During Saturday’s Prescribed Fire Demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area, we noticed just how fast some species of wildlife return to areas subjected to burns administered to maintain grassland habitat and reduce the risk of high-intensity blazes.
Pennsylvania Game Commission crews ignite a back fire to contain a prescribed burn along its downwind/upslope perimeter during a demonstration at Middle Creek Wildlife Management Area on Saturday.Visitors observe a fire planned to maintain this section of the refuge as warm-season grassland. A species with roots several feet deep, the light-colored vegetation is Indiangrass, a plant adapted to thrive following periodic episodes of wildfire. Prescribed fire can be used to replace naturally occurring infernos with much safer controlled burns that eliminate successional and invasive plants to promote the establishment of Indiangrass and other native warm-season species including Big Bluestem, Little Bluestem, Switchgrass, and a variety of wildflowers as well.Even as the fire reached its brief peak of intensity, we noticed birds already attracted to the site…Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.One even stopped by to have a look inside the kestrel nest box as fire approached the dry stand of goldenrod on the slope behind.Red-tailed Hawks and other raptors, including nocturnal owls, are frequently the first visitors attracted to the scene of a prescribed burn or wildfire. In grassland and successional habitats, they come looking for any vulnerable voles or mice that may be moving about looking for cover.
These three Eastern Meadowlarks spent the morning in the grassland areas adjacent to the prescribed fire site, mostly where a burn had been conducted one week prior. During the demonstration, one even perched and sang from the oak trees in the museum/visitor’s center parking lot.
Following the Prescribed Fire Demonstration, we decided to pay a visit to some of the parcels where burns had been administered one week earlier on the north side of Middle Creek’s main impoundment. We found a surprising amount of activity.
Apparently feeding upon slightly heat-treated seeds, sparrows were found by the dozens. White-crowned (left), White-throated (right), Song, and Savannah Sparrows were identified.This Downy Woodpecker was finding something to its liking among the scorched leaves, stems, and twigs.American Robins seem to find areas with lightly burnt vegetation and ash-dusted soil advantageous for finding invertebrates following a fire.We found this flock of Red-winged Blackbirds, Browned-headed Cowbirds, and a few European Starlings feeding throughout a grassland field cleared of early-successional growth by a prescribed fire administered one week ago.They seemed to favor gleaning seeds from among the lightly burned areas of the plot.Nearby, in an island of unburned grass in the same field, we found yet another Eastern Meadowlark, our fourth of the day. High-intensity agriculture, particularly early hay mowing and pesticide treatments, have mostly eliminated this and other grassland species from modern farms. Management practices like prescribed fire and delayed mowing (no spinning blades until at least early August) can maintain ideal grassland habitat for stunningly colorful blackbirds including nesting Eastern Meadowlarks, Bobolinks, and many other species as well.A male American Kestrel at a nest box located among Middle Creek’s warm-season and cool-season grassland habitats, the former maintained by prescribed fire, the latter by delayed mowing.
With relative humidity readings regularly dipping below 50%, the sunny days of March and early April are often some of the driest of the year. During recent weeks, these measurements have plunged to as low as 20%, levels not often observed in our region. As we’ve seen throughout the lower Susquehanna valley, windy weather and this extraordinarily dry air conspire to create optimal conditions for fast-spreading and often dangerous wildland fires.
On the brighter side, dry weather also provides the opportunity for foresters and other land managers to administer prescribed fire. These controlled burns are thoroughly planned to reduce accumulations of wildfire fuels and invigorate understory growth in forests. Their use also provides a number of effective methods for creating and maintaining wildlife habitats in non-forested areas.
Prescribed burns are currently underway on many state, federal, and privately-owned lands throughout the Lower Susquehanna River Watershed.
This Saturday, March 22, 2025, crews from the Pennsylvania Game Commission will be hosting a Prescribed Fire Demonstration at Middle Creek Wildlife Management Area in Lancaster/Lebanon Counties. The event begins at 10:00 AM in the refuge’s museum/visitor’s center parking area. A controlled burn to “reset” a parcel with early successional growth back to grassland will follow a presentation on prescribed fire uses, planning, safety, and implementation.
