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…
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…
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.
These first two rabbits are living the good life in a warm-season grass wonderland.
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.
During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest. Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.
Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars. All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.
In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent. There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard. One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young. That could very well be true—but consider timing.
So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars? Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.
Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site. For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat. For us, they can be great places to see and hear colorful birds.
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.
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.
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…
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…
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.
Grasshoppers are perhaps best known for the occasions throughout history when an enormous congregation of these insects—a “plague of locusts”—would assemble and rove a region to feed. These swarms, which sometimes covered tens of thousands of square miles or more, often decimated crops, darkened the sky, and, on occasion, resulted in catastrophic famine among human settlements in various parts of the world.
The largest “plague of locusts” in the United States occurred during the mid-1870s in the Great Plains. The Rocky Mountain Locust (Melanoplus spretus), a grasshopper of prairies in the American west, had a range that extended east into New England, possibly settling there on lands cleared for farming. Rocky Mountain Locusts, aside from their native habitat on grasslands, apparently thrived on fields planted with warm-season crops. Like most grasshoppers, they fed and developed most vigorously during periods of dry, hot weather. With plenty of vegetative matter to consume during periods of scorching temperatures, the stage was set for populations of these insects to explode in agricultural areas, then take wing in search of more forage. Plagues struck parts of northern New England as early as the mid-1700s and were numerous in various states in the Great Plains through the middle of the 1800s. The big ones hit between 1873 and 1877 when swarms numbering as many as trillions of grasshoppers did $200 million in crop damage and caused a famine so severe that many farmers abandoned the westward migration. To prevent recurrent outbreaks of locust plagues and famine, experts suggested planting more cool-season grains like winter wheat, a crop which could mature and be harvested before the grasshoppers had a chance to cause any significant damage. In the years that followed, and as prairies gave way to the expansive agricultural lands that presently cover most of the Rocky Mountain Locust’s former range, the grasshopper began to disappear. By the early years of the twentieth century, the species was extinct. No one was quite certain why, and the precise cause is still a topic of debate to this day. Conversion of nearly all of its native habitat to cropland and grazing acreage seems to be the most likely culprit.
In the Mid-Atlantic States, the mosaic of the landscape—farmland interspersed with a mix of forest and disturbed urban/suburban lots—prevents grasshoppers from reaching the densities from which swarms arise. In the years since the implementation of “Green Revolution” farming practices, numbers of grasshoppers in our region have declined. Systemic insecticides including neonicotinoids keep grasshoppers and other insects from munching on warm-season crops like corn and soybeans. And herbicides including 2,4-D (2,4-Dichlorophenoxyacetic acid) have, in effect, become the equivalent of insecticides, eliminating broadleaf food plants from the pasturelands and hayfields where grasshoppers once fed and reproduced in abundance. As a result, few of the approximately three dozen species of grasshoppers with ranges that include the Lower Susquehanna River Watershed are common here. Those that still thrive are largely adapted to roadsides, waste ground, and small clearings where native and some non-native plants make up their diet.
Here’s a look at four species of grasshoppers you’re likely to find in disturbed habitats throughout our region. Each remains common in relatively pesticide-free spaces with stands of dense grasses and broadleaf plants nearby.
CAROLINA GRASSHOPPER
Dissosteira carolina
DIFFERENTIAL GRASSHOPPER
Melanoplus differentialis
TWO-STRIPED GRASSHOPPER
Melanoplus bivittatus
RED-LEGGED GRASSHOPPER
Melanoplus femurrubrum
Protein-rich grasshoppers are an important late-summer, early-fall food source for birds. The absence of these insects has forced many species of breeding birds to abandon farmland or, in some cases, disappear altogether.
Looking for a native wildflower that’s tall, showy, and a great choice for attracting wildlife, especially butterflies and bees? Then check out Wild Senna (Senna hebecarpa).
Wild Senna, also known as American Senna, is a host plant for the larvae of Cloudless Sulphur and Sleepy Orange (Eurema nicippe) butterflies. It thrives in almost any moist, well-drained soil in habitats including open woodlands, forest edges, meadows, and gardens like yours. Its height at flowering ranges from three to six feet. If you prefer, this perennial wildflower can even be cultivated as a shrub-like form. It is easily grown from seed, which is available from Ernst Conservation Seeds of Meadville, Pennsylvania, as well as numerous other vendors. And don’t forget to give Wild Senna’s two close relatives, Partridge Pea and Maryland Senna, a try as well. They attract the same species of butterflies and are just as easy to grow. You’ll like ’em.
Here in a series of photographs are just a handful of the reasons why the land stewards at Middle Creek Wildlife Management Area and other properties where conservation and propagation practices are employed delay the mowing of fields composed of cool-season grasses until after August 15 each year.
Right now is a good time to visit Middle Creek Wildlife Management Area to see the effectiveness a delayed mowing schedule can have when applied to fields of cool-season grasses. If you slowly drive, walk, or bicycle the auto tour route on the north side of the lake, you’ll pass through vast areas maintained as cool-season and warm-season grasses and early successional growth—and you’ll have a chance to see these and other grassland birds raising their young. It’s like a trip back in time to see farmlands they way they were during the middle years of the twentieth century.
Have you purchased your 2023-2024 Federal Duck Stamp? Nearly every penny of the 25 dollars you spend for a duck stamp goes toward habitat acquisition and improvements for waterfowl and the hundreds of other animal species that use wetlands for breeding, feeding, and as migration stopover points. Duck stamps aren’t just for hunters, purchasers get free admission to National Wildlife Refuges all over the United States. So do something good for conservation—stop by your local post office and get your Federal Duck Stamp.
Still not convinced that a Federal Duck Stamp is worth the money? Well then, follow along as we take a photo tour of Bombay Hook National Wildlife Refuge. Numbers of southbound shorebirds are on the rise in the refuge’s saltwater marshes and freshwater pools, so we timed a visit earlier this week to coincide with a late-morning high tide.
As the tide recedes, shorebirds leave the freshwater pools to begin feeding on the vast mudflats exposed within the saltwater marshes. Most birds are far from view, but that won’t stop a dedicated observer from finding other spectacular creatures on the bay side of the tour route road.
No visit to Bombay Hook is complete without at least a quick loop through the upland habitats at the far end of the tour route.
We hope you’ve been convinced to visit Bombay Hook National Wildlife Refuge sometime soon. And we hope too that you’ll help fund additional conservation acquisitions and improvements by visiting your local post office and buying a Federal Duck Stamp.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY NINE—May 29, 1983
“Falcon Dam State Park, Texas”
“To the spillway area after breakfast and saw Ringed Kingfisher, Baird’s Sandpiper, and 2 Black-necked Stilts. Stopped to photograph the Swainson’s Hawk which had flown in a tree. Also saw a Blue Grosbeak.”
The Ringed Kingfisher (Megaceryle torquata) was notably larger than the Belted Kingfishers with which we were so familiar, so it was easy to identify. This was yet another tropical species found north only as far as the Rio Grande Valley of Texas. Baird’s Sandpiper was a pretty good find for this location in late May.
“We drove to Santa Margarita Ranch to search for the elusive Brown Jay.”
While en route to Santa Margarita Ranch, we stopped twice to photograph birds we spotted along the way.
Beside the road just outside the entrance to the ranch, we observed a Verdin (Auriparus flaviceps), a tiny chickadee-like like bird with a yellow head and throat. Verdins reside in both thornscrub and desert throughout the southwestern United States and northern Mexico.
“Rancho Santa Margarita is a group of 8 houses. Cattle roam at will. We walked a long way along the river — No luck. Had lunch in the camper and repeated the morning walk. Cattle dung all over the place. The dung rollers were as interesting to watch as the leaf-carrying ants. Met a Mr. McQueary who had seen them 30 min. ago, so he led us to where he had seen them, but — No luck.”
Upon arriving at Santa Margarita Ranch intending to find Brown Jays (Psilorhinus morio), we drove over the in-ground cattle gate at the entrance and back the dirt driveway to the small cluster of houses where we parked. We checked in with a resident there and slipped them a dollar or two a head for letting us spend the day on their land. As we walked away from the houses, we noticed some intermittent movement in a pile of construction debris along the dirt road leading to the river. Initially thinking we may have caught glimpses of some small rodents dashing around, we watched patiently until we saw at least two Blue Spiny Lizards (Sceloporus cyanogenys) among the lumber and tin. The pair was obviously finding insects or other sources of prey there
To find Brown Jays, one of the five target species of the trip, Father Tom had advised us to follow the advice in James Lane’s A Birder’s Guide to the Rio Grande Valley of Texas. The recommendations contained therein brought us to Santa Margarita Ranch. As was the case upriver near Falcon Dam, the Tamaulipan Saline Thornscrub that covers much of the property turns abruptly to subtropical riparian forest near the banks of the Rio Grande where wetter soils predominate. The habitat was excellent, and we were certain the birds were there, but despite significant effort, we just couldn’t bump into Brown Jays at Santa Margarita Ranch.
