Photo of the Day

Green Frog on Christmas
It’s been a green Christmas at susquehannawildlife.net headquarters.  Among thick growth of Lesser Duckweed and other aquatic plants in the garden ponds, the Green Frogs and their tadpoles remain active.  The water’s open…still no ice here.

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.

The Best Sneakers

When you were young, you may have selected your tennis shoes because they promised to make you run faster and jump higher.  Remember those?  Then as you got a bit older, you may have really wanted the brand that would get you noticed—those overpriced status-symbol athletic shoes.  As the years went by and you put on the extra pounds in all the wrong places, maybe it occurred to you that it might be a really good idea to get some exercise.  So you went out and bought some stylish and expensive fitness footwear that promised to help you run faster and jump higher—and wore that pair to go shopping at the grocery store.  Then you finally realized…

Green Frog in Cheap Sneakers
…that the best sneakers are just something comfortable to loaf around in.
Green Frog in Cheap Sneakers
Wisdom does come with age.

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


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 SIX—May 26, 1983

“Bentsen State Park — Texas”

“Arose at 7:30.  Birded the park and watched for the reported Roadside Hawk.  No luck.  A Roadrunner and Kiskadee was a welcome addition to our list.”

The appearance of Roadside Hawk (Rupornis magnirostris) north of the Rio Grande in Hidalgo County, Texas, was hot news in 1983.  In the weeks leading up to our visit and while we were there, no sightings of this mega-rarity were confirmed.  The reports that were received were not accompanied by photographs or sufficient details to rule out the Hook-billed Kites (Chondrohierax unicinatus) and Cooper’s Hawks that were known to be present.  Roadside Hawk remains a very elusive tropical vagrant in the United States.  It was seen as recently as December of 2018 along the man-made flood control levee to the east of Bentsen-Rio Grande Valley State Park near the Border Patrol Corral and the adjacent National Butterfly Center, neither of which were present in 1983.

Both the Greater Roadrunner (Geococcyx californianus), a familiar member of the cuckoo family (Cuculidae), and the Great Kiskadee (Pitangus sulphuratus), a flycatcher at the northern limit of its range in south Texas, were much anticipated finds at Bentsen-Rio Grande State Park.  We would get better looks at both when we moved to the west in a couple of days.

“Traveled to Brownsville and met Harold and Steve at the airport at 12:30 P.M.”

Back in 1983, the Brownsville Airport was the most frequently used destination for those wanting to fly into the Lower Rio Grande Valley.  Today, Valley International Airport in Harlingen is the busier of the two.  Both of these airports have an interesting history from the World War II years.  Brownsville Airport, renamed Brownsville Army Air Field for the duration of the war, was in use as a base for antisubmarine warfare flights, pilot training, aircraft engine overhauls, and the occasional servicing of B-29 bombers.  The airport in Harlingen was founded during the period as Harlingen Army Air Field and was home to the Harlingen Aerial Gunnery School.  A cheesy Hollywood propaganda movie called Aerial Gunner (1943) was shot there in late 1942 and starred Richard Arlen and a local actress, Amelita (Lita) Ward, who was discovered by the picture’s producers in Harlingen during the early stages of filming.  A young Robert Mitchum portrays one of the gunners.  It’s one of those typical B-movies of the period with a story line that is all mixed up with what happened years ago.  A climactic part of the film depicts students being taken aloft to fire machine guns at kite-like targets being towed behind other training aircraft flying over the nearby Gulf of Mexico.  You can find this classic and watch it for free on the internet.  Afterward, you can go join up if you want, but you can no longer get the war bonds they were selling.

“We tried for the Clay-colored Robin — No Luck.”

Now that Harold and Steve had joined us, we began putting in an earnest effort to find the five species we all needed for our life lists—those Lower Rio Grande Valley exclusives Father Tom had given us directions to find.  First up was Clay-colored Robin, known today as Clay-colored Thrush (Turdus grayi), a brown-colored bird similar to our American Robin.  Its native range in 1983 was from northern Colombia north to the Rio Grande River.  The only pair known to be reliably nesting north of the river in the United States, thus within the A.B.A. listing area, was in Brownsville in a park-like setting on the side of a small hill with a commercial radio station transmitter and antenna on its crest.  It was an easy place to find in the otherwise flat landscape, but we had no luck finding the birds.  Were we too late?  Was nesting season over?  Had the birds already dispersed?