Prescribed fire treatment being used to prevent succession and maintain a warm-season grassland.Prescribed fire being administered to eliminate successional woody growth from a sedge-rush wetland.Pennsylvania Game Commission crews maintain a fire line along an area being burned to control invasive successional growth.To best prevent succession, a given area should be burned every three to five years, thus only one fifth to one third of an entire habitat need be subjected to treatment each year. To flee this year’s prescribed burn, this Eastern Cottontail simply hops across the fire break into an adjacent plot that will be unaffected in 2025.Hen and cockbird Ring-necked Pheasants feeding in a pre-plowed fire break furrow along the northern edge of a prescribed fire plot burned during a south wind. These birds entered and fed in the area less than an hour after the flames subsided.To provide refuge for evacuating animals, a completed prescribed burn leaves plenty of adjacent grassland acreage untouched. Within weeks, the fire area will be lush green and again hosting many species of wildlife for the breeding season. The scorch-free areas will each get a prescribed fire treatment sometime during the coming two to four years, the time period preceding this parcel’s next burn.
Don’t forget: Middle Creek Wildlife Management Area museum/visitor’s center parking lot on Saturday, March 22, 2025, at 10:00 AM. See you there!
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 (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.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……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……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.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.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 becomes 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?
With low relative humidity, gusty daytime breezes, and little or no rain in the forecast, many counties and local municipalities in the lower Susquehanna basin have enacted bans on open burning to prevent accidental wildfires. With these dangerous conditions prevailing, you know enough not to burn trash and leaves, or to carelessly discard ashes or smoking materials. And you’re smart enough to keep close watch on fires used for cooking and to keep them within approved enclosures such as a grill with a lid. But have you thought of eliminating another common form of ignition, this one originating from your car or truck? Your motor vehicle’s catalytic converter is hot enough to ignite dry leaves, grasses, and crop residues like corn shocks upon contact, so be extra careful where you park. Be certain that your pollution control device remains free and clear of combustibles!
Back on March 24th, we took a detailed look at the process involved in administering prescribed fire as a tool for managing grassland and early successional habitat. Today we’re going turn back the hands of time to give you a glimpse of how the treated site fared during the five months since the controlled burn. Let’s go back to Middle Creek Wildlife Management Area for a photo tour to see how things have come along…
Pennsylvania Game Commission crews administering prescribed fire on a grassland demonstration site back on March 16.By late May, native herbaceous perennial wildflowers including Joe-pye Weed had re-greened the site. One of the goals of the burn was to kill fire-sensitive woody plants, thus preventing the process of succession from reforesting the site.The scorched, lifeless remains of small trees and shrubs indicate that that goal was met.Because prescribed fire is administered in a mosaic pattern that permits some early successional growth to remain until the next burn, birds including this thicket-nesting Yellow-breasted Chat are able to take advantage of the mixed habitat during their breeding season in May and June.By August, the site is a haven for native plants and animals.The burn has promoted the growth and late-summer bloom of fire-tolerant native wildflowers and warm-season grasses……including Indiangrass,……Big Bluestem……Thin-leaved Coneflower (Rudbeckia triloba), a plant also known as Brown-eyed Susan,……and Joe-pye Weed, a plant butterflies find irresistible.Eastern Tiger Swallowtail collecting nectar from Joe-pye Weed.A black-morph Eastern Tiger Swallowtail collecting nectar from Spotted Knapweed (Centaurea steobe micranthos), a non-native invasive plant found growing in an area of the burn site missed by this year’s fire. While many non-native plants are unable to survive the flames and heat produced by prescribed fire, it isn’t an absolute cure-all. It doesn’t eliminate all invasive plants, it just keeps them from dominating a landscape by out-competing native species. Left unmanaged, Spotted Knapweed is a tough perennial invasive that can easily become one the species able to overtake a vulnerable grassland. It can be a stubborn survivor of some prescribed burns. On the plus side, butterflies really like it.By August, native grassland plants in the prescribed fire area were already providing an abundance of seeds for birds including this American Goldfinch.For larger birds like turkeys and pheasants, an abundance of Carolina Grasshoppers are providing a protein-dense food source in managed grasslands.And tiny flying insects, a nuisance to us as we take a stroll alongside the grasslands, are a meal taken on the wing by dragonflies including this Black Saddlebags.