We did however get good looks at another Hook-billed Kite sailing above the trees downriver. During our second walk, Harold, Steve, and I waded down a short section of the Rio Grande in hopes of getting better looks into an area of shoreline forest too thick to enter by land. Despite recent rains, the water was low, restricted by gates at Falcon Dam to little more than the flow needed to operate the turbines and generate electricity. We saw orioles, Red-billed Pigeon, and Great Kiskadee—but no Brown Jays.
“On the way out…found a nest of Pyrrhuloxia and saw a 6 ft. snake hanging from a bush with a rabbit in his mouth. The snake caught the rabbit by the shoulder and it was working hard to get free. Finally the snake dropped the rabbit, and they both went out of sight.”
As we eased our way out the dirt road at Santa Magarita Ranch, we began hearing a blood-curdling series of squeals. Russ stopped the van and as we peered into the thornscrub, we could catch glimpses of an Eastern Cottontail thrashing around. At first we thought it had somehow become snagged in the quagmire of prickles on the dense vegetation. Then we spotted the snake draped over the shrubs and attempting in vain to lift the cottontail off the ground. The struggle, and the squealing, continued for several minutes as we labored to identify the snake. As the snake attempted to reposition the cottontail so that it could swallow it head first, the rabbit broke free and escaped. All was silent as the snake quickly fled as well. As it slithered away we could see just how long it really was—5 to 6 feet or more. You know, things really are bigger in Texas. Based upon its large size, overall tan-brown color, and the rapid speed with which it left the scene, we determined it was a Western Coachwhip (Masticophis flagellum testaceus).
“Back to the spillway at Falcon Dam — No luck. Met Ron Huffman who is leading a trip for 3 women. We will meet him at the spillway tomorrow AM early. Back at our camp site for supper — shower and shave. The Lesser Nighthawks were trilling late in the evening.”
During the evening, we found Black-throated Sparrow (Amphispiza bilineata) and Scaled Quail (Callipepla squamata) in the area of the campsite. Then, as darkness settled in, the calls of Common Pauraque, Common Nighthawks, and Lesser Nighthawks (Chordeiles acutipennis) commenced. We walked down the road to a spot where we could overlook a lower-lying area of thornscrub in hopes of catching a glimpse of some of these nightjars, particularly the latter species, as they patrolled for flying insects. But under cloudy skies and being miles from any man-made sources of light, it was too dark to see anything flying around.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY FOUR—May 24, 1983
“AOK Campground—South of Kingsville, Texas”
“Arose at 6:30 A.M. to the tune of Common Nighthawks. After breakfast, we headed for Harlingen. While driving south we saw six pairs of Black-bellied Whistling Ducks. At Harlingen we phoned Father Tom, who is an expert birder for the area.”
As we drove south to Harlingen, much our 100-mile route was through the Laureles division of the King Ranch, the largest ranch in the United States. It covers over 800,000 acres and is larger than the state of Rhode Island. The road there was as straight as an arrow with wire fences on both sides and scrubland as far as the eye could see. Things really are bigger in Texas.
Once in Harlingen, we did two things no one needs to do anymore:
Find a coin-operated telephone to place a call to Father Tom.
Ask Father Tom for the latest tips on the locations of rare and/or target birds.
Today, nearly everyone traveling such distances to find birds is carrying a cellular phone and many can use theirs to access internet sites and databases such as eBird to get current sighting information. Back in 1983, Father Tom Pincelli was a dear friend to birders visiting the Lower Rio Grande Valley. Few places had a person who was willing to answer the phone and field inquiries regarding the latest whereabouts of this or that bird. To remain current, he also had to religiously (forgive me for the pun) collect sighting information from the observers with whom he had contact. For locations elsewhere across the country, a birder in 1983 was happy just to have a phone number for a hotline with a tape-recorded message listing the unusual sightings for its covered region. If you were lucky, the volunteer logging the sightings would be able to update the tape once a week. For those who dialed his number, Father Tom provided an exceptionally personal experience.
Since 1983, Father Tom Pincelli, also known as “Father Bird”, has tirelessly promoted birding and conservation throughout the Lower Rio Grande Valley. His efforts have included hosting a P.B.S. television program and writing columns for local newspapers. He has been instrumental in developing the annual Rio Grande Valley Birding Festival. The public sentiment he has generated for the birding paradise that is the Lower Rio Grande Valley has helped facilitate the acquisition and/or protection of many key parcels of land in the region.
“After receiving information on locations of Tropical Parula, Ferruginous Pygmy Owl, Hook-billed Kite, Brown Jay, and Clay-colored Robin, we went on to check out the Brownsville Airport where we will meet Harold and Steve Thursday noon.”
If we were going to see these five species in the American Birding Association listing area, then we would have to see them in the Lower Rio Grande Valley. All five were target birds for each of us, including Harold who had few other possibilities for new species on the trip. Father Tom provided us with tips for finding each.
I noticed as we began moving around Harlingen and Brownsville that Russ was swiftly getting his bearings—he had been here before and was starting to remember where things were. His ability to navigate his way around allowed us to keep moving and see a lot in a short time.
In Harlingen, we easily found Mourning Doves and the non-native Rock Pigeons, species we see regularly in Pennsylvania. We became more enthusiastic about doves and pigeons soon after when we saw the first of the several other species native to south Texas, the diminutive Inca Dove (Columbina inca), also known as the Mexican Dove.
“Next, to the Brownsville Dump to see the White-necked Ravens — Then to Mrs. Benn’s in Brownsville for the Buff-bellied Hummingbird. Both lifers for Larry.”
For birders wanting to see a White-necked Raven in the Lower Rio Grande Valley, the Brownsville Dump was the place to go. With very little effort—excluding a trip of nearly 2,000 miles to get there—we found them. Today, birders still go to the Brownsville Dump to find White-necked Ravens, though the dump is now called the Brownsville Landfill and the bird is known as the Chihuahuan Raven (Corvus cryptoleucus).
Mrs. Benn’s home was in a verdant residential neighborhood in Brownsville. She welcomed birders to come and see the Buff-bellied Hummingbirds that visited her feeder filled with sugar water. I don’t recall whether or not she kept a guest book for visitors to sign, but if she did, it would have included hundreds—maybe thousands—of names of people from all over North America who came to her garden to get a look at a Buff-bellied Hummingbird. After arriving, we waited a short time and sure enough, we watched a Buff-bellied Hummingbird (Amazilia yucatanensis) sipping Mrs. Benn’s home-brewed nectar from her glass feeder. This emerald hummingbird is primarily a Mexican species with a breeding range that extends north into the Lower Rio Grande Valley of Texas. When not breeding, a few will wander north and east along the Gulf Coastal Plain as far as Florida.
Other finds at Mrs Benn’s included White-winged Dove (Zenaida asiatica), Ash-throated Flycatcher (Myiarchus cinerascens), Brown-crested Flycatcher (Myiarchus tyrannulus), and Black-crested Titmouse (Baeolophus atricristatus), a species also known as Mexican Titmouse.
The Lower Rio Grande Valley from Rio Grande City east to the Gulf of Mexico is actually the river’s outflow delta. At least six historic channels have been delineated in Texas on the north side of the river’s present-day course. An equal number may exist south of the border in Mexico. Hundreds of oxbow lakes known as “resacas” mark the paths of the former channels through the delta. Many resacas are the centerpieces of parks, wildlife refuges, and housing developments. Still others are barely detectable after being buried in silt deposits left by the meandering river. Channelization, land disturbances related to agriculture, and a boom in urbanization throughout the valley have disconnected many of the most recently formed resacas from the river’s floodplain, preventing them from absorbing the impact of high-water events. These alterations to natural morphology can severely aggravate flooding and water pollution problems.
“On to Santa Ana National Wildlife Refuge. We walked to Pintail Lake and saw 6 Black-bellied Whistling Ducks and 2 Mississippi Kites and 1 Pied-billed Grebe. We drove the route thru the park with great results—Anhingas, Least Grebe, and more Black-bellied Whistling Ducks.
