Want Healthy Floodplains and Streams? Want Clean Water? Then Make Room for the Beaver

I’m worried about the beaver.  Here’s why.

Imagine a network of brooks and rivulets meandering through a mosaic of shrubby, sometimes boggy, marshland, purifying water and absorbing high volumes of flow during storm events.  This was a typical low-gradient stream in the valleys of the Lower Susquehanna River Watershed in the days prior to the arrival of the trans-Atlantic human migrant.  Then, a frenzy of trapping, tree chopping, mill building, and stream channelization accompanied the east to west waves of settlement across the region.  The first casualty: the indispensable lowlands manager, the North American Beaver (Castor canadensis).

Beaver Traps
Nineteenth-century beaver traps on display in the collection of the State Museum of Pennsylvania in Harrisburg.  Soon after their arrival, Trans-Atlantic migrants (Europeans) established trade ties to the trans-Beringia migrants (“Indians”) already living in the lower Susquehanna valley and recruited them to cull the then-abundant North American Beavers.  By the early 1700s, beaver populations (as well as numbers of other “game” animals) were seriously depleted, prompting the Conoy, the last of the trans-Beringia migrants to reside on the lower Susquehanna, to disperse.  The traps pictured here are samples of the types which were subsequently used by the European settlers to eventually extirpate the North American Beaver from the Lower Susquehanna River Watershed during the 1800s.

Without the widespread presence of beavers, stream ecology quickly collapsed.  Pristine waterways were all at once gone, as were many of their floral and faunal inhabitants.  It was a streams-to-sewers saga completed in just one generation.  So, if we really want to restore our creeks and rivers, maybe we need to give the North American Beaver some space and respect.  After all, we as a species have yet to build an environmentally friendly dam and have yet to fully restore a wetland to its natural state.  The beaver is nature’s irreplaceable silt deposition engineer and could be called the 007 of wetland construction—doomed upon discovery, it must do its work without being noticed, but nobody does it better.

North American Beaver diorama on display in the State Museum of Pennsylvania in Harrisburg.
North American Beaver diorama on display in the State Museum of Pennsylvania in Harrisburg.  Beavers were reintroduced to the Susquehanna watershed during the second half of the twentieth century.
A beaver dam on a small stream in the Lower Susquehanna River Watershed.
A beaver dam and pond on a small stream in the Lower Susquehanna River Watershed.
Floodplain Wetlands Managed by North American Beavers
Beaver dams not only create ponds, they also maintain shallow water levels in adjacent areas of the floodplain creating highly-functional wetlands that grow the native plants used by the beaver for food.  These ecosystems absorb nutrients and sediments.  Prior to the arrival of humans, they created some of the only openings in the vast forests and maintained essential habitat for hundreds of species of plants as well as animals including fish, amphibians, reptiles, and birds.  Without the beaver, many of these species could not, and in their absence did not, exist here.
The beaver lodge provides shelter from the elements and predators for a family of North American Beavers.
Their newly constructed lodge provides shelter from the elements and from predators for a family of North American Beavers.
Sandhill Cranes Visit a Beaver-managed Floodplain in the lower Susquehanna valley
Floodplains managed by North American Beavers can provide opportunities for the recovery of the uncommon, rare, and extirpated species that once inhabited the network of streamside wetlands that stretched for hundreds of miles along the waterways of the Lower Susquehanna River Watershed.
Great Blue Heron
A wintering Great Blue Heron is attracted to a beaver pond by the abundance of fish in the rivulets that meander through its attached wetlands.
Sora Rail in Beaver Pond
Beaver Ponds and their attached wetlands provide nesting habitat for uncommon birds like this Sora rail.
Wood Duck feeding on Lesser Duckweed in Beaver Pond
Lesser Duckweed grows in abundance in beaver ponds and Wood Ducks are particularly fond of it during their nesting cycle.
Sandhill Cranes feeding among Woolgrass in a Beaver Pond
Beaver dams maintain areas of wet soil along the margins of the pond where plants like Woolgrass sequester nutrients and contain runoff while providing habitat for animals ranging in size from tiny insects to these rare visitors, a pair of Sandhill Cranes (Antigone canadensis).
Sandhill Cranes feeding among Woolgrass in a floodplain maintained by North American Beavers.
Sandhill Cranes feeding among Woolgrass in a floodplain maintained by North American Beavers.

