The Fog of a January Thaw

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.

York Haven Dam Powerhouse
After freezing to a slushy consistency earlier this week, the Susquehanna is already beginning to thaw.   Below the York Haven Dam at Conewago Falls, the water is open and ice-free.
Mallards and a pair of American Wigeon on a frozen lake.
On frozen man-made lakes and ponds, geese and ducks like these Mallards and American Wigeon are presently concentrated around small pockets of open water.
American Robin in a Callery pear
During the past ten days, American Robin numbers have exploded throughout the lower Susquehanna valley.  The majority of these birds may be a mix of both those coming south to escape the late onset of wintry conditions to our north and those inching north into our region as early spring migrants.
American Robin
The January thaw has melted the snow from lawns and fields to provide thousands of visiting robins with a chance to forage for earthworms.
Cooper's Hawk
A visit by this young Cooper’s Hawk to the susquehannnawildlife.net headquarters garden sent songbirds scrambling…
Eastern Gray Squirrel
…but did nothing to unnerve our resident Eastern Gray Squirrels,…
Eastern Gray Squirrel
…which promptly went into tail-waving mode to advertise their presence.
Red-tailed Hawk
But earlier in the week, when heavy snow cover in the rural areas surrounding our urbanized neighborhood made it difficult for rodent-eating raptors to find food, we received brief visits from both a Red-tailed Hawk…
Red-shouldered Hawk
…and this young Red-shouldered Hawk, an uncommon bird of prey most often found in wet woods and other lowlands.
Eastern Gray Squirrel
To escape notice during visits by these larger raptors, our squirrels remained motionless and commenced performance of their best bump-on-a-log impressions.
Red-shouldered Hawk in flight.
Unimpressed, each of our visiting buteos remained for just a few minutes before moving on in search of more favorable hunting grounds and prey.
Early Successional Growth
As snow melted and exposed bare ground in fields of early successional growth, we encountered…
White-crowned Sparrow
…a flock of White-crowned Sparrows, most in first-winter plumage…
American Tree Sparrow
…and at least a dozen American Tree Sparrows.  During the twentieth century, these handsome songbirds were regular winter visitors to the lower Susquehanna region.  During recent decades, they’ve become increasingly more difficult to find.  Currently, moderate numbers appear to be arriving to escape harsher weather to our north.
Adult Male Northern Harrier
What could be more appropriate on a foggy, gray evening than finding a “gray ghost” (adult male Northern Harrier) patrolling the fields in search of mice and voles.

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…

Pileated Woodpecker in Silver Maple
The maroon-red flower buds of Silver Maples are beginning to swell.  And woodpeckers including Pileated Woodpeckers are beginning to drum, a timber-pounding behavior they use to establish breeding territories in habitats with suitable sites for cavity nesting.
Skunk Cabbage
In wet soil surrounding spring seeps and streams, Skunk Cabbage is rising through the leaf litter to herald the coming of a new season.  Spring must surely be just around the corner.

Shorebirds and More at Bombay Hook National Wildlife Refuge

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.

2023-2024 Federal Duck Stamp. Your Federal Duck Stamp is your free pass to visit the nation's National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.
Your Federal Duck Stamp is your admission ticket for entry into many of the country’s National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.

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.