Santa Ana National Wildlife Refuge on the Rio Grande is not only a birder’s mecca, 300 species of butterflies have been identified there. That’s half the species known to occur in the United States! Its subtropical riparian forest and resaca lakes provide habitat for hundreds of migratory and resident bird species including many Central and South American species that reach the northern limit of their range in the Lower Rio Grande Valley. Two endangered cats occur in the park—the Ocelot (Leopardus pardalis) and the Jaguarundi (Herpailurus yagouaroundi).
We saw no cats at Santa Ana, but did quite well with the birds. Our list included the species listed above plus Cattle Egret (Bubulcus ibis); Louisiana Heron, now known as Tricolored Heron (Egretta tricolor); Plain Chachalacas; Purple Gallinule; Common Gallinule (Gallinula galeata); American Coot; Killdeer; Greater Yellowlegs; the coastal Laughing Gull (Leucophaeus atricilla); and its close relative of the central flyway and continental interior, the Franklin’s Gull (Leucophaeus pipixcan). Others finds were White-winged Dove, Mourning Dove, Inca Dove, Yellow-billed Cuckoo, Golden-fronted Woodpecker, Ladder-backed Woodpecker (Dryobates scalaris), Brown-crested Flycatcher, Altamira Oriole, Great-tailed Grackle, and House Sparrow. A real standout was the colorful Green Jay (Cyanocorax luxosus), yet another tropical Central American species found north only as far as the Lower Rio Grande Valley.
“We were unlucky not to find a campground at McAllen, so we went on to Bentsen State Park where we got a camp spot. After a sauerkraut supper, we birded till dark, then showered and wrote up the log. Very hot today.”
Bentsen-Rio Grande Valley State Park, like the Santa Ana National Wildlife Refuge, is located along the Rio Grande river and features dense subtropical riparian forest that grows in the naturally-deposited silt levees of the floodplain surrounding several lake-like oxbow resacas. Montezuma Bald Cypress (Taxodium mucronatum) is a native specialty found there but nowhere north of the Lower Rio Grande Valley. During our visit, we marveled at the epiphyte Spanish Moss (Tillandsia usneoides) adorning many of the more massive trees in the park. Willows lined much of the river shoreline.
Over time, flood control projects such as man-made dams, drainage ditches, and levees have impaired stormwater capture and aquifer recharge in the floodplain. These alterations to watershed hydrology have resulted in drier soils in many sections of the Lower Rio Grande Valley’s riparian forests. Where drier conditions persist, xeric (dry soil) scrubland plants are slowly overtaking the moisture-dependent species. As a result, the park’s woodlands are composed of trees with a variety of microclimatic requirements—Anaqua (Ehretia anacua), Cedar Elm (Ulmus crassifolia), Texas Ebony (Ebenopsis ebano), hackberry, mesquite, Mexican Ash (Fraxinus berlandieriana), retama, and tepeguaje are the principle species. The park’s subtropical Texas Wild Olive (Cordia boissieri) grows in the wild nowhere north of the Lower Rio Grande Valley.
While a majority of birders visiting Benten-Rio Grande State Park come to see the more tropical specialties of the riparian woods, searching the brushy habitat of the park’s scrubland can afford one the opportunity to see species typical of the southwestern United States and deserts of Mexico. This scrubland of the Lower Rio Grande Valley is part of the Tamaulipan Mezquital ecoregion, an area of xeric (dry soil) shrublands and deserts that extends northwest from the delta through most of south Texas and into the bordering provinces of northeastern Mexico.
Our campsite was located in prime birding habitat. We were a short walk away from one of the park’s flooded oxbow resacas and vegetation was thick along the roadsides. It was no surprise that the place abounded with birds. An evening stroll yielded Plain Chachalaca, White-winged Dove, Mourning Dove, White-fronted Dove, Golden-fronted Woodpecker, Brown-crested Flycatcher, Green Jay, Altamira Oriole, Great-tailed Grackle, and Bronzed Cowbird (Molothrus aeneus). At nightfall, we listened to the calls of an Eastern Screech Owl (Megascops asio), Common Nighthawks, and Common Pauraque (Nyctidromus albicollis), a nightjar of Central and South America that nests only as far north as the Lower Rio Grande Valley. The Common Pauraque is the tropical counterpart of the Eastern Whip-poor-will, a Neotropical migrant that nests in scattered forest locations throughout eastern North America.
I would note that we saw no “snowbirds”—long-term vacationers from the northern states and Canada who fill the park through the cooler months of fall, winter, and spring. They were gone for the summer. But for a few other friendly folks, we had the entire campground to ourselves for the duration of our stay.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY THREE—May 23, 1983
For Russ, Harold, and Steve, this trip would target several bird species each individual had never observed at any prior time in their lives. Upon seeing a new bird, they could add it to their personal “life list”. They, like thousands of other “listers”, were dedicated to the goal of having a life list that included over 600 species seen in the American Birding Association (A.B.A.) area—North America north of Mexico. Harold had traveled throughout much of North America (and the world) and had an A.B.A. life list well in excess of 600 species, thus he had seen nearly all of the regularly occurring birds in the coverage area. His chance for seeing new species was limited to vagrants that might wander into North America or tropical birds that, over time, had extended their range north of Mexico into the United States. I don’t recall how many species Russ and Steve had seen, but I know each had very few opportunities for new finds east of the Rocky Mountains. For all three of these men, the Lower Rio Grande Valley presented a best bet to add multiple species to their lists. I had never been south of Cape Hatteras or west of Pennsylvania, so I had the opportunity to add dozens of species to a life list. Throughout the trip, Russ, Harold, and Steve enthusiastically helped me locate and see new species. As a result, I saw over 50 new birds to add to my list.
One of the functions of the American Birding Association was to decide which bird species an observer could add to the life list. The official A.B.A. list was revised regularly to include not only regularly occurring native species, but vagrants as well. One of the trickier determinations was the status of introduced species. Back in 1983, a birder could count a Ring-necked Pheasant seen in Pennsylvania on their A.B.A. life list because they were thought to be freely reproducing with a population sustainably established in the state. Today, they are considered an exotic release and are not countable under A.B.A. rules.
Enter the Black Francolin (Francolinus francolinus), a member of the pheasant family that back in 1983, was countable under A.B.A. rules. Native to India, the Black Francolin was introduced into southwest Louisiana in 1961 and was apparently reproducing and established. Russ had a tip that they were seen with some regularity in areas of farmland, marsh, and oil fields south of Vinton, Louisiana. It was one of this trip’s target species for his life list.
“Ready for Black Francolin. Up at 5:30 — After breakfast, we went to Gum Cove Road. No Francolins, but at the end of the blacktop road, we had 5 Purple Gallinules in the scope at one time. King Rails were plentiful. We found a dead male Painted Bunting. Later, we saw a very beautiful live one. Water everywhere. Flooded fields everywhere. The road was flooded for about 50 yards at one point. White Ibis were abundant.”
Other sightings of note along Gum Cove Road included: Northern Bobwhite, Common Nighthawk, Cattle Egret, Green Heron, American Bittern, Snowy Egret, Glossy Ibis, Black-necked Stilt (Himantopus mexicanus), Forster’s Tern, Black Tern, Yellow-billed Cuckoo, Eastern Kingbird, Purple Martin, Barn Swallow, Brown Thrasher, Loggerhead Shrike, Red-winged Blackbird, Brown-headed Cowbird, Eastern Meadowlark, Boat-tailed Grackle (Quiscalus major), and Great-tailed Grackle (Quiscalus mexicanus)—a very large and noisy blackbird I had never seen before.
The reader may be interested to know that today, the area between Vinton and the Gulf of Mexico has largely been surrendered to the forces of the hurricanes that strike the region with some regularity. Cameron Parish* is a sparsely populated buffer zone of marshes, abundant wildlife, and oil and gas wells. Its population of more than 9,000 in 1983 has plunged to less than 6,000 today. Hurricane Rita (2005) and Hurricane Ike (2008) precipitated the sharp decline. The latter hurricane had a 22-foot storm surge that flooded areas 60 miles inland of the coastline. Following these storms, the majority of severely damaged and destroyed homes were not rebuilt and residents in the most affected areas relocated. In 2020, Hurricane Laura made landfall at Cameron Parish with record-tying 150 mph winds and a storm surge that pushed flood waters inland to Lake Charles. Six weeks later, Hurricane Delta followed with 100 mph winds. For government agencies, the emergency response required by these two storms was minimized by the reduced presence of people and/or their personal property.
* A parish in Louisiana is similar to a county in other states.
“After a quick stop at the camp grounds, where I slipped and fell in the shower last nite, we headed south. Larry saw many birds en route.”