“Visited Santa Ana again and added Ground Dove and White-tailed (Black-shouldered) Kite.”

Father Tom provided us with a tip that Hook-billed Kites had nested in the vicinity of Santa Ana National Wildlife Refuge.  We remained vigilant, but saw none.  The petite Common Ground Dove (Columbina passerina) was harder to locate than I expected, possibly because its small size makes it more prone to depredation than larger doves and pigeons, so it may be a little more secretive.  White-tailed Kite (Elanus leucurus) sightings were a highlight of the trip, so graceful and stunning in appearance, but very wary and distant—not a good photo opportunity.  Other sightings at Santa Ana included the first Harris’s Hawk (Parabuteo unicinctus) of the trip, White-tipped Dove, Groove-billed Ani, Barn Swallow, Black-crested Titmouse, Long-billed Thrasher, a lingering Solitary Vireo, Bronzed Cowbird, Olive Sparrow, and Northern Cardinal.  We heard a Dickcissel (Spiza americana) in a sunflower field by the refuge entrance, but failed to see it.

Harris's Hawk
A Harris’s Hawk at Santa Ana National Wildlife Refuge.  This species is a year-round resident in much of the scrubland of the southwestern United States and Mexico.  (Vintage 35mm image)

Also at Santa Ana N.W.R. a Giant Toad and a Texas Tortoise (Gopherus berlandieri), a scrubland native of south Texas and northern Mexico.

Cane Toad
At Santa Ana National Wildlife Refuge, we stumbled upon this Giant Toad, known today as the Cane Toad, Marine Toad, or Giant Neotropical Toad (Rhinella marina).  It’s range extends from Amazonia north into the Lower Rio Grande Valley.  (Vintage 35 mm image)
Cane Toad
Just how giant is a Giant Toad?  Glad you asked.  That’s a Kennedy half dollar on the ground to its left.  It’s the largest species in the family Bufonidae, the true toads.  And you guessed it, things really are bigger in Texas.  (Vintage 35 mm image)

“We arrived back at Bentsen State Park and I got supper ready while the others birded.  At dusk we saw the Elf Owls again and toured the roads.  Saw two Pauraques.  To bed by 11:15 after a welcome shower.”

A White-eyed Vireo was found during our late afternoon walk.  On a tip from Father Tom, we checked the campground in the area of the east restrooms for nesting Tropical Parulas (Setophaga pitiayumi).  For each of us, it was another of the five target species for the trip.  We heard nothing that resembled this warbler’s song, which sounds very much like that of the Northern Parula with which we were each familiar.

Nightjars are more often seen than heard, so having the opportunity to finish the day watching two Common Pauraques sail across a break in the forest to grab airborne insects was a real treat.

Underwater View of Life in a Vernal Pool

It may look like just a puddle in the woods, but this is a very specialized wetland habitat, a habitat that is quickly disappearing from the Lower Susquehanna River Watershed.  It’s a vernal pool—also known as a vernal pond or an ephemeral (lasting a short time) pool or pond.

Viable vernal pools have several traits in common…

      • They contain water in the spring (hence the name vernal).
      • They have no permanent inflow or outflow of water.
      • They typically dry up during part of the year—usually in late summer.
      • They are fish-free.
      • They provide breeding habitat for certain indicator species of forest-dwelling amphibians and other animals.
      • They are surrounded by forest habitat that supports the amphibians and other vernal pool species during the terrestrial portion of their life cycle.

To have a closer look at what is presently living in this “black leaf” vernal pool, we’re calling on the crew of the S. S. Haldeman to go down under and investigate.

Along the surface of the pool we’re seeing clusters of amphibian eggs, a sign that this pond has been visited by breeding adult frogs and/or salamanders during recent weeks.
Amphibian eggs and the white tail filaments of an invertebrate of interest, Springtime Fairy Shrimp (Eubranchipus vernalis), an endemic of vernal ponds.

Let’s take it down for a better look.  Dive, all dive!

