Mice and Voles (Cricetidae) – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

April 14, 2026April 15, 2026

Managing a Grassland Ecosystem

If you’ve visited Middle Creek Wildlife Management Area anytime during the past month, you may have noticed quite a bit of activity around the large pole-mounted nest boxes placed out in the open fields.

American Kestrels at nest box — American Kestrels, a male and female, at a nest box at Middle Creek Wildlife Management Area.

Kestrels competing for nesting sites and territory. — Within the past week, we noticed that kestrels are still competing for nesting sites and territory, driving away unwanted trespassers. A pair of kestrels seemed to be occupying each of the four box sites we observed. That’s good news, but the presence of these man-made nest cavities is in no way wholly responsible for this positive response from these declining birds. It’s a matter of habitat, much needed grassland habitat.

Cool Season Grasses — Cool-season grasses including fescue (Lolium species) and Orchard Grass (Dactylis glomerata) mature by late spring. If left standing, they continue to provide indispensable habitat for grassland wildlife through the summer. Mowing early and often for hay harvest has rendered most cool-season meadows death traps for nesting birds. By delaying cuttings until at least early August, ground-nesting birds are given adequate time to fledge their young and get the juvenile birds strong enough to fly away from a set of spinning blades.

Grasshopper Sparrow in Timothy — A male Grasshopper Sparrow sings to demarcate its nesting territory in a stand of Timothy. An insectivore during the breeding season, he and his mate will raise their brood exclusively within the cover of these cool-season grasses.

Eastern Meadowlarks arrive in cool-season grasslands by late-winter to begin their breeding cycle which typically extends into the hot summer days of July.

Orchard Grass with Black-eyed Susans — Prior to being mowed, Orchard Grass provides the short, dense cover meadowlarks and other ground-nesting grassland birds need to successfully reproduce. Growing a cool season grassland can be as easy as delaying the mowing of a pasture, field, or oversize lawn until August, then have a farmer friend come and take off a cutting or two of hay or straw to prevent woody plants from becoming established.

Warm-season Grasses — More durable stands of native warm-season grasses including Big Bluestem, Indiangrass, Switchgrass, and Little Bluestem thrive in the summer heat and provide wildlife habitat throughout the year. These perennial “prairie grasses”, fed by root systems five to eight feet deep, are especially drought tolerant . From these entrenched anchors, the plants would quickly bounce back after the once great herds of hungry bison had grazed the landscape bare of surface vegetation before moving on. This adaptation also assured “prairie grass” regeneration following naturally occurring seasonal fires, events mimicked in eastern North America by its earliest human residents. They used recurrent fire to perpetuate early successional habitat for wildlife propagation, foraging, and agriculture. Today in the lower Susquehanna watershed, establishing warm-season grassland meadows requires soil prep and seeding to get things going again.

Precribed Burn — To prevent succession, warm-season grassland parcels are most commonly maintained using applications of prescribed fire every 3 to 5 years. Among their benefits, these burns invigorate native vegetation while inhibiting the invasive tendencies of many non-native plants. Well-planned periodic fire can significantly reduce fuel accumulations, particularly in tinderbox woodland tracts managed as fire-free zones for the past century or more. Many forest trees including oaks rely on sporadic fire events for regeneration.

LEARN HOW LAND MANAGERS UTILIZE PRESCRIBED FIRE

This coming Saturday, April 18, 2026, beginning at 10 A.M. (rain date April 25), the Pennsylvania Game Commission is hosting a “Prescribed Fire Festival” at Middle Creek Wildlife Management Area. Be certain to come out to the visitor’s center at 100 Museum Road, Stevens, PA, for this event. Land managers will be there to answer questions and to explain the planning and preparations involved in overseeing a prescribed burn. There will be guided walks of habitats preserved using fire of varying intensities. You’ll see the equipment and protective clothing used by certified personnel to administer a live prescribed fire burn right before your eyes. Then you can have lunch—food trucks will be available on site.

Prescribed Fire Demonstration — Visitors witness a prescribed fire demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area in 2025.

After the burn demonstration, why not go for a walk or drive around the refuge. You can take note of how grassland and early successional plant communities are responding to previous doses of prescribed fire…

Greening up a week or two after the burn, Wingstem is blooming by June in areas treated using prescribed fire earlier in the spring.