Russ took a bad fall on a slippery wet concrete floor and had bruises to show for it. It worried me; he was 71 years old at the time. But he was adamant about continuing on and did so with great vigor.
Just hours after a sojourn through the swampy parcels south of Vinton, we were cruising through the metropolis of Houston, Texas, then across a landscape with less cultivated cropland and more scrubland with grazing. Here and there, but primarily to the east of Houston, blankets of roadside wildflowers painted the landscape with eye-popping color. Lady Bird Johnson encouraged the plantings soon after she and Lyndon returned to Texas upon leaving life in the White House in 1969. The sight of those vivid blooms was so memorable and so beautiful. One couldn’t resist making nasty comparisons to the gobs of mowed grass and mangled trash along the highways back in Pennsylvania.
Birds along the way: Ruby-throated Hummingbird, Common Nighthawk, Black-bellied Whistling Duck, Yellow-crowned Night Heron, Great Blue, Heron, Great Egret, Black Vulture, Turkey Vulture, Red-tailed Hawk, Laughing Gull, Black Tern, Scissor-tailed Flycatcher, Cliff Swallow, Loggerhead Shrike, and Painted Bunting. I saw my first Black-bellied Whistling Ducks (Dendrocygna autumnalis) and Golden-fronted Woodpecker (Melanerpes aurifrons) near Woodsboro, Texas, and added both to my life list.
“We stopped for the nite at an A OK camp ground 7 miles south of Kingsville.”
Birds at the camp included two Black-bellied Whistling Ducks flying overhead, Common Nighthawk, Golden-fronted Woodpecker, Blue Grosbeak, and another “lifer”—Curve-billed Thrasher (Toxostoma curvirostre).
We also saw a Mexican Ground Squirrel (Ictidomys mexicanus), easily identified by the rows of white spots running the length of its back.
While relaxing at the campsite that evening, we watched the landscape darken and remarked how interesting it was that the glowing red sun had yet to set below the distant horizon—a land so very flat and air so hazy and humid.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
The trip was scheduled to coincide with breeding season in order to provide a good chance of locating a number of tropical species that happen to reach the northern limit of their range along the Lower Rio Grande. In addition, there was the possibility of seeing many northbound end-of-season spring migrants funneling through the valley as they followed the Gulf Coast on their way to nesting grounds in eastern and central sections of the United States and Canada.
DAY ONE—May 21, 1983
The trip began at Russ Markert’s home in Lititz, Pennsylvania where I slept the night before departure. Markert’s van camper would be both our mode of transportation and accommodation for the journey. Upon arrival in south Texas, we would pick up Harold Morrin and Steve Santner at the Brownsville Airport. They would join us for a week before returning by air to Pennsylvania.
“Larry slept at my house last night so we could get an early start today — camper packed and read to go. Arose at 5:30. We alternated driving, about every two hours. Heavy rain through Virginia and West Virginia. Arrived at Sweetwater KOA, Tennessee, at 5:30 P.M. The weather turned to rain.”
Northern Bobwhite were among the many birds of farm and field at the Sweetwater KOA campground. After dinner and before the rain began, I recall going for a swim in the pool, something I craved being able to do during the sweltering evenings we would experience in south Texas during the week to follow.
If you’re like us, you’re forgoing this year’s egg hunt due to the prices, and, well, because you’re a little bit too old for such a thing.
Instead, we took a closer look at some of our wildlife photographs from earlier in the week. We’ve learned from experience that we don’t always see the finer details through the viewfinder, so it often pays to give each shot a second glance on a full-size screen. Here are a few of our images that contained some hidden surprises.
..but upon closer inspection we located…
..but after zooming in a little closer we found…
..but then, following further examination, we discovered…
Looks like I’m gonna be in the doghouse again—this time by way of the hen house. But why should I care? Here we go.
A few weeks ago, back when eggs were still selling for less than five dollars a dozen, the Pennsylvania Department of Agriculture renewed calls for owners and caretakers of outdoor flocks of domestic poultry (backyard chickens) to keep their birds indoors to protect them from the spread of bird flu—specifically “Highly Pathogenic Avian Influenza” (H.P.A.I.). At least one story edited and broadcast by a Susquehanna valley news outlet gave the impression that “vultures and hawks” are responsible for the spread of avian flu in chickens. To see if recent history supports such a deduction, let’s have a look at the U.S.D.A.’s Animal and Plant Health Inspection Service’s 2022-2023 list of the detection of Highly Pathogenic Avian Influenza in birds affected in counties of the Lower Susquehanna River Watershed in Pennsylvania.
H.P.A.I. 2022 Confirmed Detections as of January 13, 2023
This listing includes date of detection, county of collection, type/species of bird, and number of birds affected. WOAH (World Organization for Animal Health) birds include backyard poultry, game birds raised for eventual release, domestic pet species, etc.
12/30/2022 Adams Black Vulture
12/15/2022 Lancaster Canada Goose
12/15/2022 Lebanon Black Vulture
12/15/2022 Adams Black Vulture (3)
11/8/2022 Cumberland Black Vulture (4)
11/4/2022 Dauphin WOAH Non-Poultry (130)
10/19/2022 Dauphin Captive Wild Rhea (4)
10/17/2022 Adams Commercial Turkey (15,100)
10/11/2022 Adams WOAH Poultry (2,800)
9/30/2022 Lancaster Mallard
9/30/2022 Lancaster Mallard
9/29/2022 Lancaster WOAH Non-Poultry (180)
9/29/2022 York Commercial Turkey (25,900)
8/24/2022 Dauphin Captive Wild Crane
7/15/2022 Lancaster Great Horned Owl
7/15/2022 York Bald Eagle
7/15/2022 Dauphin Bald Eagle
6/16/2022 Dauphin Black Vulture
6/16/2022 Dauphin Black Vulture (4)
5/31/2022 Lancaster Black Vulture (2)
5/31/2022 Lancaster Black Vulture
5/10/2022-Lncstr-Commercial Egg Layer (72,300)
4/29/2022-Lncstr-Commercial Duck (19,300)
4/27/2022-Lncstr-Commercial Broiler (18,100)
4/26/2022-Lncstr-Commercial Egg Layer (307,400)
4/22/2022-Lncstr-Commercial Broiler (50,300)
4/20/2022-Lncstr-Commercial Egg Layer (1,127,700)
4/20/2022-Lncstr-Commercial Egg Layer (879,400)
4/15/2022-Lncstr-Commercial Egg Layer (1,380,500)
In the Lower Susquehanna River Watershed, it’s pretty obvious that the outbreak of avian flu got its foothold inside some of the area’s big commercial poultry houses. Common sense tells us that hawks, vultures, and other birds didn’t migrate north into the Lower Susquehanna River Watershed carrying bird flu, then kick in the doors of the enclosed hen houses to infect the flocks of chickens therein. Anyone paying attention during these past three years knows that isolation and quarantine are practices more easily proposed than sustained. Human footprints are all over the introduction of this infection into these enormous flocks. Simply put, men don’t wipe their feet when no one is watching! The outbreak of bird flu in these large operations was brought under control quickly, but not until teams of state and federal experts arrived to assure proper sanitary and isolation practices were being implemented and used religiously to prevent contaminated equipment, clothing, vehicles, feed deliveries, and feet from transporting virus to unaffected facilities. Large poultry houses aren’t ideal enclosures with absolute capabilities for excluding or containing viruses and other pathogens. Exhaust systems often blow feathers and waste particulates into the air surrounding these sites and present the opportunity for flu to be transported by wind or service vehicles and other conveyances that pass through contaminated ground then move on to other sites—both commercial and non-commercial. Waste material and birds (both dead and alive) removed from commercial poultry buildings can spread contamination during transport and after deposition. The sheer volume of the potentially infected organic material involved in these large poultry operations makes absolute containment of an outbreak nearly impossible.
Looking at the timeline created by the list of U.S.D.A. detections, the opportunity for bird flu to leave the commercial poultry loop probably happened when wild birds gained access to stored or disposed waste and dead animals from an infected commercial poultry operation. For decades now, many poultry operations have dumped dead birds outside their buildings where they are consumed by carrion-eating mammals, crows, vultures, Bald Eagles, and Red-tailed Hawks. For these species, discarded livestock is one of the few remaining food sources in portions of the Lower Susquehanna River Watershed where high-intensity farming has eliminated other forms of sustenance. They will travel many miles and gather in unnatural concentrations to feast on these handouts—creating ideal circumstances for the spread of disease.