Few landowners are receptive to the arrival of North American Beavers as guests or neighbors.  This is indeed unfortunate.  Upon discovery, beavers, like wolves, coyotes, sharks, spiders, snakes, and so many other animals, evoke an irrational negative response from the majority of people.  This too is quite unfortunate, and foolish.

North American Beavers spend their lives and construct their dams, ponds, and lodges exclusively within floodplains—lands that are going to flood.  Their existence should create no conflict with the day to day business of human beings.  But humans can’t resist encroachment into beaver territory.  Because they lack any basic understanding of floodplain function, people look at these indispensable lowlands as something that must be eliminated in the name of progress.  They’ll fill them with soil, stone, rock, asphalt, concrete, and all kinds of debris.  You name it, they’ll dump it.  It’s an ill-fated effort to eliminate these vital areas and the high waters that occasionally inundate them.  Having the audacity to believe that the threat of flooding has been mitigated, buildings and poorly engineered roads and bridges are constructed in these “reclaimed lands”.  Much of the Lower Susquehanna River Watershed has now been subjected to over three hundred years-worth of these “improvements” within spaces that are and will remain—floodplains.  Face it folks, they’re going to flood, no matter what we do to try to stop it.  And as a matter of fact, the more junk we put into them, the more we displace flood waters into areas that otherwise would not have been impacted!  It’s absolute madness.

By now we should know that floodplains are going to flood.  And by now we should know that the impacts of flooding are costly where poor municipal planning and negligent civil engineering have been the norm for decades and decades.  So aren’t we tired of hearing the endless squawking that goes on every time we get more than an inch of rain?  Imagine the difference it would make if we backed out and turned over just one quarter or, better yet, one half of the mileage along streams in the Lower Susquehanna River Watershed to North American Beavers.  No more mowing, plowing, grazing, dumping, paving, spraying, or building—just leave it to the beavers.  Think of the improvements they would make to floodplain function, water quality, and much-needed wildlife habitat.  Could you do it?  Could you overcome the typical emotional response to beavers arriving on your property and instead of issuing a death warrant, welcome them as the talented engineers they are?  I’ll bet you could.

A Visit to a Beaver Pond

To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis).  They first constructed their dam on this small stream about five years ago.  Since then, a flourishing wetland has become established.  Have a look.

A Beaver Pond
Vegetation surrounding the inundated floodplain helps sequester nutrients and sediments to purify the water while also providing excellent wildlife habitat.
A beaver lodge.
The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.
Woolgrass in a beaver pond.
Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.
A male Common Whitetail dragonfly keeping watch over his territory.
A male Common Whitetail dragonfly keeping watch over his territory.
A Twelve-spotted Skimmer perched on Soft Rush.
A Twelve-spotted Skimmer perched on Soft Rush.
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Spicebush Swallowtail visiting Cardinal Flower.
A Spicebush Swallowtail visiting a Cardinal Flower.
Green Heron
A Green Heron looking for small fish, crayfish, frogs, and tadpoles.
A Green Heron stalks potential prey.
The Green Heron stalking potential prey.
A Wood Duck feeding on Lesser Duckweed.
A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).
A Least Sandpiper feeding along the muddy edge of a beaver pond.
A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.
Solitary Sandpiper
A Solitary Sandpiper.
A Solitary Sandpiper testing the waters for proper feeding depth.
A Solitary Sandpiper testing the waters for proper feeding depth.
Pectoral Sandpiper
A Pectoral Sandpiper searches for its next morsel of sustenance.
A Sora rail in a beaver pond.
The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers.  Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.

