LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED
A Natural History of Conewago Falls—The Waters of Three Mile Island
As week-old snow and ice slowly disappears from the Lower Susquehanna River Watershed landscape, we ventured out to see what might be lurking in the dense clouds of fog that for more than two days now have accompanied a mid-winter warm spell.
If scenes of a January thaw begin to awaken your hopes and aspirations for all things spring, then you’ll appreciate this pair of closing photographs…
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.
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.
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.
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.
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.
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…
The Centers for Disease Control lists these prion-caused ailments of other animals…
SOURCES
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.
Despite being located in an urbanized downtown setting, blustery weather in recent days has inspired a wonderful variety of small birds to visit the garden here at the susquehannawildlife.net headquarters to feed and refresh. For those among you who may enjoy an opportunity to see an interesting variety of native birds living around your place, we’ve assembled a list of our five favorite foods for wild birds.
The selections on our list are foods that provide supplemental nutrition and/or energy for indigenous species, mostly songbirds, without sustaining your neighborhood’s non-native European Starlings and House Sparrows, mooching Eastern Gray Squirrels, or flock of ecologically destructive hand-fed waterfowl. We’ve included foods that aren’t necessarily the cheapest but are instead those that are the best value when offered properly.
Number 5
Raw Beef Suet
In addition to rendered beef suet, manufactured suet cakes usually contain seeds, cracked corn, peanuts, and other ingredients that attract European Starlings, House Sparrows, and squirrels to the feeder, often excluding woodpeckers and other native species from the fare. Instead, we provide raw beef suet.
Because it is unrendered and can turn rancid, raw beef suet is strictly a food to be offered in cold weather. It is a favorite of woodpeckers, nuthatches, and many other species. Ask for it at your local meat counter, where it is generally inexpensive.
Number 4
Niger (“Thistle”) Seed
Niger seed, also known as nyjer or nyger, is derived from the sunflower-like plant Guizotia abyssinica, a native of Ethiopia. By the pound, niger seed is usually the most expensive of the bird seeds regularly sold in retail outlets. Nevertheless, it is a good value when offered in a tube or wire mesh feeder that prevents House Sparrows and other species from quickly “shoveling” it to the ground. European starlings and squirrels don’t bother with niger seed at all.
Niger seed must be kept dry. Mold will quickly make niger seed inedible if it gets wet, so avoid using “thistle socks” as feeders. A dome or other protective covering above a tube or wire mesh feeder reduces the frequency with which feeders must be cleaned and moist seed discarded. Remember, keep it fresh and keep it dry!
Number 3
Striped Sunflower Seed
Striped sunflower seed, also known as grey-striped sunflower seed, is harvested from a cultivar of the Common Sunflower (Helianthus annuus), the same tall garden plant with a massive bloom that you grew as a kid. The Common Sunflower is indigenous to areas west of the Mississippi River and its seeds are readily eaten by many native species of birds including jays, finches, and grosbeaks. The husks are harder to crack than those of black oil sunflower seed, so House Sparrows consume less, particularly when it is offered in a feeder that prevents “shoveling”. For obvious reasons, a squirrel-proof or squirrel-resistant feeder should be used for striped sunflower seed.
Number 2
Mealworms
Mealworms are the commercially produced larvae of the beetle Tenebrio molitor. Dried or live mealworms are a marvelous supplement to the diets of numerous birds that might not otherwise visit your garden. Woodpeckers, titmice, wrens, mockingbirds, warblers, and bluebirds are among the species savoring protein-rich mealworms. The trick is to offer them without European Starlings noticing or having access to them because European Starlings you see, go crazy over a meal of mealworms.
Number 1
Food-producing Native Shrubs and Trees
The best value for feeding birds and other wildlife in your garden is to plant food-producing native plants, particularly shrubs and trees. After an initial investment, they can provide food, cover, and roosting sites year after year. In addition, you’ll have a more complete food chain on a property populated by native plants and all the associated life forms they support (insects, spiders, etc.).