Another scene from June: Four-foot-tall Joe-Pye-Weed amidst lush growth of goldenrod in early successional habitat where a prescribed burn eliminated accumulating wildfire fuel and turned back the growth of invasive plant species in March.

And how the grassland animals respond as well…

Ring-necked Pheasants in early successional habitat maintained by the periodic application of prescribed fire.

Eastern Cottontails prosper in the mosaic of warm-season grasses and early successional thickets on lands sustained using prescribed fire. Rabbits are herbivores, primary consumers eating mostly legumes and other plants, the producers that through the process of photosynthesis convert the energy of the the sun into food energy.

Other small vegetation-eating rodents including mice and voles thrive in managed grasslands. Similar in appearance are the shrews. Though seldom noticed, Northern Short-tailed Shrews spend day and night foraging for food, even in the shallow waters of wet meadows and thickets. Unlike the aforementioned herbivorous rodents, shrews are insectivores, secondary consumers feeding mostly on primary consumers including a variety of insects and other arthropods.

Some years ago, we found this tiny Masked Shrew (Sorex cinereus) in a grassland area being preserved using prescribed fire. Like other shrews, Masked Shrews are secretive, but always on the go. They feed constantly to fuel their vast energy requirements, sometimes consuming three times their body weight in a single day. But their voracious appetite can get them into trouble, causing these incessant eaters to encounter numerous potentially infective parasites during their non-stop foraging missions.

Female American Kestrel — Patrolling the grasslands is the female American Kestrel, a secondary consumer. She’s on the lookout for primary consumers including large insects like grasshoppers or crickets. But perhaps more likely is a small rodent whose less-than-ideal vigor may cause it to slip up, creating an easy target. If she selects a careless shrew as her prey, she may be assuming the role of a tertiary consumer, eating a secondary consumer (the shrew) that fed on insects (the primary consumers) that derived their energy from photosynthesized plant matter.

The strictly nocturnal American Barn Owl (Tyto furcata), another secondary and sometimes tertiary consumer, takes the night shift, hunting unwary voles, mice, and shrews, often by sensing the sounds they make among runways in the grass. As a native predator in its favored habitat, the owl’s selection of each victim actually helps to keep the prey species’ population healthy, eliminating the weak and vulnerable to provide a qualitative service to the surviving wildlife of the grasslands. While we may not think of the barn owl as a direct consumer of insects, its positive influence on insectivorous shrew populations makes it an important functionary in maintaining balance in the ecosystems it calls home.

Male American Kestrel — As food becomes increasing plentiful in the grasslands, a female kestrel will remain mostly out of sight, performing the majority of the egg incubation duties while her colorful mate stands guard nearby.

The fate of an avian predator such as a kestrel lies at the mercy of the fate of its quarry. Because, you see, the sun’s energy, after being converted to chemical energy by photosynthesizing plants, flows upward through the trophic levels of the food chain—herbivores (primary consumers) such as rodents and insects to carnivores (secondary and tertiary consumers) including kestrels. Grasslands, when abundant and diverse, are correspondingly abundant and diverse with small mammals and insects and will therefore support thriving populations of American Kestrels and other predators. These secondary and sometimes tertiary consumers fulfill a role in cultivating healthier populations of their prey, the primary and secondary consumers in the food web, as a balanced component of a flourishing grassland ecosystem. Sparse and fragmented grasslands, on the other hand, beget negligible small mammal and insect populations, are stricken with broken food webs, and champion few if any American Kestrels or other predators. If the land it occupies is neat, tidy, manicured, exploited, or sprayed sterile and dead, the energy flow cycle of the ecosystem is dead as well. There’s nothing animal introductions, reintroductions, rescues, culling, stocking, or harvesting can do about it, because in the end, it’s all about the habitat.

February 14, 2026February 16, 2026

Adapting to Winter Extremes

During winter’s harshest conditions, one must frequently marvel at the methods various forms of wildlife have to survive. Take a look at some of the animals we found using their life-sustaining adaptations to find food amidst the snow-covered landscape and bitter cold air.

We watched this Blue Jay digging to retrieve an acorn from beneath the tuft of leaves and dried grasses where it had apparently concealed it earlier in the season.

Blue Jay Eating Acorn — It then carried it to a nearby limb and chiseled away the husk to devour the nutritious contents. Blue Jays are known to cache hundreds or even thousands of seeds, nuts, and acorns for winter consumption. Want to see it for yourself? Just put out some unshelled no-salt peanuts and watch the jays haul them away, that is if the hoarding squirrels don’t get them first!