Isn’t that amazing?  North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems.  Want to clean up the streams and floodplains of your local watershed?  Let the beavers do the job!

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.

A Limpkin’s Journey to Pennsylvania: A Waffle House Serving Escargot at Every Exit

Mid-summer can be a less than exciting time for those who like to observe wild birds.  The songs of spring gradually grow silent as young birds leave the nest and preoccupy their parents with the chore of gathering enough food to satisfy their ballooning appetites.  To avoid predators, roving families of many species remain hidden and as inconspicuous as possible while the young birds learn how to find food and handle the dangers of the world.

But all is not lost.  There are two opportunities for seeing unique birds during the hot and humid days of July.

First, many shorebirds such as sandpipers, plovers, dowitchers, and godwits begin moving south from breeding grounds in Canada.  That’s right, fall migration starts during the first days of summer, right where spring migration left off.  The earliest arrivals are primarily birds that for one reason on another (age, weather, food availability) did not nest this year.  These individuals will be followed by birds that completed their breeding cycles early or experienced nest failures.  Finally, adults and juveniles from successful nests are on their way to the wintering grounds, extending the movement into the months we more traditionally start to associate with fall migration—late August into October.

For those of you who find identifying shorebirds more of a labor than a pleasure, I get it.  For you, July can bring a special treat—post-breeding wanderers.  Post-breeding wanderers are birds we find roaming in directions other than south during the summer months, after the nesting cycle is complete.  This behavior is known as “post-breeding dispersal”.  Even though we often have no way of telling for sure that a wandering bird did indeed begin its roving journey after either being a parent or a fledgling during the preceding nesting season, the term post-breeding wanderer still applies.  It’s a title based more on a bird sighting and it’s time and place than upon the life cycle of the bird(s) being observed.  Post-breeding wanderers are often southern species that show up hundreds of miles outside there usual range, sometimes traveling in groups and lingering in an adopted area until the cooler weather of fall finally prompts them to go back home.  Many are birds associated with aquatic habitats such as shores, marshes, and rivers, so water levels and their impact on the birds’ food supplies within their home range may be the motivation for some of these movements.  What makes post-breeding wanderers a favorite among many birders is their pop.  They are often some of our largest, most colorful, or most sought-after species.  Birds such as herons, egrets, ibises, spoonbills, stilts, avocets, terns, and raptors are showy and attract a crowd.

While it’s often impossible to predict exactly which species, if any, will disperse from their typical breeding range in a significant way during a given year, some seem to roam with regularity.  Perhaps the most consistent and certainly the earliest post-breeding wanderer to visit our region is the “Florida Bald Eagle”.  Bald Eagles nest in “The Sunshine State” beginning in the fall, so by early spring, many of their young are on their own.   By mid-spring, many of these eagles begin cruising north, some passing into the lower Susquehanna valley and beyond.  Gatherings of dozens of adult Bald Eagles at Conowingo Dam during April and May, while our local adults are nesting and after the wintering birds have gone north, probably include numerous post-breeding wanderers from Florida and other Gulf Coast States.

So this week, what exactly was it that prompted hundreds of birders to travel to Middle Creek Wildlife Management Area from all over the Mid-Atlantic States and from as far away as Colorado?

Birders observing something special at Middle Creek Wildlife Management Area on July 10, 2023.

Was it the majestic Great Blue Herons and playful Killdeer?

Great Blue Heron
Great Blue Heron and a Killdeer.

Was it the colorful Green Herons?

Green Heron
Green Heron

Was it the Great Egrets snapping small fish from the shallows?

Great Egret
Great Egret

Was it the small flocks of shorebirds like these Least Sandpipers beginning to trickle south from Canada?

Least Sandpipers
Least Sandpipers

All very nice, but not the inspiration for traveling hundreds or even thousands of miles to see a bird.