Northern Bobwhite
This pair of Northern Bobwhite, a species now extirpated from the Lower Susquehanna River Watershed and the rest of Pennsylvania, escorted us into the refuge.  At Bombay Hook, they don’t waste your money mowing grass.  Instead, a mosaic of warm-season grasses and early successional growth creates ideal habitat for Northern Bobwhite and other wildlife.
Shearness Pool at Bombay Hook N.W.R.
Twice each day, high tide inundates mudflats in the saltwater tidal marshes at Bombay Hook prompting shorebirds to move into the four man-made freshwater pools.  Birds there can often be observed at close range.  The auto tour route through the refuge primarily follows a path atop the dikes that create these freshwater pools.  Morning light is best when viewing birds on the freshwater side of the road, late-afternoon light is best for observing birds on the tidal saltwater side.
Great Blue Heron
A Great Blue Heron at high tide on the edge of a tidal creek that borders Bombay Hook’s tour route at Raymond Pool.
Semipalmated Sandpipers
Semipalmated Sandpipers stream into Raymond Pool to escape the rising tide in the salt marsh.
Semipalmated Sandpipers and Short-billed Dowitcher
More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.
Short-billed Dowitchers
Two more Short-billed Dowitchers on the way in.
Sandpipers, Avocets, Egrets, and Mallards
Recent rains have flooded some of the mudflats in Bombay Hook’s freshwater pools. During our visit, birds were often clustered in areas where bare ground was exposed or where water was shallow enough to feed.  Here, Short-billed Dowitchers in the foreground wade in deeper water to probe the bottom while Semipalmated Sandpipers arrive to feed along the pool’s edge.  Mallards, American Avocets, and egrets are gathered on the shore.
Short-billed Dowitchers
More Short-billed Dowitchers arriving to feed in Raymond Pool.
Semipalmated Sandpipers
Hundreds of Semipalmated Sandpipers gathered in shallow water where mudflats are usually exposed during mid-summer in Raymond Pool.
Hundreds of Semipalmated Sandpipers, several Short-billed Dowitchers, and some Forster’s Terns (Sterna forsteri) crowd onto a mud bar at Bear Swamp Pool.
Semipalmated Sandpipers, Forster's Terns, and a Short-billed Dowitcher
A zoomed-in view of the previous image showing a tightly packed crowd of Semipalmated Sandpipers, Forster’s Terns, and a Short-billed Dowitcher (upper left).
Short-billed Dowitchers
Short-billed Dowitchers wading to feed in the unusually high waters of Raymond Pool.
Short-billed Dowitchers, American Avocets, and a Snowy Egret
Short-billed Dowitchers, American Avocets, and a Snowy Egret in Raymond Pool.  A single Stilt Sandpiper (Calidris himantopus) can been seen flying near the top of the flock of dowitchers just below the egret.
Stilt Sandpiper among Short-billed Dowitchers
Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.
American Avocets
American Avocets probe the muddy bottom of Raymond Pool.
Dunlin and Short-billed Dowitchers
Among these Short-billed Dowitchers, the second bird from the bottom is a Dunlin. This sandpiper, still in breeding plumage, is a little bit early.  Many migrating Dunlin linger at Bombay Hook into October and even November.
Least Sandpiper
This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool
Greater Yellowlegs
A Greater Yellowlegs at Bear Swamp Pool.
Caspian Tern
A Caspian Tern patrolling Raymond Pool.
Marsh Wren singing
The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.
Marsh Wren Nest
This dome-shaped Marsh Wren nest is supported by the stems of Saltwater Cordgrass (Sporobolus alterniflorus), a plant also known as Smooth Cordgrass.  High tide licks at the roots of the cordgrass supporting the temporary domicile.
Seaside Dragonlet
By far the most common dragonfly at Bombay Hook is the Seaside Dragonlet (Erythrodiplax berenice).  It is our only dragonfly able to breed in saltwater.  Seaside Dragonlets are in constant view along the impoundment dikes in the refuge.
Red-winged Blackbird
Red-winged Blackbirds are still nesting at Bombay Hook, probably tending a second brood.
Bobolink
Look up!   A migrating Bobolink passes over the dike at Shearness Pool.
Mute Swans and Canada Geese
Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.
Trumpeter Swans
A pair of Trumpeter Swans (Cygnus buccinator) as seen from the observation tower at Shearness Pool.  Unlike gregarious Tundra and Mute Swans, pairs of Trumpeter Swans prefer to nest alone, one pair to a pond, lake, or sluggish stretch of river.  The range of these enormous birds was restricted to western North America and their numbers were believed to be as low as 70 birds during the early twentieth century.  An isolated population consisting of several thousand birds was discovered in a remote area of Alaska during the 1930s allowing conservation practices to protect and restore their numbers.  Trumpeter Swans are slowly repopulating scattered east coast locations following recent re-introduction into suitable habitats in the Great Lakes region.
Great Egret
A Great Egret prowling Shearness Pool.
Snowy Egret
A Snowy Egret in Bear Swamp Pool.
A hen Wood Duck (second from right) escorts her young.
Wood Ducks in Bear Swamp Pool.
Black-necked Stilt and young.
A Bombay Hook N.W.R. specialty, a Black-necked Stilt and young at Bear Swamp Pool.

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.

Bombay Hook National Wildlife Refuge protects a vast parcel of tidal salt marsh and an extensive network of tidal creeks. These areas are not only essential wildlife habitat, but are critical components for maintaining water quality in Delaware Bay and the Atlantic.
Atlantic Horseshoe Crab
The shells of expired Atlantic Horseshoe Crabs were formerly widespread and common among the naturally occurring flotsam along the high tide line on Delaware Bay.  We found just this one during our visit to Bombay Hook.  Man has certainly decimated populations of this ancient crustacean during recent decades.
As the tide goes out, it’s a good time for a quick walk into the salt marsh on the boardwalk trail opposite Raymond Pool.
Atlantic Marsh Fiddler Crabs
Among the Saltmarsh Cordgrass along the trail and on the banks of the tidal creek there, a visitor will find thousands and thousands of Atlantic Marsh Fiddler Crabs (Minuca pugnax).
Atlantic Marsh Fiddler Crabs
Atlantic Marsh Fiddler Crabs and their extensive system of burrows help prevent the compaction of tidal soils and thus help maintain ideal conditions for the pure stands of Saltwater Cordgrass that trap sediments and sequester nutrients in coastal wetlands.
Atlantic Marsh Fiddler Crab
A male Atlantic Marsh Fiddler Crab peers from its den.
Great Egret
Herons and egrets including this Great Egret are quite fond of fiddler crabs.  As the tide goes out, many will venture away from the freshwater pools into the salt marshes to find them.
Green Heron
A Green Heron seen just before descending into the cordgrass to find fiddler crabs for dinner.
Clapper Rail
A juvenile Clapper Rail (Rallus crepitans crepitans) emerges from the cover of the cordgrass along a tidal creek to search for a meal.
Glossy Ibis
Glossy Ibis leave their high-tide hiding place in Shearness Pool to head out into the tidal marshes for the afternoon.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide in the marshes opposite Shearness Pool.
Ospey
An Osprey patrols the vast tidal areas opposite Shearness Pool.