Like other members of the Picidae family, Red-headed Woodpeckers pry and chisel away at decaying and insect-infested trees to find food during the winter.

First-winter Red-headed Woodpecker — Like jays, Red-headed Woodpeckers including this first-winter bird are very fond of acorns and will often collect them from the ground. And like jays, they’ll cache acorns for use as a backup supply when a blanket of snow may prevent them from gathering those that remain beneath the oaks.

Native to eastern Asia, Wintercreeper (Euonymus fortunei) has escaped from mostly urban cultivation to become naturalized and often invasive in some wooded areas of the lower Susquehanna River watershed. It can be quite aggressive, usually found growing as a climbing vine or less frequently as a shrub. In the absence of native and more palatable foods, the berries are an attractive survival fare for members of the Turidae (thrush) family and other birds.

We found this and several hundred more American Robins surviving the current winter weather while feeding on Wintercreeper in a suburban woods with a heavy growth of the invasive plant.

Several Eastern Bluebirds were seen among the Wintercreeper tangles as well. They too are relying upon this non-native plant to provide at least a portion of the energy they need to make through blustery February nights.

The Hermit Thrush, a species that nests in the coniferous and mixed forests of the northern United States and Canada, winters sparingly in the lower Susquehanna valley. We found this one among the robins and bluebirds of the Wintercreeper thicket where it too was probably attracted by the supply of berries.

Frequently escaping notice in the winter woods is the Brown Creeper, another species that nests primarily in coniferous and mixed forests to our north, though it does breed in our area at scattered locations, primarily in mountainous or swampy terrain.

The petite Winter Wren exhibits mouse-like behavior as it hops and crawls among logs, rocks, and brush along the banks of wooded waterways. Like the creeper, it is primarily an insectivore, spending much of its time escaping notice searching beneath streamside structure for its daily nourishment. In summer, Winter Wrens nest in damp coniferous forests.

Seeing a Red Fox repeatedly during daylight hours is typically considered to be a sign that one may be observing a diseased animal, but we soon determined that there was nothing at all wrong with this vulpid we found patrolling a large woodland lying along the outskirts of a lower Susquehanna city.

May 13, 2025May 13, 2025

Nest Builders at Work

For many animals, an adequate shelter is paramount for their successful reproduction. Here’s a sample of some of the lower Susquehanna valley’s nest builders in action…

Pileated Woodpecker Excavating Nest — Many of our year-round resident bird species get a head start on the breeding season as cavity nesters. Some of these mated pairs use naturally occurring hollows, while still others take advantage of the voids left vacant by the more industrious previous occupants. Woodpeckers in particular are responsible for excavating many of the cavities that are later used as homes by a variety of birds and mammals to both rear their young and provide winter shelter. Pileated Woodpeckers, like other members of the family Picidae, have an almost mystic ability to locate diseased or insect-infested trees for selection as feeding and nesting sites. In this composite image, a pair is seen already working on a potential nursery during mid-January. After use by the woodpeckers, abandoned cavities of this size can become nesting sites for a variety of animals including bees, small owls, Great Crested Flycatchers, Wood Ducks, Hooded Mergansers, and squirrels.

Downy Woodpecker at Nest — After use as a nesting site, a void excavated by Downy Woodpeckers can be occupied in subsequent years by chickadees, titmice, nuthatches, wrens, and other cavity-dwelling species.

Muskrat with Leafy Twig — This Muskrat (*Ondatra zibethicus)* with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,…

Muskrat House — A Muskrat house in March. In the absence of leafy twigs, dried cattail stems will suffice. As it ages and decays, the house’s organic matter generates heat and makes an ideal location for turtles to deposit and hatch their eggs.

Soon after Neotropical migrants begin arriving in the forests of the lower Susquehanna watershed, they begin constructing their nests. The majority of these species build “outdoors”, not within the confines of a tree cavity. Here we see a Wood Thrush with its bill full of dried leaves and other materials…

Wood Thrush Nest — …ready to line the cup of its nest in the fork of a small understory tree.

Though it often arrives during early April after spending the winter in sub-tropical and even some temperate climes, the Blue-gray Gnatcatcher must wait to start construction of its nest until many of the Neotropical migrants arrive in early May.

