Since Tuesday’s snow storm, the susquehannawiildlife.net headquarters garden continues to bustle with bird activity.
Our Northern Mockingbird remains ever vigilant in its attempts to discourage American Robins and Eastern Bluebirds from feeding on the berry crop. Slowly, the latter species are winning the contest.A Carolina Chickadee carefully dissects a sunflower seed to snack on the nutritious kernel.This beauty shows us that yes, Red-bellied Woodpeckers do indeed have red bellies.Getting energized for a big move north, the robins keep on gulping berries.
Today, there arrived three species of birds we haven’t seen here since autumn. These birds are, at the very least, beginning to wander in search of food. Then too, these may be individuals creeping slowly north to secure an advantage over later migrants by being the first to establish territories on the most favorable nesting grounds.
This Song Sparrow is the first we’ve seen in the garden since sometime last fall. Is it working its way north or did it just come to town in search of food?Northern Flickers regularly spend the winter in small numbers in the Lower Susquehanna River Watershed. This is the first one we’ve had visit the garden since late last autumn.Fish Crows, seen here feeding on the fruits adorning an Eastern Red Cedar, have returned after being absent in our neighborhood since November. In coming weeks, both they and the more numerous American Crows that remained through winter will begin constructing nests in nearby trees.
They say the early bird gets the worm. More importantly, it gets the most favorable nesting spot. What does the early birder get? He or she gets out of the house and enjoys the action as winter dissolves into the miracle of spring. Do make time to go afield and marvel a bit, won’t you? See you there!
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.
With the earth at perihelion (its closest approach to the sun) and with our home star just 27 degrees above the horizon at midday, bright low-angle light offered the perfect opportunity for doing some wildlife photography today. We visited a couple of grasslands managed by the Pennsylvania Game Commission to see what we could find…
On this State Game Lands parcel, prescribed fire is used to maintain a mix of grasslands and brushy early successional growth. In nearby areas, both controlled fire and mechanical cutting are used to remove invasive species from hedgerows and the understory of woodlots. Fire tolerant native species then have an opportunity to recolonize the forest and improve wildlife habitat. This management method also reduces the fuel load in areas with the potential for uncontrolled wildfires.The sun-dried fruits of a native Common Persimmon tree found growing in a hedgerow.Just one year ago, mechanical removal of invasive trees and shrubs (including Multiflora Rose) on this State Game Land was followed by a prescribed fire to create this savanna-like grassland.Hundreds of Song Sparrows were found in the grasses and thickets at both locations.White-throated Sparrows were also abundant, but prefer the tangles and shrubs of the thickets.Northern Mockingbirds were vigilantly guarding winter supplies of berries in the woodlots and hedgerows.In grasses and tangles on wetter ground, about a dozen Swamp Sparrows were discovered.The adult White-crowned Sparrow is always a welcome find.And seeing plenty of juvenile White-crowned Sparrows provides some assurance that there will be a steady stream of handsome adult birds arriving to spend the winter during the years to come.Dark-eyed Juncos were encountered only in the vicinity of trees and large shrubs.Several Savannah Sparrows were observed. Though they’re mostly found in treeless country, this particular one happened to pose atop a clump of shrubs located within, you guessed it, the new savanna-like grasslands.A tiny bird, even when compared to a sparrow, the Winter Wren often provides the observer with just a brief glimpse before darting away into the cover of a thicket.Within grasslands, scattered stands of live and dead timber can provide valuable habitat for many species of animals.Woodpeckers and other cavity-nesting birds rely upon an abundance of “snags” (standing dead trees) for breeding sites.This Red-bellied Woodpecker and about a dozen others were found in trees left standing in the project areas.A Yellow-bellied Sapsucker soaks up some sun.This very cooperative Pileated Woodpecker seemed to be preoccupied by insect activity on the sun-drenched bark of the trees. This denizen of mature forests will oft times wander into open country where larger lumber is left intact.
Just as things were really getting fun, some late afternoon clouds arrived to dim the already fading daylight. Just then, this Northern Harrier made a couple of low passes in search of mice and voles hidden in the grasses.It was a fitting end to a very short, but marvelously sunny, early winter day.
As the annual autumn songbird migration begins to reach its end, native sparrows can be found concentrating in fallow fields, early successional thickets, and brushy margins along forest edges throughout the Lower Susquehanna River Watershed.
A streamside thicket composed of seed-producing grasses and wildflowers as well as fruit-bearing shrubs and vines can be ideal habitat for migrating and wintering native sparrows.
Visit native sparrow habitat during mid-to-late November and you have a good chance of seeing these species and more…
The Song Sparrow can be found in woody brush and grassy margins from the shores of the Susquehanna all the way up to the ridgetops of the Appalachians.During the colder months of the year, the Dark-eyed Junco is a familiar visitor to bird-feeding stations. Where suitable natural cover is present, they regularly venture into suburban and urban settings.The White-throated Sparrow is commonly found in the company of juncos, but is generally less adventurous, being more likely in weedy fields near young woodlands than in suburban gardens.The Eastern Towhee is a large native sparrow most often found in early successional growth near woodlands. Look for them in utility right-of-ways.The elusive Fox Sparrow is a regular late-fall migrant. Few stay for the winter, but northbound birds can be seen as early as mid-February each year.