Elsewhere around the refuge at Middle Creek, prescribed fire and other management techniques are providing high-quality grassland habitat for numerous species of nesting birds…
Bobolinks nested both in areas subjected to controlled burns……and in hay fields where mowing was delayed until the nesting season, including the fledging process, was completed earlier this month.As advertised, Grasshopper Sparrows nested in these fields as well.
We hope you enjoyed this short photo tour of grassland management practices. Now, we’d like to leave you with one last set of pictures—a set you may find as interesting as we found them. Each is of a different Eastern Cottontail, a species we found to be particularly common on prescribed fire sites when we took these images in late May. The first two are of the individuals we happened to be able to photograph in areas subjected to fire two months earlier in March. The latter two are of cottontails we happened to photograph elsewhere on the refuge in areas not in proximity to ground treated with a prescribed burn or exposed to accidental fire in recent years.
Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.
These first two rabbits are living the good life in a warm-season grass wonderland.
Eastern Cottontail at a site not subjected to any recent fire activity.Eastern Cottontail at a site not subjected to any recent fire activity.
Oh Deer! Oh Deer! These last two rabbits have no clock to track the time; they have only ticks. Better not go for a stroll with them Alice—that’s no wonderland! I know, I know, it’s time to go. See ya later.
The Aphrodite Fritillary (Speyeria aphrodite), also known simply as the Aphrodite, is a brush-footed butterfly of deciduous, coniferous, and mixed forests. We found this female in a grassland margin between woodlots where prescribed fire was administered during the autumn of 2022 to reduce accumulations of natural fuels and an overabundance of invasive vegetation. A goal of the burn was to promote the growth of native species including the violets (Viola species) favored as larval host plants by this and other fritillaries.
A female Aphrodite Fritillary collecting nectar from a thistle flower.
By the time these adult butterflies make their reproductive flights in late summer, the violets that serve as larval host plants have gone dormant. To find patches of ground where the violets will come to life in spring, the female Aphrodite Fritillary has an ability to sense the presence of dormant roots, probably by smell. Upon finding an area where suitable violets will begin greening up next year, she’ll deposit her eggs. The eggs overwinter, then hatch to feed on the tender new violet leaves of spring.
A female Aphrodite Fritillary. A prescribed burn, when administered during spring to manage fritillary habitat, is applied only to a portion of the land parcel each year to avoid decimating an entire population of the larvae during the first instar of their life cycle, a time when they are vulnerable to fire.Our female Aphrodite Fritillary busily gathers nutritious nectar to provide sufficient energy for the critical process of mating and egg production. What’s the thistle that this goddess of love and procreation is pollinating?…It’s a non-native invasive, the Bull Thistle (Cirsium vulgare), a species that readily colonizes new areas by producing an abundance of airborne seeds. Continued management of this site with periodic applications of prescribed fire will prevent Bull Thistle and other invasives from overtaking the habitat during coming years.
Here’s a native plant you don’t see very often, but Ruby-throated Hummingbirds have a knack for finding and adoring it within the limited habitat where it still exists.
Allegheny Vine (Adlumia fungosa), also known as Climbing Fumitory or Mountain Fringe, is a seldom-found biennial herbaceous plant in the poppy family (Papaveraceae). Both its divided leaves and drooping clusters of flowers might remind the observer of a more familiar member of the poppy family, the spring-blooming Dutchman’s Breeches. But unlike the low-growing Dutchman’s Breeches, Allegheny Vine ascends nearby shrubs and small trees with trailing stems that add a garland-like pizzazz to the summertime foliage.Seen here creeping atop a small Sassafras (Sassafras albidum) tree, Allegheny Vine seldom escapes notice by the Ruby-throated Hummingbird, a primary pollinator of the plant.Allegheny Vine grows on moist, rocky slopes and blooms in late summer, just in time to refuel migrating Ruby-throated Hummingbirds.