The sequence of events indicated by the U.S.D.A. list would lead us to infer that vultures and Bald Eagles were quick to find and consume dead birds infected with H5N1—either wild species such as waterfowl or more likely domestic poultry from commercial operations or from infectious backyard flocks that went undetected. As the report shows, Black Vultures in particular seem to be susceptible to morbidity. Their frequent occurrence as victims highlights the need to dispose of potentially infectious poultry carcasses properly—allowing no access for hungry wildlife including scavengers.
The positive test on a Great Horned Owl is an interesting case. While the owl may have consumed an infected wild bird such as a crow, there is the possibility that it consumed or contacted a mammalian scavenger that was carrying the virus. Aside from rodents and other small mammals, Great Horned Owls also prey upon Striped Skunks with some regularity. Most of the dead poultry from flu-infected commercial flocks was buried onsite in rows of above-ground mounds. Skunks sniff the ground for subterranean fare, digging up invertebrates and other food. Buried chickens at a flu disposal site would constitute a feast for these opportunistic foragers. A skunk would have no trouble at all finding at least a few edible scraps at such a site. Then a Great Horned Owl could easily seize and feed upon such a flu virus-contaminated skunk.
BACKYARD POULTRY
Before we proceed, the reader must understand the seldom-stated and never advertised mission of the Pennsylvania Department of Agriculture—to protect the state’s agriculture industry. That’s it; that’s the bottom line. Regulation and enforcement of matters under the purview of the agency have their roots in this goal. While they may also protect the public health, animal health, and other niceties, the underlying purpose of their existence in its current manifestation is to protect the agriculture industry(s) as a whole.
This is not a trait unique to the Pennsylvania Department of Agriculture. It is at the core of many other federal and state agencies as well. Following the publication of Upton Sinclair’s The Jungle in 1906, a novel decrying “wage slavery” in the meat packing industry, the federal government took action, not for the purpose of improving the working conditions for labor, but to address the unsanitary food-handling practices described in the book by creating an inspection program to restore consumer confidence in the commercially-processed meat supply so that the industry would not crumble.
Locally, few things make the dairy industry and the Pennsylvania Department of Agriculture more nervous than small producers selling “raw milk”. In the days before pasteurization and refrigeration, people were frequently sickened and some even died from drinking bacteria-contaminated “raw milk”. In Pennsylvania, the production and sale of dairy products including “raw milk” is closely regulated and requires a permit. Retention of a permit requires submitting to inspections and passing periodic herd and product testing. Despite the dangers, many consumers continue to buy “raw milk” from farms without permits. These sales are like a ticking time bomb. The bad publicity from an outbreak of food-borne illness traced back to a dairy product—even if it originated in an “outlaw” operation—could decimate sales throughout the industry. Because just one sloppy farm selling “raw milk” could instantly erode consumer confidence and cause an industry-wide collapse of the market resulting in a loss of millions of dollars in sales, it is a deeply concerning issue.
Enter the backyard chicken—a two-fold source of anxiety for the poultry industry and its regulators. Like unregulated meat and dairy products, eggs and meat from backyard poultry flocks are often marketed without being monitored for the pathogens responsible for the transmission of food-borne illness. From the viewpoint of the poultry industry, this situation poses a human health risk that in the event of an outbreak, could erode consumer confidence, not only in homegrown organic and free-range products, but in the commercial line of products as well. Consumers can be very reactive upon hearing news of an outbreak, recalling few details other than “the fowl is foul”— then refraining from buying poultry products. The second and currently most concerning source of trepidation among members of the poultry industry though is the threat of avian flu and other diseases being harbored in and transmitted via flocks of backyard birds.
The Green Revolution, the post-World War II initiative that integrated technology into agriculture to increase yields and assure an adequate food supply for the growing global population, brought changes to the way farmers raised poultry for market. Small-scale poultry husbandry slowly disappeared from many farms. Instead, commercial operations concentrated birds into progressively-larger indoor flocks to provide economy of scale. Over time, genetics and nutrition science have provided the American consumer with a line of readily available high-quality poultry products at an inexpensive price. Within these large-scale operations, poultry health is closely monitored. Though these enclosures may house hundreds of thousands of birds, the strategy during an outbreak of communicable disease is to contain an outbreak to the flock therein, writing it off so to speak to prevent the pathogens from finding their way into the remainder of the population in a geographic area, thus saving the industry at the expense of the contents of a single operation. Adherence to effective biosecurity practices can contain outbreaks in this way.
The renewed popularity of backyard poultry is a reversal of the decades-long trend towards reliance on ever-larger indoor operations for the production of birds and eggs. But backyard flocks may make less-than-ideal neighbors for commercial operations, particularly when birds are left to roam outdoors. Visitors to properties with roaming chickens, ducks, geese, and turkeys may pick up contamination on their shoes, clothing, tires, and equipment, then transmit the pathogenic material to flocks at other sites they visit without ever knowing it. Even the letter carrier can carry virus from a mud puddle on an infected farm to a grazing area on a previously unaffected one. Unlike commercial operations, hobby farms frequently buy, sell, and trade livestock and eggs without regard to disease transmission. The rate of infection in these operations is always something of a mystery. No state or county permits are required for keeping small numbers of poultry and outbreaks like avian flu are seldom reported by caretakers of flocks of home-raised birds, though their occurrence among them may be widespread. The potential for pathogens like avian flu virus circulating long-term among flocks of backyard poultry in close proximity to commercial houses is a real threat to the industry.
There are a variety of motivations for tending backyard poultry. While for some it is merely a form of pet keeping, others are more serious about the practice—raising and breeding exotic varieties for show and trade. Increasingly, backyard flocks are being established by people seeking to provide their own source of eggs or meat. For those with larger home operations, supplemental income is derived from selling their surplus poultry products. Many of these backyard enthusiasts are part of a movement founded on the belief that, in comparison to commercially reared birds, their poultry is raised under healthier and more humane conditions by roaming outdoors. Organic operators believe their eggs and meat are safer for consumption—produced without the use of chemicals. For the movement’s most dedicated “true believers”, the big poultry industry is the antagonist and homegrown fowl is the only hope. It’s similar to the perspective members of the “raw milk” movement have toward pasteurized milk. True believers are often willing to risk their health and well-being for the sake of the cause, so questioning the validity of their movement can render a skeptic persona non grata.
For the consumer, the question arises, “Are eggs and poultry from the small-scale operations better?”
While many health-conscious animal-friendly consumers would agree to support the small producer from the local farm ahead of big business, the reality of supplying food for the masses requires the economy of scale. The billions of people in the world can’t be fed using small-scale and/or organic growing methods. The Green Revolution has provided record-high yields by incorporating herbicides, insecticides, plastic, and genetic modification into agriculture. To protect livestock and improve productivity, enormous indoor operations are increasingly common. Current economics tell the story—organic production can’t keep up with demand, that’s why the prices for items labelled organic are so much higher.
To the consumer, buying poultry raised outdoors is an appealing option. Compared to livestock crowded into buildings, they feel good about choosing products from small operations where birds roam free and happy in the sunshine.
But is the quality really better? Some research indicates not. Salmonella outbreaks have been traced back to poultry meat sourced from small unregulated operations. Studies have found dioxins in eggs produced by hens left to forage outdoors. The common practice of burning trash can generate a quantity of ash sufficient to contaminate soils with dioxins, chemical compounds which persist in the environment and in the fatty tissue of animals for years. The presence of elevated levels of dioxins in eggs from outdoor grazing operations may pose a potential consumer confidence liability for the entire egg industry.
Birds raised or kept in an outdoor zoo or backyard poultry setting can be susceptible to viruses and other pathogens when wild birds including vultures and hawks become attracted to the captives’ food and water when it is placed in an accessible location. In addition, hunting and scavenging birds are opportunistic— attracted to potential food animals when they perceive vulnerability. Selective breeding under domestication has rendered food poultry fat, dumb, and too genetically impaired for survival in the wild. These weaknesses instantly arouse the curiosity of raptors and other predators whose function in the food web is to maintain a healthy population of animals at lower tiers of the food chain by selectively consuming the sickly and weak. In settings such as those created by high-intensity agriculture and urbanization, wild birds may find the potential food sources offered by outdoor zoos and backyard poultry irresistible. As a result they may perch, loaf, and linger around these locations—potentially exposing the captive birds to their droppings and transmission of bird flu and other diseases.
While outdoor poultry operations usually raise far fewer birds than their commercial counterparts, their animals are still kept in densities high enough to promote the rapid spread of microbiological diseases. Clusters of outdoor flocks can become a reservoir of pathogens with the capability of repeatedly circulating disease into populations of wild birds and even into commercial poultry operations—threatening the industry and food supply for millions of people. For this reason, state and federal agencies are encouraging operators to keep backyard poultry indoors—segregated from natural and anthropogenic disease vectors and conveyances that might otherwise visit and interact with the flock.