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.

Indigo Bunting
Indigo Buntings nest in areas of successional growth and yes, that is a Spotted Lanternfly on the grape vine at the far right side of the image.
Blue Grosbeak
Blue Grosbeaks (Passerina caerulea) are common nesting birds at Bombay Hook.  This one was in shrubby growth along the dike at the north end of Shearness Pool.
Trumpet Creeper and Poison Ivy
These two native vines are widespread at Bombay Hook and are an excellent source of food for birds. The orange flowers of the Trumpet Vine are a hummingbird favorite and the Poison Ivy provides berries for numerous species of wintering birds.
Pileated Woodpecker in Sweet Gum
The Pileated Woodpecker is one of the numerous birds that supplements its diet with Poison Ivy berries.  The tree this individual is visiting is an American Sweetgum (Liquidambar styraciflua), a species native to the Atlantic Coastal Plain in Delaware.  The seed balls are a favorite winter food of goldfinches and siskins.
Red-bellied Slider and Painted Turtle
Finis Pool has no frontage on the tidal marsh but is still worth a visit.  It lies along a spur road on the tour route and is located within a deciduous coastal plain forest.  Check the waters there for basking turtles like this giant Northern Red-bellied Cooter (Pseudemys rubiventris) and much smaller Painted Turtle.
White-tailed Deity
The White-tailed Deity is common along the road to Finis Pool.
Fowler's Toad
Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.
Turk's Cap Lily
The National Wildlife Refuge System not only protects animal species, it sustains rare and unusual plants as well.  This beauty is a Turk’s Cap Lily (Lilium superbum), a native wildflower of wet woods and swamps.
Wild Turkey
Just as quail led us into the refuge this morning, this Wild Turkey did us the courtesy of leading us to the way out in the afternoon.

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.

Are Your Eggs All They’re Cracked Up To Be?

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.

A farm with a biosecurity perimeter or control area.  (United States Department of Agriculture Animal and Plant Inspection Service image)
A U.S.D.A. Animal and Plant Inspection Service Veterinary Services employee decontaminates footwear at the entrance to a biosecurity zone.  (United States Department of Agriculture Animal and Plant Inspection Service image)

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.

Black Vultures
Black Vultures and other scavengers including Bald Eagles are attracted to improperly discarded poultry carcasses and will often loiter in areas where dumping occurs.

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.

Striped Skunk
Striped Skunks and many other mammals are readily attracted by improperly discarded poultry carcasses.

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.

An offshoot of the Green Revolution, a large-scale poultry operation.
Modern science has produced a genetic map of the domestic chicken (Gallus gallus domesticus) allowing faster development of varieties with improved disease resistance, productivity, and other traits.  (United States Department of Agriculture image by Peggy Greb)
A technician checks eggs produced by immunized birds for the presence of flu virus.  A flu vaccine could provide an added layer of protection to biosecurity in the poultry industry.  (United States Department of Agriculture image by Stephen Ausmus)

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.

Live poultry and eggs are frequently sold to and traded among operators of backyard flocks without monitoring for disease.  (United States Department of Agriculture image by Keith Weller.)

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.

What’s in your eggs?  (United States Department of Agriculture image by Peggy Greb)

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.

A commercial poultry operation (in this case turkeys) produces economical consumer products.  (United States Department of Agriculture image by Scott Bauer)

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.

An outdoor flock of backyard chickens.  (United States Department of Agriculture Animal and Plant Inspection Service image)

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.

Variation produced under domestication has left poultry unfit for life among the perils found outdoors.  (United States Department of Agriculture image)
Turkey Vulture and White-tailed Deer
Millions of years of natural selection have made scavengers and predators ideally suited for the role of detecting and consuming dead, dying, and diseased wild animals, thus reducing accumulations of rotting carcasses and the spread of infectious pathogens among prey species.  Their distribution and reproductive success is closely controlled by the availability of food.  Humans need not disturb this balance or create unnatural congregations of these animals by providing supplemental foods such as dead poultry.

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.