Not likely to thrive in deep forest cover, Allegheny Vine is a denizen of edge habitat. The species is dependent on some type of disturbance to maintain suitable growing conditions. The plants seen here were found flowering in an area that had experienced a fire prior to last year’s growing season. It is therefore quite possible that the fire completed the stratification process and triggered long-dormant seeds to germinate last spring or summer to develop a basal plant which matured and flowered during this second summer of the biennial’s growth. On a forested slope opposite this site, a first-ever prescribed burn was conducted in March of this year to eliminate accumulated fuel and replicate a natural fire cycle. With a little luck, this forest management approach may prompt additional long-dormant Allegheny Vine seeds to germinate and form basal plants this year for maturation in 2025. Without man-made disturbances, Allegheny Vine may remain viable as a species by enduring seed dormancy periods of 40-100 years or more between fires, lightning strikes, wind storms, ice accumulations, and other events which clear the canopy and encourage growth.
Many years in the making, Allegheny Vine nectar must be delectable because the hummers can’t leave it alone. And another plus, with a little help from prescribed fire, this native creeping plant seems to be holding its own while in direct competition with invasive Mile-a-minute Weed (leaves in lower right).
While in flower, this extensive stand of Princess Trees (Paulownia tomentosa) straddling Second Mountain north of Harrisburg might be mistaken for a series of boulder outcrops. Native to eastern Asia, the fast-growing Princess Tree has escaped cultivation to become naturalized in many parts of eastern North America. You’ll currently notice the showy purple blooms on many forested ridges and hilltops throughout the Lower Susquehanna River Watershed. Paulownia tomentosa is also known as the Phoenix Tree, a name derived from its ability, due to its extensive root system, to regenerate following fire. This fast-growing invasive therefore calls for measures in addition to prescribed burns for control within infected forests. Mechanical and/or chemical methods of removal are frequently required.
Homo sapiens owes much of its success as a species to an acquired knowledge of how to make, control, and utilize fire. Using fire to convert the energy stored in combustible materials into light and heat has enabled humankind to expand its range throughout the globe. Indeed, humans in their furless incomplete mammalian state may have never been able to expand their populations outside of tropical latitudes without mastery of fire. It is fire that has enabled man to exploit more of the earth’s resources than any other species. From cooking otherwise unpalatable foods to powering the modern industrial society, fire has set man apart from the rest of the natural world.
In our modern civilizations, we generally look at the unplanned outbreak of fire as a catastrophe requiring our immediate intercession. A building fire, for example, is extinguished as quickly as possible to save lives and property. And fires detected in fields, brush, and woodlands are promptly controlled to prevent their exponential growth. But has fire gone to our heads? Do we have an anthropocentric view of fire? Aren’t there naturally occurring fires that are essential to the health of some of the world’s ecosystems? And to our own safety? Indeed there are. And many species and the ecosystems they inhabit rely on the periodic occurrence of fire to maintain their health and vigor.
For the war effort- The campaign to reduce the frequency of forest fires got its start during World War II with distribution of this poster in 1942. The goal was to protect the nation’s timber resources from accidental or malicious loss due to fire caused by man-made ignition sources. The release of the Walt Disney film “Bambi” during the same year and the adoption of the Smokey the Bear mascot in 1944 softened the message’s delivery, but the public relations outreach continued to be a key element of a no-fire policy to save trees for lumber. Protection and management of healthy forest ecosystems in their entirety has only recently become a priority. (National Archives image)
Man has been availed of the direct benefits of fire for possibly 40,000 years or more. Here in the Lower Susquehanna River Watershed, the earliest humans arrived as early as 12,000 years ago—already possessing skills for using fire. Native plants and animals on the other hand, have been part of the ever-changing mix of ecosystems found here for a much longer period of time—millions to tens of millions of years. Many terrestrial native species are adapted to the periodic occurrence of fire. Some, in fact, require it. Most upland ecosystems need an occasional dose of fire, usually ignited by lightning (though volcanism and incoming cosmic projectiles are rare possibilities), to regenerate vegetation, release nutrients, and maintain certain non-climax habitat types.