Your local County Conservation District is having its annual spring tree sale soon. They have a wide selection to choose from each year and the plants are inexpensive. They offer everything from evergreens and oaks to grasses and flowers. You can afford to scrap the lawn and revegetate your whole property at these prices—no kidding, we did it. You need to preorder for pickup in the spring. To order, check their websites now or give them a call. These food-producing native shrubs and trees are by far the best bird feeding value that you’re likely to find, so don’t let this year’s sales pass you by!
You say you really don’t want to take a look back at 2020? Okay, we understand. But here’s something you may find interesting, and it has to do with the Susquehanna River in 2020.
As you may know, the National Weather Service has calculated the mean temperature for the year 2020 as monitored just upriver from Conewago Falls at Harrisburg International Airport. The 56.7° Fahrenheit value was the highest in nearly 130 years of monitoring at the various stations used to register official climate statistics for the capital city. The previous high, 56.6°, was set in 1998.
Though not a prerequisite for its occurrence, record-breaking heat was accompanied by a drought in 2020. Most of the Susquehanna River drainage basin experienced drought conditions during the second half of the year, particularly areas of the watershed upstream of Conewago Falls. A lack of significant rainfall resulted in low river flows throughout late summer and much of the autumn. Lacking water from the northern reaches, we see mid-river rocks and experience minimal readings on flow gauges along the lower Susquehanna, even if our local precipitation happens to be about average.
Back in October, when the river was about as low as it was going to get, we took a walk across the Susquehanna at Columbia-Wrightsville atop the Route 462/Veteran’s Memorial Bridge to have a look at the benthos—the life on the river’s bottom.
These improvements in water quality and wildlife habitat can have a ripple effect. In 2020, the reduction in nutrient loads entering Chesapeake Bay from the low-flowing Susquehanna may have combined with better-than-average flows from some of the bay’s lesser-polluted smaller tributaries to yield a reduction in the size of the bay’s oxygen-deprived “dead zones”. These dead zones typically occur in late summer when water temperatures are at their warmest, dissolved oxygen levels are at their lowest, and nutrient-fed algal blooms have peaked and died. Algal blooms can self-enhance their severity by clouding water, which blocks sunlight from reaching submerged aquatic plants and stunts their growth—making quantities of unconsumed nutrients available to make more algae. When a huge biomass of algae dies in a susceptible part of the bay, its decay can consume enough of the remaining dissolved oxygen to kill aquatic organisms and create a “dead zone”. The Chesapeake Bay Program reports that the average size of this year’s dead zone was 1.0 cubic miles, just below the 35-year average of 1.2 cubic miles.
Back on a stormy day in mid-November, 2020, we took a look at the tidal freshwater section of Chesapeake Bay, the area known as Susquehanna Flats, located just to the southwest of the river’s mouth at Havre de Grace, Maryland. We wanted to see how the restored American Eelgrass beds there might have fared during a growing season with below average loads of nutrients and life-choking sediments spilling out of the nearby Susquehanna River. Here’s what we saw.
We noticed a few Canvasbacks (Aythya valisineria) on the Susquehanna Flats during our visit. Canvasbacks are renowned as benthic feeders, preferring the tubers and other parts of submerged aquatic plants (a.k.a. submersed aquatic vegetation or S.A.V.) including eelgrass, but also feeding on invertebrates including bivalves. The association between Canvasbacks and eelgrass is reflected in the former’s scientific species name valisineria, a derivitive of the genus name of the latter, Vallisneria.
The plight of the Canvasback and of American Eelgrass on the Susquehanna River was described by Herbert H. Beck in his account of the birds found in Lancaster County, Pennsylvania, published in 1924:
“Like all ducks, however, it stops to feed within the county less frequently than formerly, principally because the vast beds of wild celery which existed earlier on broads of the Susquehanna, as at Marietta and Washington Borough, have now been almost entirely wiped out by sedimentation of culm (anthracite coal waste). Prior to 1875 the four or five square miles of quiet water off Marietta were often as abundantly spread with wild fowl as the Susquehanna Flats are now.”
Beck quotes old Marietta resident and gunner Henry Zink:
“Sometimes there were as many as 500,000 ducks of various kinds on the Marietta broad at one time.”