Algae provides food for the shrimp and other inhabitants of the pool.  Leaf litter furnishes hiding places for the pool’s many inhabitants.
These loose clusters of eggs appears to be those of Wood Frogs, a vernal pool indicator species.
Clusters of Wood Frog eggs, the embryos within those in the center of the image less developed than those to the left.
More Wood Frog eggs.  Hatching can take anywhere from two weeks to two months, depending on temperature.
Wood Frog eggs with developing larvae (tadpoles) plainly visible.  The green color of the eggs is created by a symbiotic algae, Oophila amblystomatis, a species unique to vernal pools.  The algae utilizes the waste produced by the developing embryos to fuel its growth and in return releases oxygen into the water during photosynthesis.  Upon hatching, the tadpoles rely upon the algae as one of their principle food sources.
A zoomed-in view showing development of the larvae and what appears to be a tiny invertebrate clinging on the white egg in the upper right.  White eggs don’t hatch and may be infected by a fungus.
Wood Frog eggs and Springtime Fairy Shrimp.
Wood Frog eggs and Springtime Fairy Shrimp.
Springtime Fairy Shrimp swim upside-down.  Note the small, bluish clusters of eggs attached to the abdomens of these females.  Springtime Fairy Shrimp live their entire lives in the vernal pool.  After being deposited in the debris at the bottom of the pool, the eggs will dry out during the summer, then freeze and re-hydrate before hatching during the late winter.
A damselfly larva consuming fairy shrimp.  (Visible in the margin between the uppermost lobes of the dark-colored oak leaf to the right.)
Getting in close we see A) the damselfly larva eating a Springtime Fairy Shrimp and B) one of several discarded exoskeletons of consumed shrimp near this predator.
A fishfly larva (Chauliodinae).  Mosquito numbers are kept in check by the abundance of predators in these pools.
Springtime Fairy Shrimp and a Marbled Salamander (Ambystoma opacum) larva.  The presence of these species confirms this small body of water is a fully-functioning vernal pool.
Springtime Fairy Shrimp and two more larval Marbled Salamanders.  The salamanders’ enlarged gills are necessary to extract sufficient oxygen from the still waters of the pool.
The Marbled Salamander is one of three species of mole salamanders found in the Lower Susquehanna River Watershed.  All breed in vernal pools and live their air-breathing adult lives under the leaves of the forest in subterranean tunnels where they feed on worms and other invertebrates.  Photos of an adult Marbled Salamander and the other two species, Spotted Salamander (Ambystoma maculatum) and Jefferson Salamander (Ambystoma jeffersonianum), can be found by clicking the “Amphibians” tab at the top of this page.
Marbled Salamanders lay their eggs during the fall.  If the bed of the pool is dry at breeding time, the adult female will remain to guard the eggs until rain floods the pool.  The eggs hatch upon inundation, sometimes during the winter.
Marbled Salamanders, like all amphibians that develop in vernal pools, must complete transformation into their air-breathing terrestrial life stage before the pool dries up in the summer heat.
A larval Marbled Salamander explores the bottom of the pool.
A larval Marbled Salamander, Wood Frog eggs, and Springtime Fairy Shrimp, it’s an abundance of life in what at first glance may appear to be just a mud puddle.

We hope you enjoyed this quick look at life in a vernal pool.  While the crew of the S. S. Haldeman decontaminates the vessel (we always scrub and disinfect the ship before moving between bodies of water) and prepares for its next voyage, you can learn more about vernal pools and the forest ecosystems of which they are such a vital component.  Be sure to check out…

If you are a landowner or a land manager, you can find materials specifically providing guidance for protecting, restoring, and re-establishing vernal pool habitats at…

Wood Frogs mating
Wasted Effort-A pair of Wood Frogs mating in a dried-up vernal pool.

These Geese are Outta Here!

Flies?  Cabbage White butterflies?  Can it really be a late-February day?  It certainly is.  Here are a few more signs of an early spring.

Green Frog
Green Frogs were out and about on this balmy February day trying to latch on to one of those flying insects.  Their long winter’s nap lasted just over six weeks.
Common Grackle
Approximately two hundred Common Grackles passed by susquehannawildlife.net headquarters today.  This one stopped to have a look around before continuing its northbound expedition.
Migrating Canada Geese
Difficult to spot, hundreds of high-flying Canada Geese were seen in the hazy sky above the headquarters garden during the late morning.  These migrants are working their way north from Chesapeake Bay and won’t be seen again in our region until fall.