But much of our region has been deprived of natural-type fires since the time of the clearcutting of the virgin forests during the eighteenth and nineteenth centuries. This absence of a natural fire cycle has contributed to degradation and/or elimination of many forest and non-forest habitats. Without fire, a dangerous stockpile of combustible debris has been collecting, season after season, in some areas for a hundred years or more. Lacking periodic fires or sufficient moisture to sustain prompt decomposition of dead material, wildlands can accumulate enough leaf litter, thatch, dry brush, tinder, and fallen wood to fuel monumentally large forest fires—fires similar to those recently engulfing some areas of the American west. So elimination of natural fire isn’t just a problem for native plants and animals, its a potential problem for humans as well.
Indiangrass (seen here), Switchgrass, Big Bluestem, and Little Bluestem are native species requiring periodic forms of disturbance to eliminate competition by woody plants. These warm-season grasses develop roots that penetrate deep into the soil, sometimes to depths of six feet or more, allowing them to survive severe drought and flash fire events. In the tall grass prairies, these extensive root systems allow these grasses to return following heavy grazing by roaming herds of American Bison (Bison bison). Without these habitat disturbances, warm season grasslands succumb to succession in about seven years. With their periodic occurrence, the plants thrive and provide excellent wildlife habitat, erosion control, and grazing forage.
To address the habitat ailments caused by a lack of natural fires, federal, state, and local conservation agencies are adopting the practice of “prescribed fire” as a treatment to restore ecosystem health. A prescribed fire is a controlled burn specifically planned to correct one or more vegetative management problems on a given parcel of land. In the Lower Susquehanna River Watershed, prescribed fire is used to…
Eliminate dangerous accumulations of combustible fuels in woodlands.
Reduce accumulations of dead plant material that may harbor disease.
Provide top kill to promote oak regeneration.
Regenerate other targeted species of trees, wildflowers, grasses, and vegetation.
Kill non-native plants and promote growth of native plants.
Prevent succession.
Remove woody growth and thatch from grasslands.
Promote fire tolerant species of plants and animals.
Improve habitat for rare species (Regal Fritillary, etc.)
Recycle nutrients and minerals contained in dead plant material.
Let’s look at some examples of prescribed fire being implemented right here in our own neighborhood…
Prescribed fires are typically planned for the dormant season extending from late fall into early spring with burns best conducted on days when the relative humidity is low.Prescribed fire is used regularly at Fort Indiantown Gap Military Reservation in Lebanon County, Pennsylvania, to keep accumulations of woody and herbaceous fuels from accumulating on and around the training range areas where live ordinance and other sources of ignition could otherwise spark large, hard-to-control wildfires.Prescribed fires replace the periodic natural burns that would normally reduce the fuel load in forested areas. Where these fuels are allowed to accumulate, south-facing slopes are particularly susceptible to extreme fires due to their exposure to the drying effects of intense sunlight for much of the year. The majority of small oaks subjected to treatment by the prescribed fire shown here will have the chance to regenerate without immediate competition from other species including invasive plants. The larger trees are mostly unaffected by the quick exposure to the flames. Note too that these fires don’t completely burn everything on the forest floor, they burn that which is most combustible. There are still plenty of fallen logs for salamanders, skinks, and other animals to live beneath and within.