Blue-gray Gnatcatchers — Back at the nest site…

Baltimore Oriole with Nesting Material — Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.

Baltimore Oriole Nest — Unfortunately for them, man-made litter can often seem to be the ideal material for binding the nest together. In an area only sporadically visited by anglers, this oriole had no trouble finding lots of monofilament fishing line, trash that can fatally entangle both adult and young birds of any species. If you see any fishing line at all, please pick it up and dispose of it properly.

Baltimore Oriole — Always keep an eye open for fishing line and get it before the birds do!

Like many other avians, male Brown-headed Cowbirds are now relentlessly pursuing females of their kind.

Watching and waiting. The Indigo Bunting evades cowbird parasitism by first recognizing the invader’s egg. They then either add a new layer of nest lining over it or they abandon the nest completely and construct a new one. Some patient buntings may delay their breeding cycle until after cowbird courting behavior ceases in coming weeks.

March 24, 2025March 24, 2025

Wildlife in the Burn Zone

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

Back Fire Ignition during prescribed burn demonstration. — Pennsylvania Game Commission crews ignite a back fire to contain a prescribed burn along its downwind/upslope perimeter during a demonstration at Middle Creek Wildlife Management Area on Saturday.

Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.

Red-tailed Hawks and other raptors, including nocturnal owls, are frequently the first visitors attracted to the scene of a prescribed burn or wildfire. In grassland and successional habitats, they come looking for any vulnerable voles or mice that may be moving about looking for cover.

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

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

White-crowned and White-throated Sparrows — Apparently feeding upon slightly heat-treated seeds, sparrows were found by the dozens. White-crowned (left), White-throated (right), Song, and Savannah Sparrows were identified.

This Downy Woodpecker was finding something to its liking among the scorched leaves, stems, and twigs.

American Robins seem to find areas with lightly burnt vegetation and ash-dusted soil advantageous for finding invertebrates following a fire.

Mixed Flock of Blackbirds — We found this flock of Red-winged Blackbirds, Browned-headed Cowbirds, and a few European Starlings feeding throughout a grassland field cleared of early-successional growth by a prescribed fire administered one week ago.

American Kestrel at Nest Box — A male American Kestrel at a nest box located among Middle Creek’s warm-season and cool-season grassland habitats, the former maintained by prescribed fire, the latter by delayed mowing.

February 26, 2025August 4, 2025

Winter Survival: Generalists and Specialists

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

House Sparrows and a House Finch — House Sparrows (bottom) and House Finches (top) are generalists. To survive and thrive, they are adapted to a variety of habitats and types of food. House Sparrows live almost anywhere man-made structures are found. They are true omnivores and will eat almost anything, especially if they see something else try to eat it first. The House Sparrow’s close association with humans has allowed it to become the most widespread and successful living avian dinosaur. On a cold night, they’ll take shelter either within dense vegetation alongside a building or within the structure itself. Though not nearly as cosmopolitan, the House Finch has successfully colonized much of the eastern United States after escaping from captivity as a cage bird in New York during the middle of the twentieth century. Upon being trans-located here from the arid southwest, they adapted to suburbs and farmlands consuming primarily a granivore diet of seeds supplemented with seasonally available berries. They quickly became accustomed to offerings at bird-feeding stations as well. To survive the harsh winters in the northern sections of their range, eastern populations of House Finches are developing a pattern of migration. These movements are most evident in late fall when dozens or sometimes hundreds can be seen heading south over regional hawk-counting stations.

Northern Flicker feeding on Poison Ivy — Though they require dead trees for nesting and as places to find the grubs and adult insects upon which they primarily feed, woodpeckers including the Northern Flicker are generalists, seldom passing by a supply of fruits like these Poison Ivy berries as a source of winter food. Flickers regularly visit suburban areas where they’ll drop by at bird-feeding stations for suet. During the warmer months, they are the woodpecker most frequently seen on the ground where swarms of ants garner their full attention.

The Pileated Woodpecker is seldom found outside of mature forests where it digs relentlessly to remove grubs and other infestations from dead wood. But it is not a true specialist…

Pileated Woodpecker eating Poison Ivy — …it too finds a supply of Poison Ivy berries to be indispensable during a cold winter day.