It was the appearance of this very rare post-breeding wanderer…

Limpkin at Middle Creek Wildlife Management Area
A Limpkin at Middle Creek Wildlife Management Area in Lancaster County.  The Limpkin (Aramus guarauna) is the only surviving member of the family Aramidae.

…Pennsylvania’s first record of a Limpkin, a tropical wading bird native to Florida, the Caribbean Islands, and South America.  Many observers visiting Middle Creek Wildlife Management Area had never seen one before, so if they happen to be a “lister”, a birder who keeps a tally of the wild bird species they’ve seen, this Limpkin was a “lifer”.

The Limpkin is an inhabitant of vegetated marshlands where it feeds almost exclusively upon large snails of the family Ampullariidae, including the Florida Applesnail (Pomacea paludosa), the largest native freshwater snail in the United States.

Native and Non-native Range of Florida Applesnail
In the United States, the native range of the Limpkin lies within the native range of the Florida Applesnail, shown here in gold.  Introduced populations of the snail are shown in brown.  (United States Geological Survey Nonindigenous Aquatic Species image)
A spectacular nineteenth-century rendition of the Florida Applesnail, including an egg mass, illustrated by Helen E. Lawson in Samuel S. Haldeman’s “Monograph of the Freshwater Univalve Mollusca of the United States”.

Observations of the Limpkin lingering at Middle Creek Wildlife Management Area have revealed a pair of interesting facts.  First, in the absence of Florida Applesnails, this particular Limpkin has found a substitute food source, the non-native Chinese Mystery Snail (Cipangopaludina chinensis).  And second, Chinese Mystery Snails have recently become established in the lakes, pools, and ponds at the refuge, very likely arriving as stowaways on Spatterdock (Nuphar advena) and/or American Lotus (Nelumbo lutea), native transplants brought in during recent years to improve wetland habitat and process the abundance of nutrients (including waterfowl waste) in the water.

A Chinese Mystery Snail.
The Chinese Mystery Snail is the largest freshwater snail in the Lower Susquehanna River Watershed.  (Vintage 35 mm image)
By hitching a ride on aquatic transplants like this Spatterdock, non-native freshwater snails are easily vectored into new areas outside their previous range.
Spatterdock, a native species also known as Yellow Pond Lily or Cow Lily.
Spatterdock, a native species also known as Yellow Pond Lily or Cow Lily, flowering in August.
American Lotus in flower at Middle Creek Wildlife Management Area.
Blooming American Lotus transplants in a pool at Middle Creek Wildlife Management Area during August.
The Limpkin at Middle Creek W.M.A. capturing a Chinese Mystery Snail.
The Limpkin at Middle Creek W.M.A. capturing a Chinese Mystery Snail.
The Limpkin at Middle Creek carrying a Chinese Mystery Snail.
The Limpkin at Middle Creek carrying a Chinese Mystery Snail.
Limpkin holding Chinese Mystery Snail
The Limpkin is seen here maneuvering the the snail in its bill, a set of mandibles specially adapted for extracting the bodies of large freshwater snails from their shells.
Limpkin Grasping Chinese Mystery Snail
The tweezers-like tip of the bill is used to grasp the shell by the rim of the opening or by the “trapdoor” (operculum) that protects the snail inside.
Chinese Mystery Snail
A posed Chinese Mystery Snail showing its “trapdoor”, the operculum protecting the soft body tissue when the animal withdraws inside.  The tips of the Limpkin’s bill close tightly like the end of a tweezers to grasp the operculum and remove it and the snail’s body from the shell.  (Vintage 35 mm image)
Limpkin Removing Chinese Mystery Snail from Shell
The tweezers-tipped bill, which is curved slightly to the right in some Limpkins, is slid into the shell to grasp the snails body and remove it for consumption.  The entire extraction process takes 10 to 30 seconds.