A prescribed fire in late winter prevents this grassland consisting of Big Bluestem and native wildflowers from being overtaken by woody growth and invasive species. Fires such as this that are intended to interrupt the process of succession are repeated at least every three to five years.In its wildlife food plots, prescribed fire is used by the Pennsylvania Game Commission to prevent succession and control invasive species such as Multiflora Rose, instead promoting the growth of native plants.An example of a woodlot understory choked with combustible fuels and dense tangles of invasive Multiflora Rose. A forester has the option of prescribing a dose of dormant-season fire for a site like this to reduce the fuel load, top kill non-native vegetation, and regenerate native plants.A dose of prescribed fire was administered on this grassland to kill the woody growth of small trees beginning to overtake the habitat by succession.The Pennsylvania Game Commission employs prescribed fire at Middle Creek Wildlife Management Area and on many of their other holdings to maintain grasslands.Prescribed fire is used to eliminate invasive species including Multiflora Rose from grasslands at Middle Creek W.M.A. Annual burns on the property are conducted in a mosaic pattern so that each individual area of the grassland is exposed to the effects of fire only once every two to five years. Without fire or some type of mechanical or chemical intervention, succession by woody trees and shrubs would take hold after about seven years.Prescribed fire is planned for a fraction of total grassland acreage at Middle Creek W.M.A. each year. Another section of the mosaic is targeted in the following year and yet another in the year that follows that. Because burns are conducted in the spring, grassland cover is available for wildlife throughout the winter. And because each year’s fire burns only a portion of the total grassland acreage, wildlife still has plenty of standing grass in which to take shelter during and after the prescribed fire.Prescribed fire at Middle Creek W.M.A. provides grassland habitat for dozens of species of birds and mammals including the not-so-common Grasshopper Sparrow……and stocked Ring-necked Pheasants that do nest and raise young there.On a few sites in the Lower Susquehanna River Watershed , prescribed fire is being used to establish and maintain savanna-like grasslands. This one, located on a dry, south-facing slope near numerous man-made sources of ignition, can easily be dosed with periodic prescribed burns to both prevent succession and reduce fuel accumulations that may lead to a devastating extreme fire.One year following a prescribed burn, this is the autumn appearance of a savanna-like habitat with fire-tolerant Pitch Pine (Pinus rigida), Bear Oak, warm-season grasses, and a variety of nectar-producing wildflowers for pollinators. These ecosystems are magnets for wildlife and may prove to be a manageable fit on sun-drenched sites adjacent to man-made land disturbances and their sources of ignition.Savanna-like grasslands with oaks and other scattered large trees, some of them dead, make attractive nesting habitat for the uncommon Red-headed Woodpecker.Prescribed fire can benefit hungry Wild Turkeys by maintaining savanna-like grasslands for an abundance of grasshoppers and other insects in summer and improving the success of mast-producing oaks for winter.In the Lower Susquehanna River Watershed, the caterpillar of the rare Eastern Buck Moth feeds on the foliage of the Bear Oak, also known as the Scrub Oak, a shrubby species that relies upon periodic fire to eliminate competition from larger trees in its early successional habitat.Leaves of the Bear Oak in fall. The Bear Oak regenerates readily from top kill caused by fire.Reed Canary Grass (Phalaris arundinacea) is a native cool-season grass with a colorful inflorescence in spring. But given the right situation, it can aggressively overtake other species to create a pure stand lacking biodiversity. It is one of the few native species which is sometimes labelled “invasive”.Prescribed fire can be used to reduce an overabundance of Reed Canary Grass and its thatch in wetlands. Periodic burning can help restore species diversity in these habitats for plants and animals including rare species such as the endangered Bog Turtle (Glyptemys muhlenbergii).On the range areas at Fort Indiantown Gap in Lebanon County, Pennsylvania, disturbances by armored vehicles mimic the effects of large mammals such as the American Bison which periodically trampled grasses to prevent succession and the establishment of woody plants on its prairie habitat. To supplement the activity of the heavy vehicles and to provide suitable habitat for the very rare Regal Fritillary (Speyeria idalia) butterflies found there, prescribed fire is periodically employed to maintain the grasslands on the range. These burns are planned to encourage the growth of “Fort Indiantown Gap Little Bluestem” grass as well as the violets used as host plants by the Regal Fritillary caterpillars. These fires also promote growth of a variety of native summer-blooming wildflowers to provide nectar for the adults butterflies.A last record of a wild American Bison killed in Pennsylvania was an animal taken in the Susquehanna watershed in Union County in 1801. The species is thereafter considered extirpated from the state. Since that time, natural disturbances needed to regenerate warm-season grasses have been limited primarily to fires and riverine ice scour. The waning occurrence of both has reduced the range of these grasses and their prairie-like ecosystems in the commonwealth. (Exhibit: State Museum of Pennsylvania, Harrisburg)A male Regal Fritillary on the range at Fort Indiantown Gap, where armored vehicles and prescribed fire provide suitable prairie-like habitat for this vulnerable species.Prescribed fires return the nutrients and minerals contained in dead plant material to the soil. Following these controlled burns, insects like this Honey Bee can often be seen collecting minerals from the ashes.A Greenbottle Fly gathering minerals from the ash following a prescribed burn.