The Ruby-crowned Kinglet is a generalist, feeding mostly on insects, but also consuming small seeds and some berries, including those of Poison Ivy. It nests well to our north in tall spruces and other evergreens. During migration and in winter, the Ruby-crowned Kinglet may be found in deciduous trees, brush, and tall grass in habitats ranging from forests to parks and suburbia. This male is displaying its seldom-seen red crown.

The Golden-crowned Kinglet, seen here on a Poison Ivy vine, is more of a specialist than the Ruby-crowned species, though the two will often occur in mixed groups during the winter. The Golden-crowned Kinglet nests in Spruce-Fir forests and in conifers within mixed woodlands. Even during migration, and particularly in winter, these birds are seldom found far from a stand of large evergreens within which they find shelter for the night.

It’s insects for the nestlings during spring and summer, then berries through the winter for the cheerful Eastern Bluebirds, another generalist species.

American Crows are an excellent example of a generalist species. They’ll go anywhere to find food and they’ll eat almost anything. Like the House Sparrow and several other generalists, they adapt very well to human activity and actually thrive on it. Garbage anyone?

Another career generalist is the widely worshiped White-tailed Deity, a species adapted to nearly all man-made landscapes with adequate vegetation upon which to browse. Pushed to the limit during severe weather, some individuals will consume carrion and even resort to cannibalism.

You might think the Great Blue Heron is a specialist. Nope, it’s an accomplished generalist. Great blues will live, feed, and breed on almost any body of fresh or brackish water. And their diet includes almost anything that swims. In winter, you’ll even see them in fields hunting mice and voles.

The Red-shouldered Hawk is a generalist with a diet ranging from amphibians and reptiles to small rodents and large insects. Mostly regarded as a species of bottomlands, they’ll frequent woodland edges, roadsides, and suburbia during the winter months.

During its periodic winter visits to the region, the American Tree Sparrow feeds on seeds among the grasses and forbs of semi-open country with scattered short shrubs and trees. A generalist species, it will show up at backyard bird-feeding stations, particularly during periods of inclement weather. In summer, the American Tree Sparrow nests in tundra with growths of stunted willows and spruce and their diet includes insects as a source of protein for themselves and their young.

The White-crowned Sparrow has similar winter habitat preferences to the tree sparrows…

White-crowned Sparrows — …it becomes adaptable and something of a generalist when searching for food during bad winter storms.

The Savannah Sparrow is an omnivore favoring insects in summer and seeds in winter. Though very closely tied to its grassland habitat year-round, snow cover can push these birds to enter woodier environs to consume fruits like these rose hips.

Dusk and dawn during the short days of winter are the prime hunting times of a mammal specialist, the Short-eared Owl. Its presence in the lower Susquehanna valley is dependent on two dominant factors: extensive grassland habitat and an adequate population of the owl’s favored food, the Meadow Vole (Microtus pennsylvanicus). The Short-eared Owl’s requirements as a specialist species make finding a suitable place to live difficult. Unlike the generalist birds and mammals that often adapt to the widespread man-made disturbances in the region, populations of specialists frequently become fragmented, reduced in abundance, and subject to extirpation.

The Meadow Vole is a generalist rodent that can be abundant in grasslands, early successional growth, fallow fields, marshlands, and, of course, meadows. They are primarily herbivores, but will occasionally consume insects and other arthropods. Usually nocturnal, some individuals venture out along their surface runways during daylight hours becoming vulnerable to diurnal raptors including kestrels, harriers, and buteos.

Short-eared Owl patrolling a grassland for Meadow Voles — A Short-eared Owl in near darkness patrolling a grassland for Meadow Voles.

The eastward expansion of the Coyote (Canis latrans), a species of western North America’s grasslands and scrublands, and its progressive mixing with the Wolf (Canis lupus) in these eastern extensions of its range, has produced an expanding population of very adaptable generalists we call Eastern Coyotes (Canis latrans var.). These omnivorous canines colonized the Lower Susquehanna River Watershed during the last four decades to replace extirpated wolves as the top-tier natural predator in the region. Their primary diet includes Meadow Voles in grasslands and other small mammals along woodland edges and in successional habitats. Seasonally, they consume the berries of numerous wild plants. Slightly larger than their western ancestors, Eastern Coyotes with the admixture of Wolf genetics can subdue small ungulates. Like other apex predators, they are attracted to vulnerable prey and thus play a crucial role in culling the weak and diseased among their potential quarry species to assure the health and potential of populations of these species as long-term sources of food energy. The benefit to the prey species is however largely diluted in populous areas of the northeast; most venison consumed by Eastern Coyotes here is in the form of road kill. During periods of extended snow cover when small rodents and other foods become inaccessible, Eastern Coyotes, particularly young individuals, will wander into new areas seeking sustenance. Sometimes they venture into cities and suburbs where they explore the neighborhoods in search of garbage and pet foods placed outside the home. (Video clip courtesy of Tyler and Grace Good. Click image to view.)