If you’re lucky enough to live where non-native House Sparrows won’t overrun your bird feeders, you can offer white millet as a supplement to the wild foods these beautiful sparrows might find in your garden sanctuary. Give it a try!
It’s just common sense to take it easy and drive carefully when snow covers streets and highways. Everyone knows that. But did you know that slowing down when the landscape is blanketed in white can save lives even after the roadways have been cleared?
Following significant snowfalls such as the one earlier this week, birds and other wildlife are attracted to bare ground along the edges of plowed pavement. They are often so preoccupied with the search for food that they ignore approaching cars and trucks until it is too late.
Take a look at the species found today along a one mile stretch of plowed rural roadway in the lower Susquehanna valley.
Following snow storms, birds that normally feed among leaf litter on the forest floor or in thickets and fields are attracted to plowed roads. During their urgent search for food, many are struck and killed by motor vehicles.White-throated Sparrows commonly congregate along roads passing through woodlands and thickets.A juvenile White-crowned Sparrow looks for food among leaves along the edge of snow-free pavement.Adult White-crowned Sparrows take cover in roadside shrubs until traffic passes. Within moments they’ll return to a patch of bare ground along the road’s narrow shoulder.Dark-eyed Juncos are commonly encountered along roads through snow-covered weedy fields and suburbia.Song Sparrows gather along roads traversing brushy areas.Juvenile White-crowned Sparrows and, to the upper right, an American Tree Sparrow (Spizella arborea) take refuge in a small roadside sapling after fleeing a passing automobile.This Yellow-rumped Warbler was attracted to berry-laden shrubs and vines in a road cut with a southern exposure and patches of bare ground.Following a snowfall, Eastern Bluebirds are regularly seen feeding along the edges of rural roads.Horned Larks gather along the snow-free margins of roads through tundra-like farmland.
For many species of wildlife in the Lower Susquehanna River Watershed, the fragmented and impaired state of habitat already challenges their chances of surviving the winter. Snow cover can isolate them from their limited food supplies and force them to roadsides and other dangerous locations to forage. Mauling them with motor vehicles just adds to the escalating tragedy, so do wildlife and yourself a favor—please slow down.
Even in areas with ideal habitat, snow cover will cause birds and other wildlife to explore bare ground along highways while seeking food.Ring-necked Pheasants frequently become traffic casualties. These birds feeding at roadside due to the snow cover are in increased peril.
Temperatures plummeted to well below freezing during the past two nights, but there was little sign of it in Conewago Falls this morning. The fast current in the rapids and swirling waters in flooded Pothole Rocks did not freeze. Ice coated the standing water in potholes only in those rocks lacking a favorable orientation to the sun for collecting solar heat during the day to conduct into the water during the cold nights.
On the shoreline, the cold snap has left its mark. Ice covers the still waters of the wetlands. Frost on exposed vegetation lasted until nearly noontime in shady areas. Insect activity is now grounded and out of sight. The leaves of the trees tumble and fall to cover the evidence of a lively summer.
The nocturnal bird flight is narrowing down to just a few species. White-throated Sparrows, a Swamp Sparrow (Melospiza georgiana), and Song Sparrows are still on the move. Though their numbers are not included in the migration count, hundreds of the latter are along the shoreline and in edge habitat around the falls right now. Song Sparrows are present year-round, migrate at night, and are not seen far from cover in daylight, so migratory movements are difficult to detect. It is certain that many, if not all of the Song Sparrows here today have migrated and arrived here recently. The breeding population from spring and summer has probably moved further south. And many of the birds here now may remain for the winter. Defining the moment of this dynamic, yet discrete, population change and logging it in a count would certainly require different methods.
Song Sparrows are now abundant in the brushy edges of fields and woodlands. They may even break into song on sunny days.
Diurnal migration was foiled today by winds from southerly directions and moderating temperatures. The only highlight was an American Robin flight that extended into the morning for a couple of hours after daybreak and totaled over 800 birds. This flight was peppered with an occasional flock of blackbirds. Then too, there were the villains.
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They’re dastardly, devious, selfish, opportunistic, and abundant. Today, they were the most numerous diurnal migrant. Their numbers made this one of the biggest migration days of the season, but they are not recorded on the count sheet. It’s no landmark day. They excite no one. For the most part, they are not recognized as migrants because of their nearly complete occupation of North America south of the taiga. If people build on it or alter it, these birds will be there. They’re everywhere people are. If the rotten attributes of man were wrapped up into one bird, an “anthropoavian”, this would be it.