In Pennsylvania, state law provides landowners and crews conducting prescribed fire burns with reduced legal liability when the latter meet certain educational, planning, and operational requirements. This law may help encourage more widespread application of prescribed fire in the state’s forests and other ecosystems where essential periodic fire has been absent for so very long. Currently in the Lower Susquehanna River Watershed, prescribed fire is most frequently being employed by state agencies on state lands—in particular, the Department of Conservation and Natural Resources on State Forests and the Pennsylvania Game Commission on State Game Lands. Prescribed fire is also part of the vegetation management plan at Fort Indiantown Gap Military Reservation and on the land holdings of the Hershey Trust. Visitors to the nearby Gettysburg National Military Park will also notice prescribed fire being used to maintain the grassland restorations there.
For crews administering prescribed fire burns, late March and early April are a busy time. The relative humidity is often at its lowest level of the year, so the probability of ignition of previous years’ growth is generally at its best. We visited with a crew administering a prescribed fire at Middle Creek Wildlife Management Area last week. Have a look…
Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire and the equipment and techniques they use to conduct a burn.Pennsylvania Game Commission Southeast Region Forester Andy Weaver will fulfill the role of Burn Boss for administering this day’s dose of fire. His responsibilities include assessing the weather before the burn and calculating a probability of ignition.The Burn Boss briefs personnel with information on site layout, water supply location(s), places of refuge, emergency procedures, the event’s goals and plan of action, crew assignments, and the results of the weather check: wind from the northwest at 5 miles per hour, temperature 48 degrees, and the relative humidity 63%. Today’s patient is a parcel of warm-season grasses receiving a dose of fire to eliminate invasive non-native plants, woody growth, and thatch. The probability of ignition is 20%, but improving by the minute.To begin the burn, a test fire is started in the downwind corner of the parcel, which also happens to be the bottom of the slope. Fuel ignition is good. The burn can proceed.Crews proceed uphill from the location of the test fire while igniting combustibles along both flanks of the area being treated.A drip torch is used to ignite the dried stems and leaves of warm-season grasses and wildflowers. Each member of the burn crew wears Nomex fire-resistant clothing and carries safety equipment including a two-way radio, a hydration pack, and a cocoon-like emergency fire shelter.An all-terrain vehicle equipped with various tools, a fire pump, hose, and a small water tank accompanies the crew on each flank of the fire.A mowed strip of cool-season grasses along the perimeter of the burn area is already green and functions as an ideal fire break. While the drip torch is perfect for lighting combustibles along the fire’s perimeter, the paintball gun-looking device is an effective tool used to lob incendiaries into the center areas of the burn zone for ignition.With green cool-season grasses already growing on the trails surrounding the burn zone, very little water was used to contain this prescribed fire. Where such convenient fire breaks don’t already exist, crews carry tools including chain saws, shovels, and leaf blowers to create their own. They also carry flame swatters, backpack water pumps, shovels, and other tools to extinguish fires if necessary. None of these items were needed to control this particular fire.This fast-burning fire provides enough heat to damage the cambium layer of the woody tree and shrub saplings in this parcel being maintained as a grassland/wildflower plot, thus the process of succession is forestalled. Burns conducted during previous years on this and adjacent fields have also controlled aggressive growth of invasive Multiflora Rose and Olives (Elaeagnus species).Crews proceed up the slope while maintaining the perimeter by igniting dry plant material along the flanks of the burn zone.Ignition complete, the crews monitor the fire.The Burn Boss surveys the final stages of a safe and successful prescribed fire. The fire has left behind a mosaic of burned and unburned areas, just as a naturally occurring event may have done. Wildlife dodging the flames may be taking refuge in the standing grasses, so there is no remedial attempt to go back and ignite these areas. They’ll be burned during prescribed fires in coming years.By June, this grassland will again be lush and green with warm-season grasses and blooming wildflowers like this Common Milkweed being visited by a Great Spangled Fritillary.And later in the summer, Eastern Tiger Swallowtails on Joe-pye Weed.Indiangrass in flower in mid-summer.Bobolinks glow in the late August sun while taking flight from a stand of warm-season grasses maintained using springtime prescribed fire. The small dots on the dark background at the top of the image are multitudes of flying insects, many of them pollinators. The vegetation is predominately Indiangrass, excellent winter cover for birds, mammals, and other wildlife.