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

Being an individual from a population of a very successful generalist species is no guarantee of survival. This Eastern Gray Squirrel fell from a tall tree when the limbs became ice covered during a storm earlier this month. Just a freak accident? Maybe, but mistakes like this are often fatal in the natural world. This squirrel’s passing may seem brutal, but it provides a better opportunity for other squirrels and animals that share its food and cover requirements to make it through the winter. And those survivors that didn’t suffer such a fatal mistake or, more importantly, don’t possess a vulnerability that may have contributed to such a mishap will have a chance to pass those traits on to a new generation. This squirrel as an individual is gone, its species lives on, and may be stronger for its passing.

Prescribed Burn of a Grassland — Pennsylvania Game Commission crews maintain a grassland ecosystem for Short-eared Owls and other specialists using prescribed fire to prevent succession beyond its earliest stages. Among the additional specialist species benefiting from this management tool are Monarchs and other butterflies whose host plants survive early-season fire, but not competition with woody vines, shrubs, trees, and invasive herbaceous growth.

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

The Allegheny Woodrat (Neotoma magister), a threatened species in Pennsylvania and a critically imperiled species in Maryland, is a habitat specialist requiring the forested rocky slopes, talus-flanked ridgetops, and caves of the Ridge and Valley Province for its nest sites and survival. Isolated populations survived within similar environs in the lower Susquehanna River valley’s Piedmont Province and on South Mountain through at least the first half of the twentieth century, but have since been extirpated. Human encroachment that fragments their habitat and promotes exposure to parasite-hosting mammals including the Raccoon (*Procyon lotor)*, carrier of the Raccoon Roundworm (Baylisascarius procyonis), could prove fatal to remaining populations of this native mammal. (National Park Service image by Rick Olsen)

The American Oystercatcher (Haematopus palliatus) is a specialist species that uses its highly adapted bill to feed on marine invertebrates including mollusks, few of which are actually oysters. Reliant upon tidal ecosystems for its survival, many of the seashore animals that make up this wader’s diet are themselves specialist species. Oystercatchers spend nearly their entire lives in tidal marshes or within the intertidal zone on beaches. They also frequent rocky jetties, particularly during high tide. This individual was photographed near the mouth of Chesapeake Bay in Northhampton County, Virginia, a location that, when the waters of the Atlantic started rising over 10,000 years ago, was the lower Susquehanna valley about 60 miles from the river’s mouth at present-day Norfolk Canyon along the edge of the continental shelf. Get the drift?

December 18, 2024December 19, 2024

Seven Reasons to Visit Middle Creek’s Willow Point Right Now

Here are 7 reasons why you, during the coming week or so, should consider spending some time at Willow Point overlooking the lake at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area.

REASON NUMBER ONE— Wildlife is at close quarters along the trail leading from the parking lot to Willow Point…

Look carefully and you may see one or more species of woodpeckers in the mature trees. We found this Yellow-bellied Sapsucker in a maple near the trail’s terminus at the Willow Point viewing area.

REASON NUMBER TWO— A variety of waterfowl species are lingering on ice-free sections of the lake surrounding Willow Point…

Noisy flocks of Tundra Swans and Canada Geese on open water at Willow Point.

Mallards — Mallard drakes near the point.

A small flock of Green-winged Teal feeding among the Mallards.

A flock of Northern Shovelers has been frequenting the shallows along the south side of Willow Point for at least two weeks.

Common Mergansers diving for benthic fare.

REASON NUMBER THREE— Bald Eagles are conspicuous, easily seen and heard…

REASON NUMBER FOUR— Northern Harriers have been making close passes over Willow Point as they patrol Middle Creek’s grasslands while hunting voles…

REASON NUMBER FIVE— The annual observance of the White-tailed Deity holidays may be drawing to a close for the gasoline and gunpowder gang, but for the supreme ungulates, the rituals that lead to consummation of their unions are still ongoing…

REASON NUMBER SIX— Sandhill Cranes are still being seen from Willow Point…

REASON NUMBER SEVEN— The crowds that will accompany the arrival of thousands of Snow Geese in early 2025 can make visiting Willow Point a stressful experience. Visit now to see these birds and mammals at Willow Point and you might just have the place all to yourself. Then you can spend your time looking through the flocks of waterfowl and other birds for unusual new arrivals instead of wading through a sea of humanity.

