparian Woodlands often escape much notice. They gather only a fraction of the daylight collected by species growing in full exposure to the sun. Yet, by season’s end, many produce showy flowers or nourishing fruits of great import to wildlife. While light may be sparingly rationed through the leaves of the tall trees overhead, moisture is nearly always assured in the damp soils of the riverside forest. For these plants, growth is slow, but continuous. And now, it’s show time.
So let’s take a late-summer stroll through the Riparian Woodlands of Conewago Falls, minus the face full of cobwebs, and have a look at some of the strikingly beautiful plants found living in the shadows.
Oxeye (Heliopsis helianthoides) is common on the interior and along the edges of Riparian Woodland. Specimens in deep shade flower less profusely and average less than half the height of the five feet tall inhabitants of edge environs.Pale Touch-Me-Not (Impatiens pallida) is one of two species of native Impatiens foundin the river floodplain. Both are known as Jewelweed. The stems and leaves of the indigenous Impatiens retain a great quantity of water, so life in filtered sunlight is essential to prevent desiccation. Contrary to popular folklore, extracts of Jewelweed plants are not effective treatments of Poison Ivy (Toxicodendron radicans) contact dermatitis.Spotted Touch-Me-Not (Impatiens capensis) is typically found in wetter soil than I. pallida. Both Jewelweeds develop popping capsules which help to distribute the seeds of these annual wildflowers. “Touch Me Not”, or you’ll be wearing tiny seeds.Green-headed Coneflower (Rudbeckia laciniata) grows to heights of eight feet in full sun, hence its alternate common name, Tall Coneflower. In deep shade, it may not exceed two feet in height. Floodplains are the prime domain of this perennial.Wingstem (Verbesina alternifolia) normally flowers no earlier than late August. The bases of the leaves are continued onto the stem of the plant to form wings which extend downward along its length. This wildflower tolerates shade, but flowers more profusely along the woodland edge.Great Lobelia (Lobelia siphilitica), or Great Blue Lobelia, is a magnificent wetland and moist woodland wildflower, usually attaining three feet in height and adorned with a plant-topping spike of blossoms. Invasive Japanese Stiltgrass (Microstegium vimineum) can be seen here competing with this plant, resulting in a shorter, less productive Lobelia. Stiltgrass was not found in the Susquehanna River floodplain at Conewago Falls until sometime after 1997. It has spread to all areas of woodland shade, its tiny seeds being blown and translocated along roads, mowed lots, trails, and streams to quickly colonize and overtake new ground.American Bladdernut (Staphylea trifolia), a shrub of shaded woods, develops inflated capsules which easily float away during high water to distribute the seeds contained inside.Buttonbush (Cephalanthus occidentalis) is a shrub of wet soils which produces a strange spherical flower, followed by this globular seed cluster.Common Pawpaw (Asimina triloba) is a colony-forming small tree which produces a fleshy fruit. It is the host plant for the caterpillars of the Zebra Swallowtail. The plant and the butterfly approach the northern limit of their geographic range at Conewago Falls.Common Spicebush (Lindera benzoin) is a widespread understory shrub in wet floodplain soils. It is the host plant for the caterpillars of the Spicebush Swallowtail (Papilio troilus).Sweet Autumn Virgin’s Bower (Clematis terniflora) is an escape from cultivation which has recently naturalized in the edge areas of the Conewago Falls Riparian Woodlands. This vine is very showy when flowering and producing seed, but can be detrimental to some of the understory shrubs upon which it tends to climb.
SOURCES
Long, David; Ballentine, Noel H.; and Marks, James G., Jr. 1997. Treatment of Poison Ivy/Oak Allergic Contact Dermatitis With an Extract of Jewelweed. American Journal of Contact Dermatitis. 8(3): pp. 150-153.
Newcomb, Lawrence. 1977. Newcomb’s Wildflower Guide. Little, Brown and Company. Boston, Massachusetts.