Outside and Inside Animals
It’s as simple as ABC and 123.
Cage-free chickens can be housed within the protective envelop of a building where they can be segregated from the microbes and pollutants found outdoors.  The U.S.D.A. defines “free-range” poultry as birds with some access to an outdoor setting where the benefits of biosecurity and quarantine are, for all intents and purposes, nullified.  (United States Department of Agriculture image by Stephen Ausmus)
Pigs
Pigs raised outdoors by homesteaders and hobby farmers pose the threat of spreading a number of diseases including Swine Fevers and Brucellosis into pork industry operations.   Escaped individuals are often attracted to commercial hog houses where they can loiter outside and contaminate the ground surrounding entrance ways used by personnel tending the animals.  Like other domestic animals, pigs should be contained inside buildings for biosecurity.
Dairy cows in an indoor feed lot.
Dairy cows and other cattle raised within well-designed indoor and semi-indoor settings are less prone to injury and consumption of contaminated foods and water.
Domestic Cat
Domestic Cats (Felis catus), particularly when allowed to roam outdoors, can contract the parasite Toxoplasma gondii during interactions with mice.  Humans, dogs, pigs, and other animals coming in contact with the Toxoplasma oocysts shed in feline feces can contract Toxoplasmosis, a disease with various physical and mental health symptoms.  According to the Centers for Disease Control, there are approximately three million cases of Toxoplasmosis among humans in the United States annually.

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.

Stained slide of cow brain tissue affected by Bovine Spongiform Encephalopathy (BSE). The pale-colored air pockets are voids in the tissue caused by the disease.  (United States Department of Agriculture image by the late Dr. Al Jenny)

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…

Dairy cows in a pasture.
Bovine Spongiform Encephalopathy (BSE), also known as Mad Cow Disease, is a neurodegenerative disorder fatal to cattle.  It is caused by the same prion that, when consumed or otherwise contracted by humans, causes Creutzfekd-Jokob Disease (CJD).
Chronic Wasting Disease (CWD), a fatal disease caused by a prion, is currently spreading among populations of the White-tailed Deity in the mid-Atlantic region.  Prions are understood to be folded proteins, not living things, thus they are not destroyed by cooking and other disinfection practices.  If you are wondering whether various forms of these pathogens will begin accumulating in the environment and affecting more and more species with new and more frightening afflictions, well, time will tell.  Meanwhile, we at susquehannawildlife.net are staying away from “game” and any other form of bush meat.  Thanks, but no thanks!
The future with a safe food supply will require domestic animals to be contained indoors while wildlife roams unmolested outdoors.

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.

Five Best Values for Feeding Birds

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.

American Goldfinches in drab winter (basic) plumage visit the trickle of water entering the headquarters pond to bathe and drink.  In addition to offering the foods animals need to survive, a source of clean water is an excellent way to attract wildlife to your property.

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.

Bread, “bargain” seed mixes, and cracked corn can attract and sustain large numbers of House Sparrows and European Starlings.  Both are non-native species that compete mercilessly with indigenous birds including bluebirds for food and nesting sites.  Though found favorable for feeding Northern Cardinals without attracting squirrels, the expensive safflower seed seen here is another favorite of these aggressive House Sparrows.  Ever wasteful, they “shovel” seed out of feeders while searching for the prime morsels from which they can easily remove the hulls.  Trying not to feed them is an ongoing challenge, so we don’t offer these aforementioned foods to our avian guests.

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.

Raw beef suet is fat removed from areas surrounding the kidneys on a beef steer.  To avoid spoiling, offer it only in the winter months, particularly if birds are slow to consume the amount placed for them.  If temperatures are above freezing, it’s important to replace uneaten food frequently.  The piece seen here on the left was stored in the freezer for almost a year while the rancid piece to the right was stored in a refrigerator at about 40 degrees Fahrenheit for just two months.  You can render raw beef suet and make your own cakes by melting it down and pouring it into a form such as cupcake tin.  But do it outdoors or you’ll be living alone for a while.
A female Downy Woodpecker feeds on raw beef suet stuffed into holes drilled into a vertically hanging log.  Because they can’t be cleaned, log feeders should be discarded after one season.  Wire cage feeders though, can usually be scrubbed, disinfected, dried, and reused.
Pesky European Starlings might visit a raw beef suet feeder but won’t usually linger unless other foods to their liking are available nearby.
This male Downy Woodpecker has no trouble feeding on raw beef suet packed into holes drilled into the underside of this horizontally hanging log.  Starlings don’t particularly care to feed this way.
Unusual visitors like a Brown Creeper are more likely to stop by at a suet feeder when it isn’t crowded by raucous starlings, House Sparrows, and squirrels.   This one surprised us just this morning.
Below the feeders, scraps of suet that fall to the ground are readily picked up, usually by ground-feeding birds.  In this instance, a male Eastern Bluebird saw a chunk break loose and pounced on it with haste.

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!