November 12, 2024November 14, 2024

A Visit to Hawk Mountain Sanctuary

Mid-November is our favorite time of year to visit Hawk Mountain Sanctuary on Blue Mountain/Kittatinny Ridge just to the east of the lower Susuquehanna valley near Kempton, Pennsylvania. By now, the huge crowds that come to see October’s world-famous raptor flights and spectacular fall foliage have dwindled to small groups of serious hawkwatchers and hardy trail enthusiasts. Join us as we drop in on the Keystone State’s most famous birding destination.

Hawk Mountain Sanctuary Entrance — The entrance to Hawk Mountain Sanctuary is located at 1700 Hawk Mountain Road off PA Route 895 east of PA Route 61.

Hawk Mountain Sanctuary Headquarters — Start your visit with a stop inside the refuge headquarters building where you’ll find raptor ecology and migration displays, a gift shop, and a window overlooking a busy bird-feeding station. Hawk Mountain is a non-profit organization that receives no taxpayer support and relies largely upon membership fees and donations for the majority of its operating expenses. Inside the headquarters building, you can pay dues and join on the spot.

Native Plant Garden — The native plant habitat includes a pond and a rain garden that collects stormwater from the roof of the headquarters building. There’s also a memorial fern garden named for the refuge’s first curator, Maurice Broun, author of a 1938 index to the ferns of North America.

Trail Sign — After a visit to the habitat garden, it’s time to make our way toward the lookouts.

PA Historical Marker, Hawk Mountain Sanctuary. — 2024 marks the 90th anniversary of the founding of Hawk Mountain Sanctuary. We stopped at the trail crossing along the mountain road to admire this newly erected sign.

Hawk Mounatin Sanctuary Trailhead Gate — Trail fees are collected to support the sanctuary’s operations and maintain its 2,600 acres. Members enter free.

Hawk Mountain Interpretive Kiosk — Interpretive signs and trail information are provided throughout the refuge, particularly along the mile-long climb to the North Lookout.

River of Rocks Trail — Aside from the route to the lookouts (along which sturdy shoes and good balance are a must), many of the sanctuary’s hiking trails require special equipment and preparations. Be certain to follow the posted guidelines.

Raptor education panels along the lookout trail. — The scope of Hawk Mountain’s educational mission includes topics ranging from local Appalachian natural history to global raptor conservation.

Hawk Mountain South Lookout — Just a few hundred yards from the entrance gate, South Lookout provides a panoramic view of the “River of Rocks” talus outcrop and beyond. On days with southerly winds, autumn raptor flights are sometimes enumerated from this location.

Hawk Mountain’s “classroom in the sky”, the North Lookout, hosts school and scout groups learning raptor identification and ecology. It’s the sanctuary’s primary location for counting thousands of migrating birds of prey each fall.

Students quickly learn to identify distant Turkey Vultures by their upturned wings held in a dihedral posture and by their rocking motion in flight.

Hawk Mountain North Lookout — After the pupils depart for the day, there are but few observers remaining to find and count passing hawks and eagles during mid-November.

While sitting quietly among the boulders of North Lookout waiting for the next bird to come along, one can be treated to a visit by one or more of a local population of Southern Red-backed Voles (Clethrionomys gapperi).

While you were busy looking up, the Southern Red-backed Vole was at your feet scarfing up the crumbs from your sandwich. When not availed of our leftovers, its diet includes seeds, various plant parts, and subterranean fungi.

Playful groups of Common Ravens often provide comic relief during interludes in the parade of migrants.

But late-season visitors really want to see a Golden Eagle. On a chilly day with gusty northwest winds, few are disappointed.