Meet the European Starling (Sturnus vulgaris). Introduced into North America in 1890, the species has spread across the entire continent. It nests in cavities in buildings and in trees. Starlings are aggressive, particularly when nesting, and have had detrimental impacts on the populations of native cavity nesting birds, particularly Red-headed Woodpeckers, Purple Martins (Progne subis), and Eastern Bluebirds. They commonly terrorize these and other native species to evict them from their nest sites. European Starlings are one of the earlier of the scores of introduced plants and animals we have come to call invasive species.
Noisy flocks of European Starlings are right at home on man-made structures in city and country.
Today, thousands of European Starlings were on the move, working their way down the river shoreline and raiding berries from the vines and trees of the Riparian Woodlands. My estimate is between three and five thousand migrated through during the morning. But don’t worry, thousands more will be around for the winter.
European Starlings mob a Sharp-shinned Hawk from above, a common behavior.An Eastern Bluebird feeds on the few berries left untouched by passing European Starlings.
There’s something frightening going on down there. In the sand, beneath the plants on the shoreline, there’s a pile of soil next to a hole it’s been digging. Now, it’s dragging something toward the tunnel it made. What does it have? Is that alive?
We know how the system works, the food chain that is. The small stuff is eaten by the progressively bigger things, and there are fewer of the latter than there are of the former, thus the whole network keeps operating long-term. Some things chew plants, others devour animals whole or in part, and then there are those, like us, that do both. In the natural ecosystem, predators keep the numerous little critters from getting out of control and decimating certain other plant or animal populations and wrecking the whole business. When man brings an invasive and potentially destructive species to a new area, occasionally we’re fortunate enough to have a native species adapt and begin to keep the invader under control by eating it. It maintains the balance. It’s easy enough to understand.
Japanese Beetles (Popillia japonica) seen here on Halberd-leaved Rose Mallow. Without predation, exploding numbers of this invasive non-indigenous insect can defoliate and kill numerous species of plants in a given area.The Song Sparrow (Melospiza melodia) is a generalist feeder, eating seeds and invertebrates including Japanese Beetles. This species is the omnipresent year-round occupant of shoreline vegetation along the lower Susquehanna River.
Late summer days are marked by a change in the sounds coming from the forests surrounding the falls. For birds, breeding season is ending, so the males cease their chorus of songs and insects take over the musical duties. The buzzing calls of male “Annual Cicadas” (Neotibicen species) are the most familiar. The female “Annual Cicada” lays her eggs in the twigs of trees. After hatching, the nymphs drop to the ground and burrow into the soil to live and feed along tree roots for the next two to five years. A dry exoskeleton clinging to a tree trunk is evidence that a nymph has emerged from its subterranean haunts and flown away as an adult to breed and soon thereafter die. Flights of adult “Annual Cicadas” occur every year, but never come anywhere close to reaching the enormous numbers of “Periodical Cicadas” (Magicicada species). The three species of “Periodical Cicadas” synchronize their life cycles throughout their combined regional populations to create broods that emerge as spectacular flights once every 13 or 17 years.
An “Annual Cicada” also known as a “Dog-day Cicada”, clings to the stem of a Halberd-leaved Rose Mallow at Conewago Falls.
For the adult cicada, there is danger, and that danger resembles an enormous bee. It’s an Eastern Cicada Killer (Specius speciosus) wasp, and it will latch onto a cicada and begin stinging while both are in flight. The stings soon paralyze the screeching, panicked cicada. The Cicada Killer then begins the task of airlifting and/or dragging its victim to the lair it has prepared. The cicada is placed in one of more than a dozen cells in the tunnel complex where it will serve as food for the wasp’s larvae. The wasp lays an egg on the cicada, then leaves and pushes the hole closed. The egg hatches in a several days and the larval grub is on its own to feast upon the hapless cicada.
An Eastern Cicada Killer (Sphecius speciosus) along the river shoreline. Despite their intimidating appearance, they do not sting humans and can be quite docile when approached.
Other species in the Solitary Wasp family (Sphecidae) have similar life cycles using specific prey which they incapacitate to serve as sustenance for their larvae.
A Solitary Wasp, one of the Thread-waisted Wasps (Ammophila species), drags a paralyzed moth caterpillar to its breeding dungeon in the sandy soil at Conewago Falls. For the victim, there is no escape from the crypt.
The Solitary Wasps are an important control on the populations of their respective prey. Additionally, the wasp’s bizarre life cycle ensures a greater survival rate for its own offspring by providing sufficient food for each of its progeny before the egg beginning its life is ever put in place. It’s complete family planning.
The cicadas reproduce quickly and, as a species, seem to endure the assault by Cicada Killers, birds, and other predators. The Periodical Cicadas (Magicicada), with adult flights occurring as a massive swarm of an entire population every thirteen or seventeen years, survive as species by providing predators with so ample a supply of food that most of the adults go unmolested to complete reproduction. Stay tuned, 2021 is due to be the next Periodical Cicada year in the vicinity of Conewago Falls.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York.