Migratory Waterfowl on Local Ponds and Lakes

Following the deep freeze of a week ago, temperatures soaring into the fifties and sixties during recent days have brought to mind thoughts of spring.  In the pond at susquehannawildlife.net headquarters, Green Frogs are again out and about.

Green Frogs
A pair of Green Frogs seen today alongside the headquarters pond.  A sign of spring?

But is this really an early spring?  Migrating waterfowl indicate otherwise.  Having been forced south from the Great Lakes during the bitter cold snap, a variety of our tardy web-footed friends belatedly arrived on the river and on the Susquehanna Flats of upper Chesapeake Bay about ten days ago.  Now, rising water from snow melt and this week’s rains have forced many of these ducks onto local lakes and ponds where ice coverage has been all but eliminated by the mild weather.  For the most part, these are lingering autumn migrants.  Here’s a sample of some of the waterfowl seen during a tour of the area today…

Snow Geese
Like other late-season migrants, Snow Geese take advantage of open water on area lakes until ice forces them south to the Atlantic Coastal Plain.  In a little more than a month from now, they’ll begin working their way north again.
Tundra Swans and American Black Ducks loafing on an ice-free lake.
Tundra Swans and American Black Ducks loafing on an ice-free lake.
Mute Swans
The non-native Mute Swan has become an invasive species.  Because they are predominantly non-migratory, groups of Mute Swans congregating in valuable wetland habitat can decimate these aquatic ecosystems with their persistent year-round feeding.  Their long necks help them consume enormous quantities of benthic foods that would otherwise be available to migratory diving ducks during their autumn and spring stopovers.
Gadwalls
Small flocks of Gadwalls will sometimes spend the winter on ice-free vegetated ponds in the lower Susquehanna region.
A mixed flock of diving ducks on a small lake.
A mixed flock of diving ducks on a small lake.  Let’s take a closer look!
Redheads, Lesser Scaup, and Canvasback
Six Redheads, three Lesser Scaup (top row left), and a Canvasback (upper right).
Redheads
Redheads.
Buffleheads
Buffleheads.
An adult male Lesser Scaup.
An adult male Lesser Scaup.
Lesser Scaup
A female (right) and a first-winter male (left) Lesser Scaup.
Canvasbacks and a Ruddy Duck
Canvasbacks and a Ruddy Duck.

With the worst of winter’s fury still to come, it’s time to say farewell to most of these travelers for a little while.  With a little luck, we’ll see them again in March or April.

Striped Skunk
Our official susquehannawildlife.net prognosticator climbed out of its winter hideout today to have a look around.   Then, without hesitation, the forecast for 2023 was issued, “Winter Stinks!”

Forest vs. Woodlot

Let’s take a quiet stroll through the forest to have a look around.  The spring awakening is underway and it’s a marvelous thing to behold.  You may think it a bit odd, but during this walk we’re not going to spend all of our time gazing up into the trees.  Instead, we’re going to investigate the happenings at ground level—life on the forest floor.

Rotting logs and leaf litter create the moisture retaining detritus in which mesic forest plants grow and thrive.  Note the presence of mosses and a vernal pool in this damp section of forest.
The earliest green leaves in the forest are often those of the Skunk Cabbage (Simplocarpus foetidus).  This member of the arum family gets a head start by growing in the warm waters of a spring seep or in a stream-fed wetland.  Like many native wildflowers of the forest, Skunk Cabbage takes advantage of early-springtime sun to flower and grow prior to the time in late April when deciduous trees grow foliage and cast shade beneath their canopy.
Among the bark of dead and downed trees, the Mourning Cloak butterfly (Nymphalis antiopa) hibernates for the winter.  It emerges to alight on sun-drenched surfaces in late winter and early spring.
Another hibernating forest butterfly that emerges on sunny early-spring days is the Eastern Comma (Polygonia comma), also known as the Hop Merchant.
In a small forest brook, a water strider (Gerridae) chases its shadow using the surface tension of the water to provide buoyancy.  Forests are essential for the protection of headwaters areas where our streams get their start.
Often flooded only in the springtime, fish-free pools of water known as vernal ponds are essential breeding habitat for many forest-dwelling amphibians.  Unfortunately, these ephemeral wetland sites often fall prey to collecting, dumping, filling, and vandalism by motorized and non-motorized off-roaders, sometimes resulting in the elimination of the populations of frogs, toads, and salamanders that use them.
Wood Frogs (Lithobates sylvaticus) emerge from hiding places among downed timber and leaf litter to journey to a nearby vernal pond where they begin calling still more Wood Frogs to the breeding site.
Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the pond dries up in the summertime.  It’s a risky means of reproduction, but it effectively evades the enormous appetites of fish.
When the egg laying is complete, adult Wood Frogs return to the forest and are seldom seen during the rest of the year.
In early spring, Painted Turtles emerge from hideouts in larger forest pools, particularly those in wooded swamps, to bask in sunny locations.
Dead standing trees, often called snags, are essential habitats for many species of forest wildlife.  There is an entire biological process, a micro-ecosystem, involved in the decay of a dead tree.  It includes fungi, bacteria, and various invertebrate animals that reduce wood into the detritus that nourishes and hydrates new forest growth.
Birds like this Red-headed Woodpecker feed on insects found in large snags and nest almost exclusively in them.  Many species of wildlife rely on dead trees, both standing and fallen, during all or part of their lives.

