VT Weekly Bird Notes: Nighthawk Migration

Common Nighthawk by destabee

I hear a faint nasal “peent” noise above the din of cricket calls along the Connecticut River. In the fading evening light a small flock of five common nighthawks appears, flying erratically down the river chasing insects and moving slowly southward. It’s August and we are in the thick of nighthawk migration. Unfortunately, it may not be the migration spectacle that it once was.

Tom Gagnon has been watching the nighthawk migration along the Connecticut River near Springfield each evening from late August through early September for nearly 30 years. He saw an average 3,680 birds a year during the first 22 years of watching the migration. The lowest count came in 2000 when he counted just 1,340 and the annual count has since averaged just 1,600 birds.

The Vermont Breeding Bird Atlas is showing a drastic decline in breeding nighthawks in Vermont. The first atlas in the 1970s found them potentially nesting in 35 areas. The current atlas finds them in just eight areas, with no confirmed nests. The story is much the same throughout the entire Northeast.

While ornithologists don’t know what is causing this drastic population decline, there are several good hypotheses. Sometime around 1900 nighthawks began to nest on gravel rooftops in urban areas. They have almost disappeared from many of these cities. This may be due to rising populations of crows or other predators such as cats, rats and raccoons. Many roof tops are no longer gravel, but are rubber. Pesticide use could have reduced insect populations or poison nighthawks. Natural nesting habitat has been greatly reduced in many areas. And finally, their migration takes them as far as Argentina. There could be a wide variety of problems they encounter on migration and in the winter grounds of South America. What is clear is that more research is sorely needed.

New Hampshire Audubon is trying to help nesting nighthawks in urban areas. They are laying patches of pea sized gravel on flat roof tops that are covered large stone or rubber in hopes of providing good nest sites once again. Hopefully research and management like this will help bring back the nighthawk to New England.

Nighthawks are making their move now. On August 27 seven were seen on the Connecticut River near Norwich. Over 30 were seen on the evening of August 28 at the mouth of the Ompompanoosuc River in Thetford.

Other Bird Highlights

Shorebirds continue to flood Vermont from the north. A whimbrel was seen just off the Vermont shore by a birder traveling on the Charlotte Ferry on August 25. Dead Creek Wildlife Management Area continues to be the hotspot. Semipalmated plovers, killdeer, greater and lesser yellowlegs, solitary sandpipers, semipalmated sandpipers, least sandpipers and pectoral sandpipers have been seen regularly the past several weeks. Additional species this week included black-bellied plover, white-rumped sandpiper and a western sandpiper. Five short-billed dowitchers were found at Holcomb Slang on August 25.

Other highlights at Dead Creek included an early snow goose on the 22^nd, three northern shovelers on the 20^th and over 70 great blue herons. A possible Eurasian wigeon was seen by several birders along Dead Creek on August 18. Red-necked phalaropes were seen at Dead Creek on August 18 and Grand Isle on 25th.

A jaeger was observed off Grand Isle as well as two juvenile parasitic jaegers at Charlotte Town Beach on August 26. Twenty black terns were observed at Missisquoi National Wildlife Refuge on the 21st.

Tree Swallows are massing for migration. On August 24 there were over 400 at Herrick's Cove in Rockingham.

You can explore all the birds reported last week in Vermont and add your own sightings at www.ebird.org/vins.

Kent McFarland

What's in a Name?

Pectoral Sandpiper by Henry McLin

Birdwatchers are keenly aware of the challenges in identifying difficult groups of birds. There are those confusing wood-warblers that don't sit still and those little brown sparrows that all look alike, but shorebirds? They just seem impossible! Not only are they small, drab birds, but they spend very little time in Vermont. When they are here, they are not in bright, fresh breeding plumage.

One of the first shorebirds I could reliably identify was the Pectoral Sandpiper. Pectorals pass through Vermont in small numbers, but they are a regular visitor to mudflats in the Champlain Valley each fall. You can pick them out from the other "peeps" (small indistinct shorebirds) by their medium size and barring on the chest that stops half way down their breast in an abrupt line. Their favorite foraging locations tend to be in shallower, wet areas near vegetation.

Like most shorebirds, Pectoral Sandpipers breed in the arctic tundra of North America and Siberia. After their short breeding season, birds in Siberia migrate east over the Bering Sea and then south to their wintering grounds in the pampas of South America. Some individuals journey over 18,600 miles round-trip, rivaling the longest bird migrants in the world.

Such a long-distance flier certainly must have strong pectoral muscles, but this is not how they get their name. Rather, it is for the inflatable air sacs on the throat that males use to court females and defend their territory. They fly over females producing a low, hooting sound; a distinctive song in the summer arctic.

Male territories are spaced widely apart, each bird defending 10-15 acres. A breeding male will pursue any female that enters its territory. Although studies have not been done to determine how many females a male successfully mates with, it is thought that they breed with more than one female (a polygynous mating system). Females incubate, brood, and raise chicks without any help from the males. In fact, the males leave the arctic breeding grounds before the eggs even hatch.

Several migrant Pectoral Sandpipers have been seen regularly at the Dead Creek Brilyea Access since July 25, and more are sure to follow with the ongoing tide of arctic migrants. Other recent shorebird sightings include Lesser and Greater Yellowlegs, and Spotted, Solitary, Semipalmated, Least, and White-rumped Sandpipers. More unusual sightings have included Stilt and Western Sandpipers and Red-necked Phalarope.

You can explore all the birds reported last week in Vermont and add your own sightings at www.ebird.org/vins.