BACK TO THE FUTURE?—NOT LIKELY
The hobby farmer, the homesteader, the pet keeper, and the consumer seldom realize what the modern farmer is coming to know—domestic livestock must be segregated from the sources of contamination and disease that occur outdoors. Adherence to this simple concept helps assure improved health for the animals and a safer food supply for consumers. In the future, outdoor production of domestic animals, particularly those used as a food supply, is likely to be classified as an outdated and antiquated form of animal husbandry.
THE THREAT FROM PRIONS
If there are three things the world learned from the SARS CoV-2 (Covid-19) epidemic, it’s that 1) eating or handling bush meat can bring unwanted surprises, 2) dense populations of very mobile humans are ideal mediums for uncontrolled transmission of disease, and 3) quarantine is easier said than done.
If you think viruses are bad, you don’t even want to know about prions. Prions are a prime example of why now is a good time to begin housing domestic animals, including pets, indoors to segregate them from wildlife. And prions are a good example of why we really ought to think twice about relying on wild animals as a source of food. Prions may make us completely rethink the way we interact with animals of any kind—but we had better do our thinking fast because prions turn the brains of their victims into Swiss cheese.
Diseases caused by prions are rapidly progressing neurodegenerative disorders for which there is no cure. Prions are an abnormal isoform of a cellular glycoprotein. They are currently rare, but prions, because they are not living entities, possess the ability to begin accumulating in the environment. They not only remain in detritus left behind by the decaying carcasses of afflicted animals, but can also be shed in manure—entering soils and becoming more and more prevalent over time. Some are speculating that they could wind up being man’s downfall.
The Centers for Disease Control lists these human afflictions caused by prions…
Schoeters, Greet, and Ron Hoogenboom. 2006. Contamination of Free-range Chicken Eggs with Dioxins and Dioxin-like Polychlorinated Biphenyls. Molecular Nutrition and Food Research. (10):908-14.
Szczepan, Mikolajczyk, Marek Pajurek, Malgorzata Warenik-Bany, and Sebastian Maszewski. 2021. Environmental Contamination of Free-range Hen with Dioxin. Journal of Veterinary Research. 65(2):225-229.
U.S.D.A. Animal and Plant Inspection Service. 2022 Confirmations of Highly Pathogenic Avian Influenza. aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/avian/avian-influenza/hpai-2022/2022-hpai-commercial-backyard-flocks as accessed January 14, 2023.
U.S.D.A. Animal and Plant Inspection Service. 2022 Confirmations of Highly Pathogenic Avian Influenza. aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/avian/avian-influenza/hpai-2022/2022-hpai-wild-birds as accessed January 14, 2023.
With the gasoline and gunpowder gang’s biggest holiday of the year now upon us, wouldn’t it be nice to get away from the noise and the enduring adolescence for just a little while to see something spectacular that isn’t exploding or on fire? Well, here’s a suggestion: head for the hills to check out the flowers of our native rhododendron, the Great Rhododendron (Rhododendronmaximum), also known as Rosebay.
Thickets composed of our native heathers/heaths (Ericaceae) including Great Rhododendron, Mountain Laurel, and Pinxter Flower (Rhododendron periclymenoides), particularly when growing in association with Eastern Hemlock and/or Eastern White Pine, provide critical winter shelter for forest wildlife. The flowers of native heathers/heaths attract bees and other pollinating insects and those of the deciduous Pinxter Flower, which blooms in May, are a favorite of butterflies and Ruby-throated Hummingbirds.
Forests with understories that include Great Rhododendrons do not respond well to logging. Although many Great Rhododendrons regenerate after cutting, the loss of consistent moisture levels in the soil due to the absence of a forest canopy during the sunny summertime can, over time, decimate an entire population of plants. In addition, few rhododendrons are produced by seed, even under optimal conditions. Great Rhododendron seeds and seedlings are very sensitive to the physical composition of forest substrate and its moisture content during both germination and growth. A lack of humus, the damp organic matter in soil, nullifies the chances of successful recolonization of a rhododendron understory by seed. In locations where moisture levels are adequate for their survival and regeneration after logging, impenetrable Great Rhododendron thickets will sometimes come to dominate a site. These monocultures can, at least in the short term, cause problems for foresters by interrupting the cycle of succession and excluding the reestablishment of native trees. In the case of forests harboring stands of Great Rhododendron, it can take a long time for a balanced ecological state to return following a disturbance as significant as logging.
In the lower Susquehanna region, the Great Rhododendron blooms from late June through the middle of July, much later than the ornamental rhododendrons and azaleas found in our gardens. Set against a backdrop of deep green foliage, the enormous clusters of white flowers are hard to miss.
In the Lower Susquehanna River Watershed, there are but a few remaining stands of Great Rhododendron. One of the most extensive populations is in the Ridge and Valley Province on the north side of Second Mountain along Swatara Creek near Ravine (just off Interstate 81) in Schuylkill County, Pennsylvania. Smaller groves are found in the Piedmont Province in the resort town of Mount Gretna in Lebanon County and in stream ravines along the lower river gorge at the Lancaster Conservancy’s Ferncliff and Wissler’s Run Preserves. Go have a look. You’ll be glad you did.
It’s surprising how many millions of people travel the busy coastal routes of Delaware each year to leave the traffic congestion and hectic life of the northeast corridor behind to visit congested hectic shore towns like Rehobeth Beach, Bethany Beach, and Ocean City, Maryland. They call it a vacation, or a holiday, or a weekend, and it’s exhausting. What’s amazing is how many of them drive right by a breathtaking national treasure located along Delaware Bay just east of the city of Dover—and never know it. A short detour on your route will take you there. It’s Bombay Hook National Wildlife Refuge, a quiet but spectacular place that draws few crowds of tourists, but lots of birds and other wildlife.
Let’s join Uncle Tyler Dyer and have a look around Bombay Hook. He’s got his duck stamp and he’s ready to go.
Remember to go the Post Office and get your duck stamp. You’ll be supporting habitat acquisition and improvements for the wildlife we cherish. And if you get the chance, visit a National Wildlife Refuge. November can be a great time to go, it’s bug-free! Just take along your warmest clothing and plan to spend the day. You won’t regret it.
Yesterday, a hike through a peaceful ridgetop woods in the Furnace Hills of southern Lebanon County resulted in an interesting discovery. It was extraordinarily quiet for a mid-April afternoon. Bird life was sparse—just a pair of nesting White-breasted Nuthatches and a drumming Hairy Woodpecker. A few deer scurried down the hillside. There was little else to see or hear. But if one were to have a look below the forest floor, they’d find out where the action is.
2021 is an emergence year for Brood X, the “Great Eastern Brood”—the largest of the 15 surviving broods of Periodical Cicadas. After seventeen years as subterranean larvae, the nymphs are presently positioned just below ground level, and they’re ready to see sunlight. After tunneling upward from the deciduous tree roots from which they fed on small amounts of sap since 2004, they’re awaiting a steady ground temperature of about 64 degrees Fahrenheit before surfacing to climb a tree, shrub, or other object and undergo one last molt into an imago—a flying adult.
The woodlots of the Lower Susquehanna River Watershed won’t be quiet for long. Loud choruses of male Periodical Cicadas will soon roar through forest and verdant suburbia. They’re looking for love, and they’re gonna die trying to find it. And dozens and dozens of animal species will take advantage of the swarms to feed themselves and their young. Yep, the woods are gonna be a lively place real soon.
It’s just common sense to take it easy and drive carefully when snow covers streets and highways. Everyone knows that. But did you know that slowing down when the landscape is blanketed in white can save lives even after the roadways have been cleared?
Following significant snowfalls such as the one earlier this week, birds and other wildlife are attracted to bare ground along the edges of plowed pavement. They are often so preoccupied with the search for food that they ignore approaching cars and trucks until it is too late.
Take a look at the species found today along a one mile stretch of plowed rural roadway in the lower Susquehanna valley.
For many species of wildlife in the Lower Susquehanna River Watershed, the fragmented and impaired state of habitat already challenges their chances of surviving the winter. Snow cover can isolate them from their limited food supplies and force them to roadsides and other dangerous locations to forage. Mauling them with motor vehicles just adds to the escalating tragedy, so do wildlife and yourself a favor—please slow down.
You need to get outside and go for a walk. You’ll be sorry if you don’t. It’s prime time to see wildlife in all its glory. The songs and colors of spring are upon us!