Hatch-year/juvenile American Goshawk — We got very lucky during a recent day on North Lookout, spotting this rarity, a hatch-year/juvenile American Goshawk (Accipiter atricapillus), a species which, in 2023, was split from the Northern Goshawk (Accipiter gentilis), a species which was simultaneously assigned the new common name Eurasian Goshawk. Even more recently, within the past several weeks, the genus name Astur has replaced Accipiter for the goshawks, now formally known as the the American Goshawk (Astur atricapillus) and the Eurasian Goshawk (Astur gentilis). The new classification includes Cooper’s Hawk in the genus Astur, while the Sharp-shinned Hawk remains in the genus Accipiter.

If the cold of mid-November doesn’t cramp your style, and if you’d like to seize your best opportunity for a much-coveted sighting of one or more of the late-season specialties, then now is the time to visit Hawk Mountain Sanctuary. Bring a cushion upon which to sit, dress in layers, pack a lunch, and plan to spend the day. You could be rewarded with memorable views of the seldom-encountered species some people spend years of their lives hoping to see.

To learn more, check out the Hawk Mountain Sanctuary website.

October 31, 2024October 31, 2024

Three’s Company

For many species of terrestrial vertebrates living in the lower Susquehanna valley, it’s time to take refuge in a safe place below ground to enter a winter-long slumber. The numerous frosty nights of the past two weeks have expedited the stragglers’ efforts to find a suitable place to pass our coldest months.

Wood Turtles — Aside from the Eastern Box Turtle (Terrapene carolina carolina), the Wood Turtle (Glyptemys insculpta) is our most terrestrial species of testudine, however it is seldom found far from wet bottomlands. Last week, we found this pair preparing to burrow into alluvial soils along the edge of a floodplain wetland where they will spend the winter. In recent years, Wood Turtle numbers have plummeted due to habitat fragmentation and loss, and due to collecting by short-sighted petkeepers and profiteers.

A sluggish Wood Turtle catching a few last rays of sunshine before digging in for the winter. If you encounter these or any turtles now or at any time of year, it’s important that they not be disturbed. Look and leave them be.

And now, just in time for Halloween, a look at some hibernating species that some of our more squeamish readers consider to be “scary”.

In the mountainous forests of the Ridge and Valley Province, there lives a seldom seen little mouse which, unlike the more familiar species found in the fields, farms, and homes of our valleys and Piedmont, spends almost half the year in true hibernation.

The Woodland Jumping Mouse (Napaeozapus insignis) is a nocturnal species of rodent found primarily on rocky forest slopes, particularly those with growths of Eastern White Pine and Eastern Hemlock. Unlike the similar White-footed Mouse, a species that sometimes enters homes in the fall and remains active year-round, the Woodland Jumping Mouse builds a small subterranean nest among rocks and boulders where it will enter a long winter slumber, often not emerging until the milder days of April. During the long hibernation, these mice sometimes fatally diminish the energy stored in their body fat; up to 75% may perish before spring arrives (Merritt, 1987).

In spring and fall, Eastern (Black) Ratsnakes are frequently seen basking in the sun as they absorb heat and get their metabolism going. During the hottest days of summer, when ambient air temperature is sufficient for their needs, they become nocturnal, hunting mice and other creatures that are also active at night. During October, they make their way back to a winter den where they will remain until March or April.

Eastern Ratsnake — A last-minute Eastern (Black) Ratsnake makes a slow late-October trek across a mountain road toward a winter den on the south slope of the ridge.

That’s right, all three of these snakes are known to cohabitate, not just during hibernation, but at other times of the year as well. And you thought they were mean and nasty to anything and everything in their path, didn’t you?

Here in the northeastern United States, fear of indigenous wild snakes is a totally irrational anxiety. It’s a figment of our indoctrination. Their wicked reputation is almost exclusively the result of a never-ending stream of demonizing propaganda from the pulpit, press, parents, panicked, and picture shows. All they want from you and I is to be left alone. Want something to really be afraid of this Halloween? Try domestic dogs. That’s right—the “friendly” pooch. In the United States, they’ll land hundreds of people in the emergency room today. Don’t like that one. How ’bout cars and trucks. They’ll kill and maim people all day long. And don’t forget about sugar. Yes friends, that sweet treat is pure poison that kills all day long. Happy Halloween!

SOURCES

Merritt, Joseph F. 1987. Guide to the Mammals of Pennsylvania. University of Pittsburgh Press. Pittsburgh, PA. pp.230-233.

Shaffer, Larry L. 1991. Pennsylvania Amphibians and Reptiles. Pennsylvania Fish Commission. Harrisburg, PA.

September 27, 2022

Photo of the Day

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