The abundance of Canvasbacks and other ducks on the Susquehanna Flats would eventually plummet too. In the 1950s, there were an estimated 250, 000 Canvasbacks wintering on Chesapeake Bay, primarily in the area of the American Eelgrass, a.k.a. Wild Celery, beds on the Susquehanna Flats. When those eelgrass beds started disappearing during the second half of the twentieth century, the numbers of Canvasbacks wintering on the bay took a nosedive. As a population, the birds moved elsewhere to feed on different sources of food, often in saltier estuarine waters.
Canvasbacks were able to eat other foods and change their winter range to adapt to the loss of habitat on the Susquehanna River and Chesapeake Bay. But not all species are the omnivores that Canvasbacks happen to be, so they can’t just change their diet and/or fly away to a better place. And every time a habitat like the American Eelgrass plant community is eliminated from a region, it fragments the range for each species that relied upon it for all or part of its life cycle. Wildlife species get compacted into smaller and smaller suitable spaces and eventually their abundance and diversity are impacted. We sometimes marvel at large concentrations of birds and other wildlife without seeing the whole picture—that man has compressed them into ever-shrinking pieces of habitat that are but a fraction of the widespread environs they once utilized for survival. Then we sometimes harass and persecute them on the little pieces of refuge that remain. It’s not very nice, is it?
By the end of 2020, things on the Susquehanna were getting back to normal. Near normal rainfall over much of the watershed during the final three months of the year was supplemented by a mid-December snowstorm, then heavy downpours on Christmas Eve melted it all away. Several days later, the Susquehanna River was bank full and dishing out some minor flooding for the first time since early May. Isn’t it great to get back to normal?
SOURCES
Beck, Herbert H. 1924. A Chapter on the Ornithology of Lancaster County, Pennsylvania. The Lewis Historical Publishing Company. New York, NY.
White, Christopher P. 1989. Chesapeake Bay, Nature of the Estuary: A Field Guide. Tidewater Publishers. Centreville, MD.
So you aren’t particularly interested in a stroll through the Pennsylvania woods during the gasoline and gunpowder gang’s second-biggest holiday of the year—the annual sacrifice-of-the-White-tailed-Deity ritual. I get it. Two weeks and nothing to do. Well, why not try a hike through the city instead? I’m not kidding. You might be surprised at what you see. Here are some photographs taken today during several strolls in Harrisburg, Pennsylvania.
First stop was City Island in the Susquehanna River—accessible from downtown Harrisburg or the river’s west shore by way of the Market Street Bridge.
Okay, City Island was worth the effort. Next stop is Wildwood Park, located along Industrial Road just north of the Pennsylvania Farm Show complex and the Harrisburg Area Community College (HACC) campus. There are six miles of trails surrounding mile-long Wildwood Lake within this marvelous Dauphin County Parks Department property.
And now, without further ado, it’s time for the waterfowl of Wildwood Lake—in order of their occurrence.
See, you don’t have to cloak yourself in bright orange ceremonial garments just to go for a hike. Go put on your walking shoes and a warm coat, grab your binoculars and/or camera, and have a look at wildlife in a city near you. You never know what you might find.
SOURCES
Taylor, Scott A., Thomas A. White, Wesley M. Hochachka, Valentina Ferretti, Robert L. Curry, and Irby Lovette. 2014. “Climate-Mediated Movement of an Avian Hybrid Zone”. Current Biology. 24:6 pp.671-676.
Nothing says Happy Valentine’s Day like a really bad poem, so here it is…
FOR THE LOVE OF DUCKS
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
My neighbors are complainin’
I can hear them talk
The mallards eat their garden
Let surprises on their walk
Dung stains on the carpets
They tracked it in the house
It’s from those ducks and not the pets
Can’t blame it on the spouse
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
Tamed with bread and crackers
I gave them as a treat
I soon found maimed dead quackers
Lying in the street
A driver who intended
To miss the hens and drakes
Had their car rear-ended
When they hit the brakes
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
The flock is very wasteful
Each bird a pound a day
Web-foots in a cesspool
Pollute the waterway
There are some kids playing
In that filthy ditch
Soon they’ll be displaying
The rash of Swimmer’s Itch
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
These ducks they do not migrate
They’re here day in, day out
Aquatic life they decimate
No plants, no fish, no trout
Hurry! Hurry! Heed my call
Before it starts to rain
Ten more ducklings took a fall
And are stranded in a drain
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
Have you people lost your minds?