The Middle Creek Limpkin’s affinity for Chinese Mystery Snails may help explain how it was able to find its way to Pennsylvania in apparent good health.  Look again at the map showing the range of the Limpkin’s primary native food source, the Florida Applesnail.  Note that there are established populations (shown in brown) where these snails were introduced along the northern coast of Georgia and southern coast of South Carolina…

Native and Non-native Range of Florida Applesnail
Native (gold) and non-native (brown) ranges of the Florida Applesnail.  (United States Geological Survey Nonindigenous Aquatic Species image)

…now look at the latest U.S.G.S. Nonindigenous Aquatic Species map showing the ranges (in brown) of established populations of non-native Chinese Mystery Snails…

Range (in brown) of established populations of non-native Chinese Mystery Snails.  (United States Geological Survey Nonindigenous Aquatic Species image)

…and now imagine that you’re a happy-go-lucky Limpkin working your way up the Atlantic Coastal Plain toward Pennsylvania and taking advantage of the abundance of food and sunshine that summer brings to the northern latitudes.  It’s a new frontier.  Introduced populations of Chinese Mystery Snails are like having a Waffle House serving escargot at every exit along the way!

Be sure to click the “Freshwater Snails” tab at the top of this page to learn more about the Chinese Mystery Snail and its arrival in the Lower Susquehanna River Watershed.  Once there, you’ll find some additional commentary about the Limpkin and the likelihood of Everglade Snail Kites taking advantage of the presence of Chinese Mystery Snails to wander north.  Be certain to check it out.

Everglade Snail Kite
The endangered Everglade Snail Kite (Rostrhamus sociabilis plumbeus), a Florida Applesnail specialist, has survived in part due to its ability to adapt to eating the non-native Pomacea maculata applesnails which have become widespread in Florida following releases from aquaria.  The adaptation?…a larger body and bill for eating larger snails.  (National Park Service image)

Forty Years Ago in the Lower Rio Grande Valley: Day Three


Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas.  What follows is a daily account of that two-week-long expedition.  Notes logged by Markert some four decades ago are quoted in italics.  The images are scans of 35 mm color slide photographs taken along the way by your editor.


DAY THREE—May 23, 1983

For Russ, Harold, and Steve, this trip would target several bird species each individual had never observed at any prior time in their lives.  Upon seeing a new bird, they could add it to their personal “life list”.  They, like thousands of other “listers”, were dedicated to the goal of having a life list that included over 600 species seen in the American Birding Association (A.B.A.) area—North America north of Mexico.  Harold had traveled throughout much of North America (and the world) and had an A.B.A. life list well in excess of 600 species, thus he had seen nearly all of the regularly occurring birds in the coverage area.  His chance for seeing new species was limited to vagrants that might wander into North America or tropical birds that, over time, had extended their range north of Mexico into the United States.  I don’t recall  how many species Russ and Steve had seen, but I know each had very few opportunities for new finds east of the Rocky Mountains.  For all three of these men, the Lower Rio Grande Valley presented a best bet to add multiple species to their lists.  I had never been south of Cape Hatteras or west of Pennsylvania, so I had the opportunity to add dozens of species to a life list.  Throughout the trip, Russ, Harold, and Steve enthusiastically helped me locate and see new species.  As a result, I saw over 50 new birds to add to my list.

One of the functions of the American Birding Association was to decide which bird species an observer could add to the life list.  The official A.B.A. list was revised regularly to include not only regularly occurring native species, but vagrants as well.  One of the trickier determinations was the status of introduced species.  Back in 1983, a birder could count a Ring-necked Pheasant seen in Pennsylvania on their A.B.A. life list because they were thought to be freely reproducing with a population sustainably established in the state.  Today, they are considered an exotic release and are not countable under A.B.A. rules.