If you’re not up to a walk and you just want to go for a slow drive, why not take a trip to Middle Creek Wildlife Management Area and visit the managed grasslands on the north side of the refuge. To those of us over fifty, it’s a reminder of how Susquehanna valley farmlands were before the advent of high-intensity agriculture. Take a look at the birds found there right now.
And remember, if you happen to own land and aren’t growing crops on it, put it to good use. Mow less, live more. Mow less, more lives.
Local birders enjoy going to the Atlantic coast of New Jersey and Delmarva in the winter. The towns and beaches host far fewer people than birds, and many of the species seen are unlikely to be found anywhere else in the region. Unusual rarities add to the excitement.
The regular seaside attraction in winter is the variety of diving ducks and similar water birds that feed in the ocean surf and in the saltwater bays. Most of these birds breed in Canada and many stealthily cross over the landmass of the northeastern United States during their migrations. If an inland birder wants to see these coastal specialties, a trip to the shore in winter or a much longer journey to Canada in the summer is normally necessary—unless there is a fallout.
Migrating birds can show up in strange places when a storm interrupts their flight. Forest songbirds like thrushes and warblers frequently take temporary refuge in a wooded backyard or even in a city park when forced down by inclement weather. Loons have been found in shopping center parking lots after mistaking the wet asphalt for a lake. Fortunately though, loons, ducks, and other water birds usually find suitable ponds, lakes, and rivers as places of refuge when forced down. For inland birders, a fallout like this can provide an opportunity to observe these coastal species close to home.
Not so coincidentally, it has rained throughout much of today in the Lower Susquehanna River Watershed, apparently interrupting a large movement of migrating birds. There is, at the time of this writing, a significant fallout of coastal water birds here. Hundreds of diving ducks and other benthic feeders are on the Susquehanna River and on some of the clearer lakes and ponds in the region. They can be expected to remain until the storm passes and visibility improves—then they’ll promptly commence their exodus.
The following photographs were taken during today’s late afternoon thundershower at Memorial Lake State Park at Fort Indiantown Gap, Lebanon County.
Migrating land birds have also been forced down by the persistent rains.
Why not get out and take a slow quiet walk on a rainy day. It may be the best time of all for viewing certain birds and other wildlife.
Many are wont to say that they have no capacity for scientific pursuits, and having no capacity, they consequently have no love for them. I do not believe, that as a general thing, a love for science is necessarily innate in any man. It is the subject of cultivation and is therefore acquired. There are doubtless many, whose love for these and kindred pursuits is hereditary, through the mental biases and preoccupations of their progenitors, but in the masses of mankind it is quite otherwise. In this consists its redeeming qualities, for I do not think the truly scientific mind can either be an idle, a disorderly, or a very wicked one. There may be scientific men, who, forgetful of its teachings, are imperious and ambitious–who may have foregone their fealty to their country and their God, but as a general thing they are humble, social and law-abiding. If, therefore, there is a human being who desires to break off from old and evil associations, and form new and more virtuous ones, I would advise him to turn his attention to some scientific specialty, for the cultivation of a new affection, if there are no other and higher influences more accessible. In this pursuit he will, in time, be enabled to supplant the old and heartfelt affection. The occupation of his mind in the pursuit of scientific lore will wean him from vicious, trivial, and unmanly pursuits, and point out to him a way that is pleasant and instructive to walk in, which will ultimately lead to moral and intellectual usefulness. I wish I was accessible to them, and possessed the ability to impress this truth with sufficient emphasis upon the minds of the rising generation. This fact, that in all moral reformations, a love for the opposite of any besetting evil must be cultivated, before that evil can be surely eradicated, has been too much overlooked and too little valued in moral ethics. But true progress in this direction implies that, under all circumstances, men should “act in freedom according to reason.”
-Simon S. Rathvon
In the cellar of the North Museum on the campus of Franklin and Marshall College in Lancaster, Pennsylvania, is an assemblage of natural history specimens of great antiquity. The core of the collection has its origins in the endeavors of a group of mid-to-late nineteenth-century naturalists whose diligence provided a most thorough study of the plants and animals found within what was at the time America’s most productive farming county.
The members of the Linnaean Society of Lancaster City and County shared a passion for collecting, identifying, classifying, and documenting the flora and fauna of the region. Some members were formally educated and earned a living in the field of science, but the majority were in the process of self-education and balanced their natural history occupation with an unrelated means to provide financially for their families. The latter benefited greatly from their associations with the former, gaining expertise and knowledge while participating in the functions of the group.
On February 24, 1866, Simon S. Rathvon, the society’s Treasurer, read an essay in commemoration of the group’s fourth anniversary. Rathvon earned a living as a tailor, first in Marietta, a thriving river town at the time, then in Lancaster City. In 1840, Rathvon was elected into the Marietta Natural History Lyceum where, as a collections curator, he became associated with principals Judge John J. Libhart, an amateur ornithologist, and Samuel S. Haldeman, a geologist and soon to be widely-known malacologist. Haldeman, in 1842, upon noticing the new member’s interest in beetles and other insects, provided books, guidance, and inspiration, thus intensifying Rathvon’s study of entomology. Rathvon’s steadfast dedication eventually led to his numerous achievements in the field which included the publication of over 30 papers, many on the topic of agricultural entomology. Rathvon’s scientific understanding of insect identification and taxonomy was a foundation for his practical entomology, which moved beyond mere insect collection to focus upon the study of the life histories of insects, particularly the good and bad things they do. He then applied that knowledge to help growers solve pest problems, often stressing the value of beneficial species for maintaining a balance in nature. From 1869 through 1884, Rathvon edited and published Lancaster Farmer, a monthly (quarterly from 1874) agricultural journal in which he educated patrons with his articles on “economic entomology”. Rathvon continued earning a living in the tailor business, seemingly frustrated that his financially prudent advice on insect control in Lancaster Farmer failed to entice more would-be readers to part with the one dollar annual subscription fee. For many years, Rathvon crafted articles for local newspapers and wrote reports for the United States Department of Agriculture. In recognition of his achievements, Simon Rathvon received an honorary Ph.D. from Franklin and Marshall College in 1878.
In Rathvon’s anniversary essay, he details the origins of the Linnaean Society as a natural science committee within the “Lancaster Historical, Mechanical, and Horticultural Society” founded in 1853. The members of the committee, not finding sufficient support within the parent organization for their desired mission, “the cultivation and investigation of the natural history of Lancaster County…”, sought to form an independent natural history society. In February of 1862, the “Linnaean Society of Lancaster City and County” was founded to fulfill these ambitions.
Above all else, the written works by the members of the Linnaean Society and their predecessors have provided us with detailed accounts of the plants and animals found in Lancaster County, and in the lower Susquehanna River valley, using scientific binomial nomenclature, a genus and species name, as opposed to the variable folk and common names which, when used exclusively, often confuse or mislead readers. Consider the number of common names a species could have if just one was assigned by each of the languages of the world. Binomial nomenclature assigns one designation, a genus name and species name, in Latin, to each life-form (such as Homo sapiens for Humans), and it is adopted universally.
Rathvon would say of the naming of the Linnaean Society:
“…the name which the Society has adopted is in honorable commemoration of LINNAEUS, the great Swedish naturalist—one who may be justly regarded as a father in Natural Science. To him belongs the honor of having first promulgated the “binomial system of nomenclature,” a system that has done more to simplify the study of natural science than any light that has been brought to the subject by any man in any age.”
Carl Linnaeus lived from 1707 to 1778, and published his first edition of Systema Naturae in 1735.
The names of a number of the members and corresponding members on the Linnaean Society of Lancaster City and County’s rolls remain familiar. John P. McCaskey (educator) served as Corresponding Secretary. Doctor Abram P. Garber was a prominent Lancaster botanist and society member. Professor Samuel S. Haldeman (naturalist, geologist, and philologist), Professor J. L. LeConte (entomologist), Judge John J. Libhart, Professor Asa Gray (botanist), and the foremost legal egalitarian in the United States House of Representatives, the Honorable Thaddeus Stevens, were listed among the roster of corresponding members.
By the end of its fourth year, Rathvon enumerated the specimens in the collections of the society to exceed 32,000. These included all the species of mosses and plants known in the county, 200 bird specimens, an enormous insect collection with nearly 12,000 Coleoptera (Beetles), and more than 1,400 mollusk shells. The work of the society had already provided a thorough baseline of the flora and fauna of the lower Susquehanna River valley and Lancaster County.