Niger (“thistle”) seed is very small, so it is offered in specialized feeders to prevent seed from spilling out of oversize holes as waste.
An American Goldfinch in winter plumage feeding on niger seed from a wire mesh feeder.  By April, goldfinches are molting into spectacular breeding feathers.  Niger seed can be offered year-round to keep them visiting your garden while they are at maximum magnificence.
American Goldfinches in August.  This tube feeder is designed specifically for goldfinches, birds that have no difficulty hanging upside down to grab niger seed from small feeding ports.
During invasion years, visiting Pine Siskins favor niger seed at feeding stations.
Like goldfinches, Pine Siskins are quite comfortable feeding upside down on specialized tubes with perches positioned above the seed ports.  Seeds dropped to the ground are readily picked up by ground-feeding birds including Mourning Doves and Dark-eyed Juncos.  Periodically, uneaten niger seed should be swept up and discarded.

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.

Striped sunflower seed.
A male House Finch and a Carolina Chickadee pluck striped sunflower seeds from a squirrel-resistant powder-coated metal-mesh tube feeder.
An American Goldfinch in winter plumage finds striped sunflower seeds irresistible, even with niger seed being offered in an adjacent feeder.
A Tufted Titmouse visits a feeder stocked with striped sunflower seeds.
Northern Cardinals readily feed on striped sunflower seeds, especially those that fall from our metal-mesh tube feeders.
An Eastern Gray Squirrel (Sciurus carolinensis) has no choice but to be satisfied with striped sunflower seeds that spill from our wire-mesh tube feeders.

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.

Dried mealworms can be offered in a cup or on a tray feeder.  Live mealworms need to be contained in a steep-sided dish, so they don’t crawl away.  Unless you’re really lucky, you’ll probably have to place your serving vessel of mealworms inside some type of enclosure to exclude European Starlings.
A male Eastern Bluebird tossing and grabbing a dried mealworm.
A female Eastern Bluebird with a dried mealworm.
A pair of Eastern Bluebirds.  The value of mealworms is self-evident: you get to have bluebirds around.

 

To foil European Starlings, we assembled this homemade mealworm feeder from miscellaneous parts. The bluebirds took right to it.
It frustrates the starlings enough to discourage them from sticking around for long.
If you’re offering dried mealworms, a source of clean water must be available nearby so that the bluebirds and other guests at your feeder don’t become dehydrated.

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.).

In your garden, a Northern Mockingbird may defend a food supply like these Common Winterberry fruits as its sole means of sustenance for an entire winter season.  Having an abundance of plantings assures that in your cache there’s plenty to eat for this and other species.
The American Goldfinches currently spending the winter at our headquarters are visiting the feeders for niger and striped sunflower seeds, but the bulk of their diet consists of tiny seeds from the cones on our Eastern Hemlock trees.  At night, birds obtain shelter from the weather by roosting in this clump of evergreens.
While the Eastern Bluebirds visiting the susquehannawildlife.net headquarters are fond of mealworms, the bulk of their diet here consists of these Common Winterberry fruits and the berries on our American Holly trees.
Cedar Waxwings are readily attracted to red berries including Common Winterberry fruit.
Migrating American Robins visit the headquarters garden in late winter each year to devour berries before continuing their journey to the north.

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!

2020: A Good Year

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.

As we begin our stroll across the river, we quickly notice Mallards and a Double-crested Cormorant (far left) feeding among aquatic plants.  You can see the leaves of the vegetation just breaking the water’s surface, particularly behind the feeding waterfowl.  Let’s have a closer look.
An underwater meadow of American Eelgrass (Vallisneria americana) as seen from atop the Veteran’s Memorial Bridge at Columbia-Wrightsville.  Also known as Freshwater Eelgrass, Tapegrass, and Wild Celery, it is without a doubt the Susquehanna’s most important submerged aquatic plant.  It grows in alluvial substrate (gravel, sand, mud, etc.) in river segments with moderate to slow current.  Water three to six feet deep in bright sunshine is ideal for its growth, so an absence of flooding and the sun-blocking turbidity of muddy silt-laden water is favorable.
Plants in the genus Vallisneria have ribbon-like leaves up to three feet in length that grow from nodes rooted along the creeping stems called runners.  A single plant can, over a period of years, spread by runners to create a sizable clump or intertwine with other individual plants to establish dense meadows and an essential wildlife habitat.
An uprooted segment of eelgrass floats over a thick bed of what may be parts of the same plant.  Eelgrass meadows on the lower Susquehanna River were decimated by several events: deposition of anthracite coal sediments (culm) in the late-nineteenth and early-twentieth centuries, dredging of the same anthracite coal sediments during the mid-twentieth century, and the ongoing deposition of sediments from erosion occurring in farm fields, logged forests, abandoned mill ponds, and along denuded streambanks.  Not only has each of these events impacted the plants physically by either burying them or ripping them out by the roots, each has also contributed to the increase in water turbidity (cloudiness) that blocks sunlight and impairs their growth and recovery.
A submerged log surrounded by beds of eelgrass forms a haven for fishes in sections of the river lacking the structure found in rock-rich places like Conewago Falls.  A period absent of high water and sediment runoff extended through the growing season in 2020 to allow lush clumps of eelgrass like these to thrive and further improve water quality by taking up nutrients, particularly nitrogen and phosphorus.  Nutrients used by vascular plants including eelgrass become unavailable for feeding detrimental algal blooms in downstream waters including Chesapeake Bay.
Small fishes and invertebrates attract predatory fishes to eelgrass beds.  We watched this Smallmouth Bass leave an ambush site among eelgrass’s lush growth to shadow a Common Carp as it rummaged through the substrate for small bits of food.  The bass would snatch up crayfish that darted away from the cover of stones disturbed by the foraging carp.
Sunfishes are among the species taking advantage of eelgrass beds for spawning.  They’ll build a nest scrape in the margins between clumps of plants allowing their young quick access to dense cover upon hatching.  The abundance of invertebrate life among the leaves of eelgrass nourishes feeding fishes, and in turn provides food for predators including Bald Eagles, this one carrying a freshly-caught Bluegill.