-Julie Hart
Conservation Biologist

Renowned Ornithologists to Visit Hog Island, Maine, in September

HOG ISLAND, Bremen, Maine - When naturalist and author Scott Weidensaul calls out, "Gannet at 9 o'clock!" birders rush eagerly to the side of the boat, field glasses glued to their eyes. Everyone wants a good look at the graceful white seabird with the long, elegant black-tipped wings, and Weidensaul and his colleagues do everything in their power to make that possible.

Some of the world's finest naturalists are drawn every summer to Maine Audubon's Hog Island in Bremen, and this year is no exception. Earlier this summer, famed author and naturalist Scott Weidensaul led the Field Ornithology Session along with other nationally known birders and authors Kenn and Kim Kaufman, Sara Morris, Jeff Wells, Greg Budney, and Steve Kress. "The richness of the Hog Island experience lures renowned naturalists like Weidensaul and Kaufman to our shores," says Maine Audubon Center Director Seth Benz, "and they, in turn, attract the interest of experienced and novice birders alike."

Weidensaul is returning to Maine Audubon's Hog Island for a special week-long program on Bird Migration and Conservation September 9-15. A Pulitzer-prize finalist author, Weidensaul released his most recent work, Return to Wild America ­ A Yearlong Search for the Continent's Natural Soul, in 2005. In it, he retraces the legendary epic journey of artist and field guide author Roger Tory Peterson and British naturalist James Fisher: 100 days of trekking over 30,000 miles around North America, recounted in their classic, Wild America. Weidensaul shares with his readers the changes he has noted in this continent's natural landscape in the half century since the publication of Wild America.

Other instructors joining Weidensaul for the September session include Jeff Wells of Boreal Songbird Initiative, Peter Vickery of Center for Ecological Research, Alicia Craig of American Bird Conservancy, and Karin Eberhart of Birdlife International.

Weidensaul's September visit to Maine will focus on his discoveries at Maine Audubon's Hog Island. Participants will also travel to Monhegan as part of the session. A few places still remain for participants interested in the September 9-15 session. To register, call (888) 325-5261, ext. 215, or log on to www.maineaudubon.org for more information.

About Scott Weidensaul:

Weidensaul has written more than two dozen books on natural history, including his widely acclaimed Living on the Wind: Across the Hemisphere with Migratory Birds (North Point 1999), which was one of three finalists for the Pulitzer Prize for general nonfiction. His writing has appeared in dozens of publications, including Smithsonian, the New York Times, Nature Conservancy, National Wildlife and Audubon, among many others. He lectures widely on conservation and nature.

In addition to writing about wildlife, Weidensaul is an active field researcher whose work focuses on bird migration. Besides banding hawks each fall (something he's done for almost 20 years), he directs a major effort to study the movements of northern saw-whet owls, one of the smallest and least-understood raptors in North America. Most recently, he has joined a continental effort to understand the rapid evolution, by several species of western hummingbirds, of a new migratory route and wintering range in the East.

About Hog Island Audubon Center:

Accessible only by boat, Hog Island is a 330-acre island in midcoast Maine's beautiful Muscongus Bay. It's part of Todd Audubon Sanctuary. Since 1936, it has been home to Audubon camp for adults, educators, and young people, with sessions led by some of the most respected naturalists and environmental educators in the nation.

Vermont's Ethereal State Bird

Hermit Thrush, John D. Ingram 2001

As flocks of shorebirds gather at Vermont’s wetlands to herald the onset of fall migration, some late nesters are still tending to eggs or chicks. Quite appropriately, among the “stragglers” reported by birders this week were Hermit Thrushes.

You might already know that in Vermont, the Hermit Thrush is no ordinary bird. In 1941 it was declared the official Vermont State Bird. They are one of the most widely distributed forest-nesting migratory songbirds, and Vermont is no exception: they are found in all 14 counties.

The Hermit Thrush is distinguishable from other thrushes by its reddish tail that it frequently flicks upward. Both males and females share this feature, as well as all other plumage characteristics: olive-gray above, black spots on the breast, a white belly, and a white eye ring. Perhaps the Hermit Thrush’s most notable quality is its song, arguably one of the most beautiful in Vermont’s forests. It begins with a single low whistle, and then ascends in a swirling, flutelike spiral. Some describe it as “ethereal.”

From Alaska to Newfoundland, and in the western and northeastern U.S., the Hermit Thrush breeds in deciduous and coniferous forests. In the winter it inhabits densely vegetated forests and thickets throughout the southern U.S. and Central America as far south as Guatemala. During the breeding season they forage much like their relative the American Robin, hopping on the ground and lifting up leaves in search of insects. In the winter their diet switches to fruit.

In Vermont and elsewhere in the east, Hermit Thrushes nest on the ground. Their bright sky-blue eggs, typical of the thrush family, would stand out like a sore thumb if the nests were not so skillfully placed under the shelter of small plants.
Although Hermit Thrushes prefer large forest tracts, they often choose to nest near the edge of small openings within the forest, such as a gap caused by wind or fire, an overgrown logging road, a small pond, or even human dwellings. Re-growth of forests has been favorable for the Hermit Thrush. It will likely continue to make itself at home here in Vermont, where we stake a claim to this celestial singer.

In other birding news, the greatest highlight this week is a state first record: a pair of Sandhill Cranes nested successfully in the Champlain Valley, producing one fledgling. Other reports included more migrants: a Whimbrel flying overhead in Westmore, and many shorebirds at Dead Creek: Semipalmated Plovers; Least, Pectoral, and Semipalmated Sandpipers; and Greater and Lesser Yellowlegs. A White-rumped Sandpiper was seen in Grande Isle, a Great Egret was reported at Retreat Meadows in Brattleboro, and a flock of 1500 – 2000 Tree Swallows was seen in Orwell.

Rosalind Renfrew