Rathvon would continue as Treasurer and primary curator through the group’s first twenty-five years, their most active. By 1887, their library contained over 1,000 volumes, they possessed over 40,000 specimens, and more than 600 scientific papers had been read at their meetings.
Many of the society’s specimens were moved to the custody of Franklin and Marshall College following the group’s dissolution. In 1953, the collection found a home on the F&M campus at the newly constructed North Museum, named for benefactor Hugh M. North, where many of the specimens, particularly the birds, are on prominent display.
Among the mounted specimens in the North Museum collection is a Heath Hen, once a numerous coastal plain bird which was also of limited abundance in the Piedmont Province areas of southeast Pennsylvania prior to its rapid decline during the first half of the nineteenth century. In southern Lancaster County, the burned grasslands of the serpentine barrens in Fulton Township may have provided suitable Heath Hen habitat prior to the bird’s demise. Curiously, Judge John J. Libhart did not note the Heath Hen in his enumeration of the birds of Lancaster County in either 1844 or 1869, indicating it was seriously imperiled or may have already been extirpated.
The Heath Hen was extirpated from its entire Atlantic Coastal Plain mainland range by the mid-1860s. The last remaining population was restricted to Martha’s Vineyard where, for the first time, a conservation effort was initiated to try to save a species. After some promising rebounds, the Heath Hen’s recovery failed for a variety of reasons including: the population’s isolation on an island, severe winter storms, feral cat predation, and a flawed understanding of methods for conducting mosaic burns to maintain the bird’s scrub habitat and prevent large catastrophic fires. A large fire in 1906 reduced the island population to just 80 birds, then there was a strong rebound to an estimated 2,000 birds (800 counted) by April, 1916. One month later, a fire burned twenty percent of Martha’s Vineyard, striking while females were on the nest, and leaving mostly males as survivors. A downward spiral in numbers followed for another decade. Finally, from 1929 until his death in 1932, “Booming Ben”, the last Heath Hen, searched the island every spring for a mate that wasn’t there.
Based on life history and the morphology of specimens, the Heath Hen has long been considered to be a subspecies of the Greater Prairie Chicken (Tympanuchus cupido pinnatus), a bird of the tallgrass prairies. However, for more than a decade now, modern DNA analysis has kept taxonomists busy reclassifying and reworking the “tree of life”. For certain species, genetic discoveries often disqualify the long-trusted practice of determining a binomial name based on the visual appearance of specimens. Molecular study is making Linnaean classification more scientific, and is gradually untangling a web of names that man has been weaving for 200 years, often with scant evidence, in an effort to better understand the world around him. In the case of the Heath Hen, DNA research has thus far failed to conclusively determine its relationship to other species of prairie chickens. The lack of a sufficient pool of genetic material, particularly from mainland Heath Hens, reduces the ability of researchers to draw conclusions on this group of birds. There remains the possibility that the Heath Hen was genetically distinct from the Greater Prairie Chickens of the mid-western United States. This would be bad news for organizations studying the possibility of introducing the latter into the former’s historic range as a restoration program.
The last Carolina Parakeet (the only parrot species native to the eastern United States) died in captivity in the Cincinnati Zoo on February 21, 1918, one hundred years ago this past week. It was a species inhabiting primarily the lowland forests of the southeastern United States
In Lancaster County, Judge John J. Libhart wrote of the species in 1869, “…Carolina Parrot, Accidental; a flock seen near Manheim by Mr. G. W. Hensel.” Libhart did not mention the species in his earlier ornithological writings (1844). Therefore, the Hensel sighting probably occurred sometime between 1844 and 1869. The fate of a specimen reported to have been collected in the town of Willow Street sometime during the nineteenth century is unknown, the written details lack the date of its origin and other particulars that may clarify the authenticity of the sighting.
McKinley (1979) researched numerous historical sight records of Carolina Parakeets, but found no specimen from Lancaster County, or from Pennsylvania, New Jersey, Delaware, the District of Columbia, or Maryland to substantiate any of the reports in the Mid-Atlantic states. In the days prior to high-speed photography, verification and documentation of the presence of an animal species relied on what seems today to be a brutal and excessive method of nature study, killing. Lacking a specimen, the historical status of Carolina Parakeets in Pennsylvania, an area often considered to be within the bird’s former range, may be considered by many authorities to be hypothetical.
The Passenger Pigeon, too, has been extinct for more than a century. In Lancaster County, Judge John J. Libhart listed the Passenger Pigeon by the common name “Wild Pigeon” and wrote of the species in 1869, “Migratory; spring and autumn; feeds on grain, oak and beach, mostly on berries; stragglers sometimes remain and breed in the county.” There are numerous accounts of their precipitous decline both locally and throughout their former range, each illustrating the tragic loss of another portion of the North American natural legacy.
Martha, the last surviving Passenger Pigeon, died on September 1, 1914, in the Cincinnati Zoo. Ironically, the last Carolina Parakeet would die in the same enclosure just three-and-one-half years later. In the wild, the final three records of Passenger Pigeons were all of birds that were shot for taxidermy mounts in 1900, 1901, and 1902—an embarrassing human legacy.
By the early twentieth century, concerned citizens were beginning to realize the danger posed to many species of flora and fauna by man’s activities. In the eastern United States, the vast forests had been logged, the wetlands drained, and the streams and rivers dammed. Nearly all of the landscape had been altered in some way. Animals were harvested with little concern for the sustenance of their populations. Nearly unnoticed, the seemingly endless abundance and diversity of wildlife found in the early days of European colonization had dwindled critically.
The movement to conserve and protect threatened species from relentless persecution owes its start to the Linnaean taxonomists, the specimen collectors who gave uniformly recognizable names to nearly all of North America’s plants and animals. Significant too were John James Audubon and many others who used specimens as models to create accurate artwork which allowed scientists and citizens alike to learn to identify and name the living things they were seeing and, as time went by, not seeing.
Binomial nomenclature enabled the new conservationists to communicate accurately, reducing misunderstandings resulting from the use of many different names for one species or a shared name for multiple species. Discussions on the status of Columba migratorius (the binomial name for Passenger Pigeon in the nineteenth century) could occur without using the confusing local names for the Passenger Pigeon such as Wood Pigeon or, here in Pennsylvania, Wild Pigeon, a term which could describe any number of free-ranging pigeon or dove species. A binomial name, genus and species, makes the identity of a particular plant or animal, for lack of a more fitting term, specific.
Appreciation for the work completed by taxonomists who killed thousands of animals so each could be classified and assigned a name particular to its lineage is what finally motivated some to seek a cessation of the unchecked catastrophic killing of living things. It’s the paradox of late nineteenth-century conservation. The combined realization that a species is unique among other life-forms and that continuing to kill it for specimens, “style”, “sport”, or just an adrenaline thrill could eliminate it forever became an intolerable revelation. The blood would be on the hands of an audacious mankind, and it was unthinkable. Something had to be done. Unfortunately for the Passenger Pigeon, the Carolina Parakeet, and the Heath Hen, help came too late.
SOURCES
Greenburg, Joel. 2014. A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction. Bloomsbury Publishing. New York.
Libhart, John J. 1844. “Birds of Lancaster County”. I. Daniel Rupp’s History of Lancaster County. Gilbert Hills. Lancaster, PA.
Libhart, John J. 1869. “Ornithology”. J. I. Mombert’s An Authentic History of Lancaster County. J. E. Barr and Company. Lancaster, PA.
McKinley, Daniel. 1979. “History of the Carolina Parakeet in Pennsylvania, New Jersey, Delaware, Maryland, and the District of Columbia”. Maryland Birdlife. 35(1):1-10.
Palkovacs, Eric P.; Oppenheimer, Adam J.; Gladyshev, Eugene; Toepfer, John E.; Amato, George; Chase, Thomas; Caccone, Adalgesia. 2004. “Genetic Evaluation of a Proposed Introduction: The Case of the Greater Prairie Chicken and the Extinct Heath Hen”. Molecular Ecology. 13(7):1759-1769.
Rathvon, S. S. 1866. An Essay on the Origin of the Linnaean Society of Lancaster City and County, Its Objects and Progress. Pearsol and Geist. Lancaster, Pennsylvania.
Wheeler, Alfred G., Jr. and Miller, Gary L. 2006. “Simon Snyder Rathvon: Popularizer of Agricultural Entomology in Mid-19th Century America”. American Entomologist. 52(1):36-47.
Winpenny, Thomas R. 1990. “The Triumphs and Anguish of a Self-Made Man: 19th Century Naturalist S. S. Rathvon”. Pennsylvania History. 57(2):136-149.