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 followed the signs from Havre de Grace to Swan Harbor Farm Park.
Harford County Parks and Recreation’s Swan Harbor Farm Park consists of a recently-acquired farming estate overlooking the tidal freshwater of Susquehanna Flats.
Along the bay shore, a gazebo and a fishing pier have been added.  Both provide excellent observation points.
The shoreline looked the way it should look on upper Chesapeake Bay, a vegetated buffer and piles of trees and other organic matter at the high-water line.  There was less man-made garbage than we might find following a summer that experienced an outflow from river flooding, but there was still more than we should be seeing.
Judging by the piles of fresh American Eelgrass on the beach, it looks like it’s been a good year.  Though considered a freshwater plant, eelgrass will tolerate some brackish water, which typically invades upper Chesapeake Bay each autumn due to a seasonal reduction in freshwater inflow from the Susquehanna and other tributaries.  Saltwater can creep still further north when the freshwater input falls below seasonal norms during years of severe drought.  The Susquehanna Flats portion of the upper bay very rarely experiences an invasion by brackish water; there was none in 2020.
As we scanned the area with binoculars and a spotting scope, a raft of over one thousand ducks and American Coots (foreground) could be seen bobbing among floating eelgrass leaves and clumps of the plants that had broken away from their mooring in the mud.  Waterfowl feed on eelgrass leaves and on the isopods and other invertebrates that make this plant community their home.
While coots and grebes seemed to favor the shallower water near shore, a wide variety of both diving and dabbling ducks were widespread in the eelgrass beds more distant.  Discernable were Ring-necked Ducks, scaup, scoters, Long-tailed Ducks, Redheads, American Wigeons, Gadwall, Ruddy Ducks, American Black Ducks, and Buffleheads.

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.

Canvasbacks on Chesapeake Bay.  (United States Fish and Wildlife Service image by Ryan Hagerty)

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?

The rain-and-snow-melt-swollen Susquehanna from Chickies Rock looking upriver toward Marietta during the high-water crest on December 27th.
Cresting at Columbia as seen from the Route 462/Veteran’s Memorial Bridge.  A Great Black-backed Gull monitors the waters for edibles.
All back to normal on the Susquehanna to end 2020.
Yep, back to normal on the Susquehanna.  Maybe 2021 will turn out to be another good year, or maybe it’ll  just be a Michelin or Firestone.

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.

City Life: Gulls, Dabbling Ducks, and More

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.

From the middle of the Susquehanna River, City Island offers a spectacular view of the downtown Harrisburg skyline.  In summer, it’s the capital city’s playground.  During the colder months, it’s a great place to take a quiet walk and find unusual birds.
This Bald Eagle was in mature trees along the river shoreline near the Harrisburg Senator’s baseball stadium.
Ring-billed Gulls gather on the “cement beach” at the north end of City Island.
One of a dozen or so Herring Gulls seen from the island’s north end. This particular bird is a juvenile.
A Ring-billed Gull and some petite Bonaparte’s Gulls.  Really good birders will tell you to always check through flocks of these smaller gulls carefully.  It turns out they’re onto something.  Look closely at the gull to the right.
A bright red bill and more of a crescent shape to the black spot behind the eye, that’s an adult Black-headed Gull (Chroicocephalus ridibundus) in winter plumage, a rare bird on the Susquehanna.  Black-headed Gulls have colonized North America from Europe, breeding in Iceland, southernmost Greenland, and rarely Newfoundland.

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.