Enter the Black Francolin (Francolinus francolinus), a member of the pheasant family that back in 1983, was countable under A.B.A. rules.  Native to India, the Black Francolin was introduced into southwest Louisiana in 1961 and was apparently reproducing and established.  Russ had a tip that they were seen with some regularity in areas of farmland, marsh, and oil fields south of Vinton, Louisiana.  It was one of this trip’s target species for his life list.

“Ready for Black Francolin.  Up at 5:30 — After breakfast, we went to Gum Cove Road.  No Francolins, but at the end of the blacktop road, we had 5 Purple Gallinules in the scope at one time.  King Rails were plentiful.  We found a dead male Painted Bunting.  Later, we saw a very beautiful live one.  Water everywhere.  Flooded fields everywhere.  The road was flooded for about 50 yards at one point.  White Ibis were abundant.”

Purple Gallinule
Purple Gallinules (Porphyrio martinicus) were common along Gum Cove Road.  In silhouette from a distance, those that were perching atop the shrubs raised hopes that we had located the sought after Blank Francolin, but they were all Purple Gallinules.  We weren’t overly disappointed.  (Vintage 35 mm image)
Painted Bunting
The live male Painted Bunting (Passerina cirus) seen along Gum Cove Road.  (Vintage 35 mm image)

Other sightings of note along Gum Cove Road included: Northern Bobwhite, Common Nighthawk, Cattle Egret, Green Heron, American Bittern, Snowy Egret, Glossy Ibis, Black-necked Stilt (Himantopus mexicanus), Forster’s Tern, Black Tern, Yellow-billed Cuckoo, Eastern Kingbird, Purple Martin, Barn Swallow, Brown Thrasher, Loggerhead Shrike, Red-winged Blackbird, Brown-headed Cowbird, Eastern Meadowlark, Boat-tailed Grackle (Quiscalus major), and Great-tailed Grackle (Quiscalus mexicanus)—a very large and noisy blackbird I had never seen before.

Glossy Ibis
A Glossy Ibis (Plegadis falcinellus) in a flooded area along Gum Cove Road.  (Vintage 35 mm image)

The reader may be interested to know that today, the area between Vinton and the Gulf of Mexico has largely been surrendered to the forces of the hurricanes that strike the region with some regularity.  Cameron Parish* is a sparsely populated buffer zone of marshes, abundant wildlife, and oil and gas wells.  Its population of more than 9,000 in 1983 has plunged to less than 6,000 today.  Hurricane Rita (2005) and Hurricane Ike (2008) precipitated the sharp decline.  The latter hurricane had a 22-foot storm surge that flooded areas 60 miles inland of the coastline.  Following these storms, the majority of severely damaged and destroyed homes were not rebuilt and residents in the most affected areas relocated.  In 2020, Hurricane Laura made landfall at Cameron Parish with record-tying 150 mph winds and a storm surge that pushed flood waters inland to Lake Charles.  Six weeks later, Hurricane Delta followed with 100 mph winds.  For government agencies, the emergency response required by these two storms was minimized by the reduced presence of people and/or their personal property.

* A parish in Louisiana is similar to a county in other states.

Category 4 Hurricane Laura making landfall at Cameron Parish, Louisiana, on August 27, 2020, with wind speeds of 150 mph.  Had this storm come ashore to the east at New Orleans or to the west at Houston, it would have catastrophically impacted a million people or more.  (N.O.A.A./National Weather Service image)

“After a quick stop at the camp grounds, where I slipped and fell in the shower last nite, we headed south.  Larry saw many birds en route.”

Russ took a bad fall on a slippery wet concrete floor and had bruises to show for it.  It worried me; he was 71 years old at the time.  But he was adamant about continuing on and did so with great vigor.

Just hours after a sojourn through the swampy parcels south of Vinton, we were cruising through the metropolis of Houston, Texas, then across a landscape with less cultivated cropland and more scrubland with grazing.  Here and there, but primarily to the east of Houston, blankets of roadside wildflowers painted the landscape with eye-popping color.  Lady Bird Johnson encouraged the plantings soon after she and Lyndon returned to Texas upon leaving life in the White House in 1969.  The sight of those vivid blooms was so memorable and so beautiful.  One couldn’t resist making nasty comparisons to the gobs of mowed grass and mangled trash along the highways back in Pennsylvania.