There certainly is more to a forest than the living trees.  If you’re hiking through a grove of timber getting snared in a maze of prickly Multiflora Rose (Rosa multiflora) and seeing little else but maybe a wild ungulate or two, then you’re in a has-been forest.  Logging, firewood collection, fragmentation, and other man-made disturbances inside and near forests take a collective toll on their composition, eventually turning them to mere woodlots.  Go enjoy the forests of the lower Susquehanna valley while you still can.  And remember to do it gently; we’re losing quality as well as quantity right now—so tread softly.

The White-tailed Deity in a woodlot infested by invasive tangles of Multiflora Rose.

A Springtime Quiz

The mild winter has apparently minimized weather-related mortality for the local Green Frog population.  With temperatures in the seventies throughout the lower Susquehanna valley for this first full day of spring, many recently emerged adults could be seen and, on occasion, heard.  Yellow-throated males tested their mating calls—reminding the listener of the sound made by the plucking of a loose banjo string.

Here’s a gathering of Green Frogs seen this afternoon along the edge of a small pond.  How many can you find in this photograph?

If you venture out, keep alert for the migrating birds of late winter and early spring.

Yellow-bellied Sapsuckers are moving through on their way north.  Look for them in mature trees in woodlands, suburbs, and city parks.
The Fox Sparrow (Passerella iliaca), our largest sparrow, is a thrush-like denizen of shrubby forest understories and field edges.  It is an early spring and late autumn transient in the lower Susquehanna valley.
While stopping to rest and feed during their northbound spring journey, Ring-necked Ducks and other diving duck species visit wetlands and flooded timber along the Susquehanna River as well as clear ponds and lakes elsewhere in the watershed.
Eastern Bluebirds are presently migrating through the area.  Some will stay to breed where nest boxes or natural cavities are available in suitable habitat.
Tree Swallows are now arriving.  In open grasslands, pastures, and adjacent to almost any body of water, they will nest in boxes like those placed for bluebirds.
Keep that bird bath clean and fill it with fresh water, the American Robin flights are peaking right now.  Breeding males like this one are starting to sing and defend nesting territories.
Red-winged Blackbirds, like other native blackbirds, are moving through in a fraction of the numbers that were seen in the lower Susquehanna valley during the latter decades of the twentieth century.  They remain a common breeding species in pastures and cattail wetlands.
And of course, keep an eye to the sky.  There are still thousands of Snow Geese in the area.

If you’re staying close to home, be sure to check out the changing appearance of the birds you see nearby.  Some species are losing their drab winter basic plumage and attaining a more colorful summer breeding alternate plumage.

European Starlings are losing their spotted winter (basic) plumage and beginning to display a glossy multicolored set of breeding feathers.
An American Goldfinch in transition from winter (basic) plumage to bright yellow, black, and white summer colors.

So just how many Green Frogs were there in that first photograph?  Here’s the answer.

If you counted seven, you did really well.  Numbers eight and nine are very difficult to discern.

Happy Spring.  For the benefit of everyone’s health, let’s hope that it’s a hot and humid one!

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.

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.
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SOURCES

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