Disasters: The Big Three

August 3, 2025August 23, 2025

Today’s NOAA/GOES satellite image serves as a little reminder of the big three. That’s right, it’s the three big “natural” disasters—wildfires, inland flooding, and coastal flooding (lucky for us, our region is at present millions of years removed from severe threats posed by the tectonic disasters—earthquakes, volcanoes, and tsunamis—and is not particularly prone to frequent tornadoes). Each continues to cause an increasing volume of property damage and threaten a greater number of lives because of where and how we choose to make our homes and erect our structures.

Smoke from Canadian Wildfires and Tropical Storm Dexter — Earlier today, smoke from forest fires in central Canada sweeps through the skies of the Great Lakes, New England, and the Mid-Atlantic States north of the Mason-Dixon Line. Meanwhile off North Carolina, Tropical Storm Dexter is seen developing over warm ocean waters east of the Gulf Stream. (NOAA/GOES satellite image)

For all of human existence, the dynamics of the atmosphere have been shaping the topography and the ecosystems of the planet. In recent times, we’ve had the advantage of satellite technologies to show us spectacular images of atmospheric events as they happen. And through the various branches of science, we’ve come to understand the impact these events have upon the landscape and the people who live and/or work there.

Forestry sciences have helped us to understand how natural fuels, humidity, temperature, rainfall, soil moisture, wind, and human encroachment influence the frequency and severity of wildfires. These discoveries have led to changes in forest management and implementation of practices such as prescribed burns to reduce accumulated fuel loads. Because human development typically lowers soil moisture and brings along with it additional sources of ignition, many land managers and fire departments have warned of the ever increasing dangers of wildland-urban interface fires. These warnings have gone largely unheeded for more than four decades as millions of homes and other combustible structures have been erected within areas prone to fires capable of uncontrollable growth into disastrous conflagrations. The tinderbox wildlands—they’re a nice place to visit, but we ought not to live there!

Tropical storms and other sources of heavy precipitation bring about quite the hubbub over flooding. Meteorologists spend a lot of time explaining it all, but it’s almost as if no one pays any mind. For a people who check the weather forecast several times a day, every day of our adult life, just to get a leg up on how that weather is going to change day by day and hour by hour, you would think we would better anticipate the climatic events that happen over the long term. In particular, you would think we would have an awareness of our own individual susceptibility to flooding— a grasp of how, where, and why floods occur. You would think that repeated episodes of flooding would compel society to embrace an ethic that treated water as the valuable commodity it is. Yet, we all seem to follow the same patterns of behavior. First, we drain, dump, pipe, curb, channel, ditch, grade, pave, and pump to get the rain that falls upon our property off of our property. Then, the chump downstream gets really mad that we sent our water his way and flooded him out, so he takes the same measures to send even more water to the next poor slob down the line until finally the now polluted slurry of runoff floods the street, a cellar, a house, a business, or a stream—a stream that has been channelized so it no longer has a floodplain to absorb, hold, purify, and infiltrate the stormwater. Why was the stream channelized? So we could fill in the floodplain and build upon it of course. Two things come to mind here. First, if we’re going to be selfish enough to flood out our neighbors, then why shouldn’t we be totally selfish and keep for ourselves all the water that falls upon our place. After all, we’re going to need that water some day. And second, the floodplain is a nice place to visit, but we ought not to build there. Floodplains are for flooding; thousands of years of erosion have shaped them that way—it’s a gravity thing!

Next, we look at the lessons from geology, more specifically coastal geomorphology. Through these disciplines we know that the coastal plain—the flat land that spent most of the last 35.5 million years (the time since the meteor strike at the present-day mouth of Chesapeake Bay) as a beach or a tidal marsh—today stands mostly less than three dozen feet above sea level. We know that the sands forming barrier islands along the Atlantic seaboard, which are only several feet above sea level, shift their shape and position with the tides. Over the decades and centuries, these islands migrate and compensate for changes in climate and tidal patterns as well as sea levels. Behind their shifting dunes, vast tidal marshes are protected from seasonal storms including the periodic nor’easter or hurricane. Despite the importance of barrier island dynamics to the integrity of the bays and estuaries they protect, and despite their vulnerability to coastal storm surges, winds, and flooding, we choose to build there. In fact, the greatest population densities in the United States, and in many other countries of the world, are on the beach. It’s not because these hundreds of millions of people are fishing or loading/unloading ships for a living—it’s mostly for the view. Despite their importance to fisheries and other coastal life, we continue to alter and destroy the near-tidal areas of the the barrier islands and bays. We go to great expense to “save” for our uses the lands that should be getting inundated by rising sea levels to create new shallow tidewater zones. We waste spectacular amounts of money pumping sand back onto beaches to keep naturally migrating sediments from changing their shape and position in response to the tides. We keep putting more people and more capital at risk by urbanizing these low-lying areas. Building on the beach is absolute madness. It’s an ecological catastrophe from day one and a human catastrophe soon after.

All of the lands impacted by these natural events have two things in common. Each becomes a potential disaster area if people choose to construct their homes or businesses there. And each, if left in its wild state and given a buffer space from human activity, reacts with natural time-derived mechanisms in response to the same events. These mechanisms are often essential for provision of the unique ecosystems required by many of our most threatened wildlife species. Human encroachment into floodplains, wetlands, tidal marshes, beaches, and xeric uplands is a double-edged sword. It first decimates populations of these uncommon species by destroying and fragmenting their specialized habitats. Then, it sets the stage for the fires, floods, and other disasters that endanger the lives and property of the people living there. Considering the ramifications of building in these fire and flood susceptible areas, we can and should live somewhere else, especially when the wildlife requiring these places often can’t.

Sunset over the Susquehanna at Chiques Rock — This evening’s smoky sunset over the Susquehanna at Chiques Rock was courtesy of Canadian wildfires.

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.

The Hermit Thrush’s generalist lifestyle allows it to survive cold season weather in the Lower Susquehanna River Watershed. During summer, it breeds in coniferous and mixed woods from the northern parts of our valley north into Canada and feeds primarily on worms, insects, and other arthropods. During migration and in winter, the Hermit Thrush becomes a regular visitor to deciduous forests, woody parks and suburbs, particularly where a supply of wild berries is available to supplement its diet.

Iconic as it pulls earthworms from lawns during the warmer months, the generalist American Robin is fully dependent upon a crop of berries to survive winter conditions in the lower Susquehanna valley. The drought afflicted wild food crop of 2024 has led to fewer robins spending the season here and has delayed the northward push of migrating birds until the ground thaws and the earthworms make the ground rumble once again.

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?