I see you by your fence
These ducks are cute and I am kind
It’s you who’ve lost your sense
Beggars from the handouts
My God what have I done?
Their senseless habits leave no doubt
Their instincts are all gone
I like to feed the duckies
Try it and you’ll see
Aren’t they really lucky?
Relying just on me
Now I know just what to do
Like one would teach a child
I’ll feed the ducks at the zoo
And let the rest live wild
So if you feed the duckies
Beware of the spell
Or you will do the same as me
Loving ducks to death as well
—Ducks Anonymous, LLC
Inside the doorway that leads to your editor’s 3,500 square foot garden hangs a small chalkboard upon which he records the common names of the species of birds that are seen there—or from there—during the year. If he remembers to, he records the date when the species was first seen during that particular year. On New Year’s Day, the results from the freshly ended year are transcribed onto a sheet of notebook paper. On the reverse, the names of butterflies, mammals, and other animals that visited the garden are copied from a second chalkboard that hangs nearby. The piece of paper is then inserted into a folder to join those from previous New Year’s Days. The folder then gets placed back into the editor’s desk drawer beneath a circular saw blade and an old scratched up set of sunglasses—so that he knows exactly where to find it if he wishes to.
A quick glance at this year’s list calls to mind a few recollections.
Before putting the folder back into the drawer for another year, the editor decided to count up the species totals on each of the sheets and load them into the chart maker in the computer.
Despite the habitat improvements in the garden, the trend is apparent. Bird diversity has not cracked the 50 species mark in 6 years. Despite native host plants and nectar species in abundance, butterfly diversity has not exceeded 10 species in 6 years.
It appears that, at the very least, the garden habitat has been disconnected from the home ranges of many species by fragmentation. His little oasis is now isolated in a landscape that becomes increasingly hostile to native wildlife with each passing year. The paving of more parking areas, the elimination of trees, shrubs, and herbaceous growth from the large number of rental properties in the area, the alteration of the biology of the nearby stream by hand-fed domestic ducks, light pollution, and the outdoor use of pesticides have all contributed to the separation of the editor’s tiny sanctuary from the travel lanes and core habitats of many of the species that formerly visited, fed, or bred there. In 2019, migrants, particularly “fly-overs”, were nearly the only sightings aside from several woodpeckers, invasive House Sparrows (Passer domesticus), and hardy Mourning Doves. Even rascally European Starlings became sporadic in occurrence—imagine that! It was the most lackluster year in memory.
If habitat fragmentation were the sole cause for the downward trend in numbers and species, it would be disappointing, but comprehendible. There would be no cause for greater alarm. It would be a matter of cause and effect. But the problem is more widespread.
Although the editor spent a great deal of time in the garden this year, he was also out and about, traveling hundreds of miles per week through lands on both the east and the west shores of the lower Susquehanna. And on each journey, the number of birds seen could be counted on fingers and toes. A decade earlier, there were thousands of birds in these same locations, particularly during the late summer.
In the lower Susquehanna valley, something has drastically reduced the population of birds during breeding season, post-breeding dispersal, and the staging period preceding autumn migration. In much of the region, their late-spring through summer absence was, in 2019, conspicuous. What happened to the tens of thousands of swallows that used to gather on wires along rural roads in August and September before moving south? The groups of dozens of Eastern Kingbirds (Tyrannus tyrannus) that did their fly-catching from perches in willows alongside meadows and shorelines—where are they?
Several studies published during the autumn of 2019 have documented and/or predicted losses in bird populations in the eastern half of the United States and elsewhere. These studies looked at data samples collected during recent decades to either arrive at conclusions or project future trends. They cite climate change, the feline infestation, and habitat loss/degradation among the factors contributing to alterations in range, migration, and overall numbers.
There’s not much need for analysis to determine if bird numbers have plummeted in certain Lower Susquehanna Watershed habitats during the aforementioned seasons—the birds are gone. None of these studies documented or forecast such an abrupt decline. Is there a mysterious cause for the loss of the valley’s birds? Did they die off? Is there a disease or chemical killing them or inhibiting their reproduction? Is it global warming? Is it Three Mile Island? Is it plastic straws, wind turbines, or vehicle traffic?
The answer might not be so cryptic. It might be right before our eyes. And we’ll explore it during 2020.
In the meantime, Uncle Ty and I going to the Pennsylvania Farm Show in Harrisburg. You should go too. They have lots of food there.
A steady stream of birds was on the move this morning over Conewago Falls. There were hundreds of Ring-billed Gulls, scores of Herring Gulls, and a few Great Black-backed Gulls to dominate the flight. Then too there were thirteen Mallards, Turkey Vultures and a Black Vulture, twenty or more American Robins, a half a dozen Bald Eagles (juvenile and immature birds), a couple of Red-winged Blackbirds, and, perhaps most unusual of all, a flock of a dozen Scoters (Melanitta species), a waterfowl typical of the Mid-Atlantic surf in winter. All of these birds were diligently following the river, and into a headwind no less.
“Hold on just a minute there, buster,” you may say, “I’ve looked at the migration count by dutifully clicking on the logo above and there is nothing but zeroes on the count sheet for today. The season totals have not changed since the previous count day!”
Ah-ha, my dedicated friend, correct you are. It seems that today’s bird flight was solely in one direction. And that direction was upriver, moving north into a north breeze, on a heading which conflicts with all logic for creatures that should still be headed south for winter. As a result, none of the birds observed today were counted on the “Autumn Migration Count”.
You might say, “Don’t you know that Winter Solstice was three days ago, so autumn and autumn migration is over.”
Okay, point well taken. I should therefore clarify that what we title as “Autumn Migration Count” is more accurately a census of birds, insects, and other creatures transiting from northerly latitudes to more favorable latitudes to the south for winter. This transit can begin as early as late June and extend into the first weeks of winter. While most of this movement is motivated by the reduced hours of daylight during the period, late season migrants are often responding to ice, bad weather, or lack of food to prompt a journey further south. Migration south in late December and January occurs even while the amount of daylight is increasing slightly in the days following the Winter Solstice.
So what of the birds seen flying north today? There was some snow cover that has melted away, and the ice that formed on the river a week ago is gone due to the milder than normal temperatures this week.
One may ask, “Were the birds seen today migrating north?”
Let’s look at the species seen moving upriver today a try to determine their motivation.
First, and perhaps most straight-forward, is the huge flight of gulls. Wintering gulls on the Susquehanna River near Conewago Falls tend to spend their nights in flocks on the water or on treeless islands and rocky outcrops in the river. Many hundreds, sometimes thousands, find such favorable sites along the fifteen mile stretch of river from Conewago Falls downstream to Lake Clarke and the Conejohela Flats at Washington Boro. Each morning most of these gulls venture out to suburbia, farmland, landfill, hydroelectric dams, and other sections of river in search of food. Gulls are very able fliers and easily cover dozens of miles outbound and inbound each day in search of food. Many of the gulls seen this morning were probably on their way to the Harrisburg metropolitan area to eat trash. Barring any extraordinary buildups of ice on this section of river, one would expect these gulls to remain and make these daily excursions to food sources through early spring.
Second, throughout the season Bald Eagles have been tallied on the migration count with caution. Flight altitude, behavior, plumage, and the reaction of the “local” eagles to these transients was carefully considered before counting an eagle as a migrant. They roam a lot, particularly when young, and range widely to feed. The movement of eagles up the river today was probably food related. A gathering of adult, juvenile, and immature Bald Eagles could be seen more than a half mile upstream from the migration count lookout. Those moving up the river seemed to assemble with the “locals” there throughout the morning. White-tailed Deities occasionally drown, particularly when there is thin or unstable ice on the river (as there was last week) and they attempt to tread upon it. Then, their bodies are often stranded among rocks, in trees, or on the crown of the dam. After such a mishap, their carcasses become meals for carrion-eaters in the falls. Such an unfortunate deity, or another source of food, may have been attracting the eagles in numbers today.
Next, Black and Turkey Vultures often roam widely in search of food. The small numbers seen headed up-river today would tend to mean very little when trying to determine if there is a trend or population shift. Again, food may have been luring them upriver from nearby roosts.