A flock of Killdeer at the south end of Wildwood Lake.  From November through February, a walk along the south and west sides of the impoundment can be a photographer’s dream. The light is suitable in the morning, then just keeps getting better as the day wears on.
Is this probable Carolina/Black-capped Chickadee hybrid a resident at Wildwood or just a visitor from a few miles to the north?  Currently, pure Black-capped Chickadees (Poecile atricapillus) nest in the mountains well to the north of Harrisburg, and pure Carolina Chickadees nest south of the city.  Harrisburg possibly remains within the intergrade/hybrid zone, an area where the ranges of the two species overlap, but probably not for long.  During recent decades, this zone has been creeping north, at times by as much as a half mile or more each year.  So if the capital city isn’t Carolina Chickadee territory yet, it soon will be.
Another chickadee likely to be a hybrid, this one with some white in the greater wing coverts like a Black-capped, but with a call even more rapid than that of the typical Carolina, the species known for uttering the faster “chick-a-dee-dee-dee”.  It sounded wired, like it had visited a Starbucks all morning.
In the lower Susquehanna valley, Carolina Chickadees have already replaced hybrids and pure Black-capped Chickadees as nesting birds in the Piedmont hills south of Harrisburg and the Great Valley.  This Carolina Chickadee was photographed recently in the Furnace Hills at Middle Creek Wildlife Management Area in northern Lancaster County.  The transition there was probably complete by the end of the twentieth century.  Note the characteristic overall grayish appearance of the wings and the neat lower border of the black bib on this bird, 
For comparison, a bird presumed to be a pure Black-capped Chickadee photographed earlier this month in Lebanon County, Pennsylvania.  This fall, “Black-caps”, like many other northern perching birds, are moving south to invade the lower elevations and milder climes of the Piedmont and Atlantic Coastal Plain Provinces.  Note the extensive areas of white in the wings, the long tail, the buffy flanks, and the jagged edge of the black bib.
Along Wildwood Lake’s west shore, an adult male Sharp-shinned Hawk was soon attracted to the commotion created by bantering chickadees and other songbirds.
Yellow during the first year, the eyes of the Sharp-shinned Hawk get redder as the bird ages.
Also along the west border of Wildwood Lake, temperatures were warm enough to inspire Painted Turtles (Chrysemys picta) to seek a sun bath atop logs in the flooded portions of the abandoned Pennsylvania Canal.

And now, without further ado, it’s time for the waterfowl of Wildwood Lake—in order of their occurrence.

A pair of Wood Ducks (hen left, drake right) with American Black Ducks and Canada Geese.
A pair of Northern Pintails.
A pair of American Wigeons (Mareca americana).
A hen (left) and drake (right) Gadwall.
Mallards.
A female Northern Shoveler.
An American Black Duck.
Canada Geese.
You just knew there had to be a booby prize, a “Blue Suede” (a.k.a. Blue Swede), a domestic variety of Mallard.
It’s a Green-winged Teal (Anas crecca) sampler.  Clockwise from left: a juvenile male, a female, and an adult male.
A drake and two hen Green-winged Teal.  Isn’t that great light by late afternoon?

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.

Really Bad Poetry

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

 

They’re cute, but if you really love waterfowl, then please refrain from feeding them.  Hand-fed ducks soon lose their survival instincts.  These clueless birds do dumb things like loiter in traffic and, perhaps worst of all, omit migration from their yearly life cycle.  Daily plundering by year-round congregations of Canada Geese, Mute Swans, polygamous Mallards (seen here), and domestic waterfowl is decimating native plant and animal populations in waterways, wetlands, ponds, and lakes throughout the Lower Susquehanna River Watershed.  For aquatic food chains and fisheries to recover, people must stop feeding (and releasing) these highly-impressionable birds.

Clean Slate for 2020

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.

The 2019 bird list included 48 species, the 47 on the board plus Ruby-throated Hummingbird, which was logged on a slip of paper found tucked into the edge of the frame.

This Green Frog, photographed on New Year’s Day 2019, was “out and about” along the edge of the editor’s garden pond.  Due to the recent mild weather, Green Frogs were active during the current New Year’s holiday as well.
On a day with strong south winds in late February or during the first two weeks of March, there is often a conspicuous northbound spring flight of migrating waterfowl, gulls, and songbirds that crosses the lower Susquehanna valley as it departs Chesapeake Bay.  These Tundra Swans were among the three thousand seen from the garden patio on March 13, 2019.  A thousand migrating Canada Geese, 500 Red-winged Blackbirds, numerous Ring-billed Gulls, and some Herring Gulls were seen during the same afternoon.
This juvenile Cooper’s Hawk was photographed through the editor’s kitchen window.  From its favorite perch on this arbor it would occasionally find success snagging a House Sparrow from the large local flock.  It first visited the garden in November, the species being absent there since early spring.  Unlike previous years, there was no evidence of a breeding pair in the vicinity during 2019.
Plantings that provide food and cover for wildlife are essential to their survival.  Native flowers including Trumpet Vine (Campsis radicans) and Partridge Pea provide nourishment for the Ruby-throated Hummingbirds that visit the editor’s garden, but they really love a basket or pot filled with Mexican Cigar (Cuphea ignea) too.  The latter (seen here) can be grown as a houseplant and moved outdoors to a semi-shaded location in summer and early fall.  But remember, it’s tropical, so you’ll need to bring it back inside when frost threatens.
A Swamp Sparrow is an unusual visitor to a small property surrounded by paved parking lots and treeless lawns.  Nevertheless, aquatic gardens and native plants helped to attract this nocturnal migrant, seen here eating seeds from Indiangrass.  It arrived on September 30 and was gone on October 2.