Prescribed burns aren’t a cure-all for what ails a troubled forest or other ecosystem, but they can be an effective remedy for deficiencies caused by a lack of periodic episodes of naturally occurring fire. They are an important option for modern foresters, wildlife managers, and other conservationists.
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.
It’s sprayed with herbicides. It’s mowed and mangled. It’s ground to shreds with noisy weed-trimmers. It’s scorned and maligned. It’s been targeted for elimination by some governments because it’s undesirable and “noxious”. And it has that four letter word in its name which dooms the fate of any plant that possesses it. It’s the Common Milkweed, and it’s the center of activity in our garden at this time of year. Yep, we said milk-WEED.
Now, you need to understand that our garden is small—less than 2,500 square feet. There is no lawn, and there will be no lawn. We’ll have nothing to do with the lawn nonsense. Those of you who know us, know that the lawn, or anything that looks like lawn, are through.
Anyway, most of the plants in the garden are native species. There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed. The unusually wet growing season in 2018 has been very kind to these plants. They are still very green and lush. And the animals that rely on them are having a banner year. Have a look…
The flowers of the Common Milkweed were exceptionally fragrant this year. At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into our building and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from our walls (100 feet from his).Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species). The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases. Are you following this? Remember as we proceed, milkweed is “noxious”.Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.Following the pollination of the flowers, seed pods will begin to grow. We trim these off the plants. The removal of the extra weight allows most of the stems to remain erect through stormy weather. You’ll still get new plants from underground runners. As you may have guessed, we’re trying to keep these plants upright and strong to host Monarch butterfly larvae.
We’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects. This year, these plants are exceptionally colorful for late-August due to the abundance of rain. The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.
Big Bluestem, a native warm-season grass in flower.Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower. This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the herd animals and fires of the prairie to prevent succession and allow it to thrive.Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.Indiangrass (Sorghastrum nutans) in flower. This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA). They have an unbelievably large selection of indigenous species. You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea). Yes, it is that Echinacea, the same one used as a supplement and home remedy.
There was Monarch activity in the garden today like we’ve never seen before—and it revolved around milkweed and the companion plants.
A female Monarch laying eggs on a Common Milkweed leaf.A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf. Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf. There were over thirty of these caterpillars in just a ten by ten feet area this morning. We hope that if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant. Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle. Need more milkweed!After benefiting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.Two hours later, the chrysalis is complete.Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one. An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.There it is, soon ready to fly away. And all courtesy of the noxious milkweed.A chrysalis can often be found on man-made objects too. This one is on the rim of a flower pot.Ornamental flowers can attract adult Monarch butterflies seeking nectar. We’re now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides. There’s growing concern over the impact these compounds may be having on pollinating species of animals. Oh…and we don’t mow, whack, cut, mutilate, or spray herbicides on our milkweed, but you probably figured that out already.
SOURCES
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York.