And finally, the scoters, Mallards, American Robins, and Red-winged Blackbirds may have been wandering as well. Toward mid-day, the wind speed picked up and the direction changed to the east. This raises the possibility that these and others of the birds seen today may sense a change in weather, and may seek to take flight from the inclement conditions. Prompted by the ocean breeze and in an attempt to avoid a storm, was there some movement away from the Atlantic Coastal Plain to the upper Piedmont today? Many species may make these types of reactive movements. Is it possible that some birds flee or avoid ever-changing storm tracks and alter there wintering locations based on jet streams, water currents, and other climatic conditions? Probably. These are interesting dynamics and something worthy of study outside the simpler methods of a migration count.
…And if it snows that stretch down south won’t ever stand the strain… –Jimmy Webb
The lower Susquehanna valley’s first snowfall of the season arrived yesterday. By this morning it measured just an inch in depth at Conewago Falls, more to the south and east, less to the west and north. By mid-morning a cold fresh to moderate breeze from the northwest was blowing through the falls and stirring up ripples on the river.
Gulls sailed high overhead on the wind, taking a speedy ride downriver toward Chesapeake Bay, the Atlantic coast, and countless fast-food restaurant parking lots where surviving winter weather is more of a sure thing. Nearly a thousand Ring-billed Gulls soared past the migration count lookout today. Thirteen Herring Gulls and four Great Black-backed Gulls were among them.
Other migrants today included a Mallard, twenty-nine American Black Ducks, two Bald Eagles, eleven Black Vultures, fifteen Turkey Vultures, five American Goldfinches, and fifteen Red-winged Blackbirds. The wintery weather seems to be prompting these late-season travelers to be on their way.
You know, today was like many other days at the falls. As I arrive, I have the habit of checking all the power line towers on both river shorelines to see what may be there awaiting discovery. More often than not, something interesting is perched on one or more of the structures…
Yes friends, while the birds migrated through high above, down below a coordinated effort was underway to replace some of the electric transmission cable that stretches across the Susquehanna River at Conewago Falls. As you’ll see, this project requires precise planning, preparation, and skill. And it was fascinating to watch!
The humid rainy remains of Hurricane Nate have long since passed by Pennsylvania, yet mild wet weather lingers to confuse one’s sense of the seasons. This gloomy misty day was less than spectacular for watching migrating birds and insects, but some did pass by. Many resident animals of the falls are availing themselves of the opportunity to continue active behavior before the cold winds of autumn and winter force a change of lifestyle.
Warm drizzle at daybreak prompted several Northern Spring Peepers (Pseudacris crucifer crucifer) to begin calling from the wetlands in the Riparian Woodlands of Conewago Falls. An enormous chorus of these calls normally begins with the first warm rains of early spring to usher in this tiny frog’s mating season. Today, it was just a few “peeps” among anxious friends.
Any additional river flow that resulted from the rains of the previous week is scarcely noticeable among the Pothole Rocks. The water level remains low, the water column is fairly clear, and the water temperatures are in the 60s Fahrenheit.
It’s no real surprise then to see aquatic turtles climbing onto the boulders in the falls to enjoy a little warmth, if not from the sun, then from the stored heat in the rocks. As usual, they’re quick to slide into the depths soon after sensing someone approaching or moving nearby. Seldom found anywhere but on the river, these skilled divers are Common Map Turtles (Graptemys geographica), also known as Northern Map Turtles. Their paddle-like feet are well adapted to swimming in strong current. They are benthic feeders, feasting upon a wide variety of invertebrates found among the stone and substrate of the river bottom.
Adult Common Map Turtles hibernate communally on the river bottom in a location protected from ice scour and turbulent flow, often using boulders, logs, or other structures as shelter from strong current. The oxygenation of waters tumbling through Conewago Falls may be critical to the survival of the turtles overwintering downstream. Dissolved oxygen in the water is absorbed by the nearly inactive turtles as they remain submerged at their hideout through the winter. Though Common Map Turtles, particularly males, may occasionally move about in their hibernation location, they are not seen coming to the surface to breathe.
The Common Map Turtles in the Susquehanna River basin are a population disconnected from that found in the main range of the species in the Great Lakes and upper Mississippi basin. Another isolated population exists in the Delaware River.
SOURCES
Committee on the Status of Endangered Wildlife in Canada. 2002. Status Report of the Northern Map Turtle. Canadian Wildlife Service. Ottawa, Ontario.
A fresh breeze from the north brought cooler air and a reminder that summer is gone and autumn has arrived.
Fast-moving dark clouds provided a perfect backdrop for viewing passing diurnal migrants. Bald Eagles utilized the tail wind to cruise down the Susquehanna toward Chesapeake Bay and points further south. A migrating Merlin began a chase from which a Northern Flicker narrowly escaped by finding shelter among Pothole Rocks and a few small trees. The season’s first American Black Duck (Anas rubripes), Common Loon (Gavia immer), Yellow-bellied Sapsucker (Sphyrapicus varia), and American Pipits (Anthus rubescens) moved through.
Blue Jays continued their hesitant crossings of the river at Conewago Falls. The majority completed the journey by forming groups of a dozen or more birds and following the lead of a lone American Robin, a Northern Flicker, or, odd as it appeared, a small warbler.
By far the most numerous migrants today were swallows. Thousands of Northern Rough-winged Swallows and hundreds of Tree Swallows were on the wing in search of what was suddenly a sparse flying insect supply. To get out of the brisk wind, some of the more resourceful birds landed on the warm rocks. To satisfy their appetite, many were able to pick crawling arthropods from the surface of the boulders. They swallow them whole.
The Neotropical birds that raised their young in Canada and in the northern United States have now logged many miles on their journey to warmer climates for the coming winter. As their density decreases among the masses of migrating birds, a shift to species with a tolerance for the cooler winter weather of the temperate regions will be evident.
Though it is unusually warm for this late in September, the movement of diurnal migrants continues. This morning at Conewago Falls, five Broad-winged Hawks (Buteo platypterus) lifted from the forested hills to the east, then crossed the river to continue a excursion to the southwest which will eventually lead them and thousands of others that passed through Pennsylvania this week to wintering habitat in South America. Broad-winged Hawks often gather in large migrating groups which swarm in the rising air of thermal updrafts, then, after gaining substantial altitude, glide away to continue their trip. These ever-growing assemblages from all over eastern North America funnel into coastal Texas where they make a turn to south around the Gulf of Mexico, then continue on toward the tropics. In the coming weeks, a migration count at Corpus Christi in Texas could tally 100,000 or more Broad-winged Hawks in a single day as a large portion of the continental population passes by. You can track their movement and that of other diurnal raptors as recorded at sites located all over North America by visiting hawkcount.org on the internet. Check it out. You’ll be glad you did.
Nearly all of the other migrants seen today have a much shorter flight ahead of them. Red-bellied Woodpeckers (Melanerpes carolinus), Red-headed Woodpeckers (Melanerpes erythrocephalus), and Northern Flickers (Colaptes auratus) were on the move. Migrating American Robins (Turdus migratorius) crossed the river early in the day, possibly leftovers from an overnight flight of this primarily nocturnal migrant. The season’s first Great Black-backed Gulls (Larus marinus) arrived. American Goldfinches are easily detected by their calls as they pass overhead. Look carefully at the goldfinches visiting your feeder, the birds of summer are probably gone and are being replaced by migrants currently passing through.
By far, the most conspicuous migrant today was the Blue Jay. Hundreds were seen as they filtered out of the hardwood forests of the diabase ridge to cautiously cross the river and continue to the southwest. Groups of five to fifty birds would noisily congregate in trees along the river’s edge, then begin flying across the falls. Many wary jays abandoned their small crossing parties and turned back. Soon, they would try the trip again in a larger flock.
A look at this morning’s count reveals few Neotropical migrants. With the exception of the Broad-winged Hawks and warblers, the migratory species seen today will winter in a sub-tropical temperate climate, primarily in the southern United States, but often as far north as the lower Susquehanna River valley. The individual birds observed today will mostly continue to a winter home a bit further south. Those that will winter in the area of Conewago Falls will arrive in October and later.
The long-distance migrating insect so beloved among butterfly enthusiasts shows signs of improving numbers. Today, more than two dozen Monarchs were seen crossing the falls and slowly flapping and gliding their way to Mexico.