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.

The Tufted Titmouse was a daily visitor to the garden through 2018.  This one was photographed investigating holes in an old magnolia there during the spring of that year.  There were no Tufted Titmouse sightings in the garden in 2019.  This and other resident species, especially cavity-nesters, appear to be experiencing at least a temporary decline.
Breeding birds including Northern Cardinals may have had a difficult year.  In the editor’s garden, a pair were still feeding and escorting one of their young in early October.  The infestation of the editor’s town by domestic house and feral cats may have contributed to the failure of earlier broods, but a lack of food is also a likely factor.

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.

At about the time of summer solstice in June each year, Common Grackles begin congregating into roving summer flocks that will grow in size to assure their survival during the autumn migration, winter season, and return north in the spring.  From his garden, the editor saw just one flock of less than a dozen birds during the summer of 2019.  He saw none during his journeys through other areas of the Susquehanna valley.  Flocks of one hundred birds or more did not materialize until the southbound movements of grackles passed through the region in October and November.

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.

A clean slate for 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.

Migrating North?

CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS

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.

Ring-billed Gulls fly upriver through the Pothole Rocks at Conewago Falls.
Herring Gulls stream upriver through Conewago Falls on their way to fine dining.

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.

A distant gathering of Bald Eagles at the south end of Three Mile Island in upper Conewago Falls.

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.

A Ring-billed Gull begins feeding as storm clouds approach Conewago Falls at mid-day.  This and other gull species travel widely in their winter range to find food and safe roosting sites.  For them, northward spring migration usually begins no earlier than late February.

Conewago Lineman

…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.

Light snow on the Conewago Falls Pothole Rocks this morning.

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.

CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS

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…

…sometimes there are large flocks of European Starlings…
…other times there might be one or more Turkey Vultures…
…or possibly a Bald Eagle or two…
…or maybe the fastest-flying bird on the planet…
…or perhaps, wait; what’s he doing up there?

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!

A helicopter is used to raise/lower men and equipment to/from the top of the towers.
A crew doing preparation work is lifted from a tower on the west shore of Conewago Falls.
A crew member is raised to a tower on the east shore of Conewago Falls to begin the next phase of the project.
Crew members are positioned on the two towers on the west shore.
The helicopter hovers in a stand-by position above the Pothole Rocks.  By keeping the chopper downwind from and below the wires being replaced, the pilot avoids putting rotor wash into the work area.   Note the linemen on the upper left side of each tower.  These men monitored the pulleys as the old cable, followed by the new, was pulled from the west shore to the east.
At the ready, the pilot skillfully hovers his craft, nose into the gusty wind, just 100 feet to the east of the migration count site on the Pothole Rocks.
Even as the chopper maintained position near and immediately over the count lookout, migrating birds continued to be seen streaming in a downriver direction high above.
A migrating immature Bald Eagle passes overhead, apparently undaunted by the commotion created by the use of a helicopter to tend the crew advancing replacement wire across the river below.
With the new cable in place, workers are lifted from the towers and lowered to the ground where they can get out of the cold wind after a job well done.

State of Confusion

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.

The tiny Northern Spring Peeper is recognized by the dark “X” across its back.  Soon, shelter must be found among loose bark and fallen logs to commence hibernation.  Emergence, often prompted by warm spring rains, will quickly be followed by a growing chorus of breeding calls as sometimes hundreds of these frogs assemble in vernal pools where mating will then occur.

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.

Common Map Turtles, including this recently hatched young seen in August, are often observed climbing onto rocks in the river.
Note the oversize swimming fin adaptations of the feet on this adult Common Map Turtle found among the Pothole Rocks in Conewago Falls.  Young and adults are capable of navigating some strong current to feed and escape danger.
CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS

SOURCES

Committee on the Status of Endangered Wildlife in Canada.  2002.  Status Report of the Northern Map Turtle.  Canadian Wildlife Service.  Ottawa, Ontario.

Swallows by the Thousands

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.

A few of the thousands of swallows seen at Conewago Falls today.
CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS

Blue Jay Way

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.

Sensing that they are being watched, Blue Jays are hesitant to fly across the narrow Susquehanna at Conewago Falls without first assembling into a flock.  The local constabulary often penalizes those who freelance and do not move in orderly groups.

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 Great Blue Heron (Ardea herodius) can be found year-round at Conewago Falls, provided there is open water and adequate food.  Migrants from breeding colonies to the north will soon supplement the local population.
The Double-crested Cormorant (Phalacrocorax auritus) is a summer resident at Conewago Falls.  Migration of the local population and of those from further north will soon begin.  All will be gone by the time ice forms on the river.  Cormorants are often seen drying their feathers in sunlight following a series of feeding dives.

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.

CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS