Killdeer

A shorebird that you can see without going to the beach, Killdeer are plovers commonly found locally on lawns, golf courses, athletic fields or parking lots. 

The tawny colored birds—brownish tan on top and white below—have the characteristic round heads, large eyes and short bills of all plovers. Killdeer are slender and lanky with long pointed tails and long wings. The brown face is marked with black and white patches, and the orange rump is conspicuous in flight.

Typically you can see these birds running across the ground in spurts, quickly stopping to check their progress or to see if they startled any insect prey. Near the shore, they inhabit open areas such as sandbars, mud flats and grazed fields.

Killdeer feed primarily on invertebrates such as earthworms, snails, crayfish, grasshoppers, beetles and the larvae of aquatic insects. They also follow farmers' plows for unearthed worms or insect larvae.

The nest of the Killdeer is a shallow depression scratched into the bare ground. Killdeer will add rocks, bits of shell, sticks and trash to the nest for camouflage.

Broken-wing display

Killdeer distract predators from the nest by running away, calling loudly and bobbing up and down. They are one of the best practitioners of the "broken-wing display," an attempt to lure predators away by feigning injury. After the predator is distracted, the Killdeer flies off. The broken-wing display obviously does not prevent cows or horses from stepping on the nest. In cases like these, the Killdeer fluffs itself up, displaying its tail over its head and charging the beast in an attempt to get it to change its path.

The typical brood of four to six eggs is incubated for 22 to 28 days. Chicks can walk as soon as their feathers dry.

Killdeer get their name from the shrill, wailing kill-deer call. Eighteenth-century naturalists used to call them "Chattering Plovers" or "Noisy Plovers."

Subspecies of Red Knot is designated as 'threatened' bird

Tagged 'Rufa' Red Knot; photo by Fish and Wildlife Service

The U.S. Fish and Wildlife Service yesterday designated the "rufa" subspecies of the Red Knot, which frequents the Delaware Bay during its 20,000-mile migration, as a "threatened" species.

Under the federal Endangered Species Act, the threatened status means the bird is likely to become endangered in the foreseeable future. Endangered means the species faces extinction.

The designation does not affect all Red Knots, only those in the rufa subspecies.

Since the 1980s, the population of the robin-sized shorebird has fallen by 75 percent in some key areas, largely due to declines in one of its primary food sources—horseshoe crab eggs in Delaware Bay, a crucial migratory stopover site.

Horseshoe crabs—considered "living fossils" because of their origin 450 million years ago—spawn on the New Jersey and Delaware beaches in May or early June, depending on the moon phase and tides. Each female will produce 80,000 eggs, which are located in dense masses near the front of her shell. She will lay four or five clutches of these eggs, timed to successive tides. The Delaware Bay is the primary spawning grounds of the crab.

Excessive harvesting of horseshoe crabs has meant less food for the rufa Red Knot. The crabs are caught and placed in bait pots to fish for conch and eels.

It is estimated that 90 percent of the entire population of the Red Knot subspecies can be present on the bay in a single day, according to the Cornell Lab of Ornithology. The birds gorge themselves on high-protein crab eggs, and nearly double their weight to prepare for the final leg of their long journey to their Arctic breeding grounds.

Rufa Red Knots usually winter in South America—some as far south as Tierra del Fuego—and fly north to breed in the Canadian Arctic. One bird, banded by biologists in 1995, has become known as Moonbird because he has flown the equivalent of a trip to the moon and back in his 21 years of migrations.

Horseshoe Crab

During their lengthy journey, the rufa subspecies must arrive at the Delaware Bay at the exact the moment when horseshoe crabs have come ashore to lay their eggs. Climate-driven mismatches in migration timing and egg laying affect the birds’ food source.

Officials in New Jersey and Delaware are trying to manage the size of horseshoe crab harvest with the goal of stabilizing the Red Knot population. New Jersey already lists the bird as endangered and has designated the bay as a protected habitat. Law enforcement guards the birds from harassment. Delaware is awaiting guidance from the federal government, the Wilmington News Journal reported today.

Rufa Red Knots also feed on clams and mussels but these are more difficult to extract during the brief time the birds feed in the bay. Crab eggs are soft and more abundant. 

The bird has pencil-thin legs and a slender beak. They are only 9 inches long, about the size of a robin. Their wings extend to 20 inches in flight.

Each May or early June birders gather along the Delaware Bay to watch for the spectacular arrival and feeding of rufa Red Knots. In the Lehigh Valley, Red Knots in general are seen infrequently, sometimes absent for several years at a time, according to Birds of the Lehigh Valley and Vicinity, a publication of the Lehigh Valley Audubon Society.

Lehigh Valley bird sightings for June 16

Male in breeding plumage

This year is turning out to be a real treat for birders in the Lehigh Valley. During the winter, we were thrilled to the first appearance of Snowy Owls since 2002. Now we're getting a glimpse of Black-billed Plovers, a shorebird that was last seen locally in 2004.

Two Black-billed Plovers were seen on June 13 and June 14 on flooded fields along Green Pond Road in Bethlehem Township, Northampton County. The birds are changing to their breeding plumage, which is quite striking. The difference from winter plumage to summer is so great that it's hard to believe that you're looking at the same bird.

The Black-bellied Plover is a large plump-bodied shorebird. It is the largest plover in North America, about 10 to 13 inches tall. In the winter, both sexes look gray overall. But in summer the adult male develops striking black underparts, separated from the spangled gray upper parts by a broad white band. The female is similar, but the black underparts are sometimes mottled. In flight, the birds reveal a striking black "armpit" and white underwings. The beak is black. 

During the summer the birds breed in the Arctic highlands. The pair sighted this week in Green Pond may be a breeding pair far inland and far south from the usual location. During the winter the plovers spend their time along the coasts as far north as Massachusetts and British Columbia.

Non-breeding plumage; the sexes are similar in appearance

Black-bellied Plovers are mostly solitary outside the breeding season. They're wary creatures and quick to give alarm calls, serving as a sentinel for other shorebird species. When disturbed, the plovers often will fly over the water, circle and land again behind the intruder. The Black-bellied Plover is the only American plover that has a hind toe on its foot. However, it's so small that it is difficult to see in the field. The voice is a clear whistled pee-oo-ee.

Their breeding diet is primarily insects. In the winter, they favor small crabs, sandworms and bivalves such as clams and mussels.

The plovers scratch out a nest in the ground and line it with lichen, pebbles, twigs or leaves. The clutch may have as many as five eggs, usually brownish with distinct dark spots. The hatchlings are covered with down but they develop quickly. They are able to walk soon after hatching and feed themselves within one day.

If you plan to visit Green Pond Road to see the Black-bellied Plovers, be careful with traffic. There aren't many cars, but there are no their shoulders along the road. Use a small paved packing area just off the road near the pond. The field are around the bend in the road, according to the updated version of "Birds of the Lehigh Valley and Vicinity," the must-have guidebook for birders in the region.

Green Pond Road is an exceptional site for seeing all kinds of birds, from waterbirds to songbirds to raptors. Local birders have reported 162 different species at Green Pond, according to the Eastern PA Birdline, a sponsor of the Lehigh Valley Audubon Society.

By the way, the Snowy Owls have returned to their summer breeding grounds in the Arctic. For details on their wintertime appearance in the Lehigh Valley, visit our blog postings here, here, here and here.

Below are the rest of the Lehigh Valley bird sightings for the period ended June 16. The list was compiled by The Bird House through individual reports to the American Birding Association News website and local observances.

Bethlehem, Northampton County
Peregrine Falcon, 3 hatchlings at nest on June 11.

Bethlehem, Northampton County
(Center City)
House Finch, 8 on June 16.
Common Grackle, 5 on June 16 (including 3 adolescents).
Mourning Dove, 2 on June 16.
Northern Cardinal, 1 male on June 15.
House Sparrow, 4 on June 16.

Haafsville, Lehigh County
Great Blue Heron, 1 on June 13.