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.

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.