Birds along the way: Ruby-throated Hummingbird, Common Nighthawk, Black-bellied Whistling Duck, Yellow-crowned Night Heron, Great Blue, Heron, Great Egret, Black Vulture, Turkey Vulture, Red-tailed Hawk, Laughing Gull, Black Tern, Scissor-tailed Flycatcher, Cliff Swallow, Loggerhead Shrike, and Painted Bunting.  I saw my first Black-bellied Whistling Ducks (Dendrocygna autumnalis) and Golden-fronted Woodpecker (Melanerpes aurifrons) near Woodsboro, Texas, and added both to my life list.

“We stopped for the nite at an A OK camp ground 7 miles south of Kingsville.”

Day Three: Vinton, Louisiana, to Kingsville, Texas, a distance of 404 miles.  (United States Geological Survey base image)

Birds at the camp included two Black-bellied Whistling Ducks flying overhead, Common Nighthawk, Golden-fronted Woodpecker, Blue Grosbeak, and another “lifer”—Curve-billed Thrasher (Toxostoma curvirostre).

We also saw a Mexican Ground Squirrel (Ictidomys mexicanus), easily identified by the rows of white spots running the length of its back.

While relaxing at the campsite that evening, we watched the landscape darken and remarked how interesting it was that the glowing red sun had yet to set below the distant horizon—a land so very flat and air so hazy and humid.

Common Nighthawk
We found this Common Nighthawk roosting on a tree limb near our campsite.  During our first few days in Louisiana and Texas, it became increasingly evident that we were in the midst of their peak northbound spring movement.  (Vintage 35 mm image)

The Fallout Continues

Fog and mist lingered throughout the day, as did the migratory water birds on the river and lakes in the lower Susquehanna valley.  As a continuation of yesterday’s post on the fallout, here’s a photo tour of some of the sites where ducks, loons, grebes, and other birds have gathered.

American Robins may have comprised a large portion of the northbound flight appearing on last evening’s radar images.  Today, hundreds could be seen on soggy lawns where earthworms might be found near the surface.  This flock was finding sustenance at Highspire’s Reservoir Park in Dauphin County.
This drake Gadwall (Mareca strepera) and two hens had dropped in for a visit at the Highspire Reservoir Park.
Hundreds of Buffleheads were on the fogged-in Susquehanna River at Harrisburg this afternoon.  From Front Street and Maclay Street in front of the Pennsylvania Governor’s Mansion, they seemed to be everywhere in sight on the rain-swollen current.  After passing downstream, flocks flew in a straight line formation just above the water’s surface as they made a short trip back up the river to then drift down through the channels once again.
A portion of a raft consisting of about three dozen Red-breasted Mergansers floats by the Pennsylvania Governor’s Mansion.  Several of the hundred or more Scaup on the river intermingled with these mergansers from time to time.
A lone Long-tailed Duck (Clanqula hyemalis) near the aforementioned raft of mergansers.  The Long-tailed Duck was formerly known as the Oldsquaw in North America.  The common name used in Britain and Europe is now preferred.
Two of at least a hundred Horned Grebes (Podiceps auritus) seen in the Susquehanna at Harrisburg this afternoon.
American Coots (Fulica americana) at Memorial Lake State Park in Lebanon County.
Buffleheads continue at Memorial Lake.
One more Common Loon than yesterday at Memorial Lake.
A mixed raft of diving ducks and grebes at Memorial Lake.
A closeup of the same raft reveals Buffleheads, Scaup, Ring-necked Ducks, Ruddy Ducks (Oxyura jamaicensis), a Pied-billed Grebe, and Horned Grebes.

Stormy weather certainly is a birder’s delight.