It was a pretty good season for beach nesting birds this year. With the season pretty much over now, the results are in. The Vineyard set a new record for breeding piping plovers at 70 pairs. This is an amazing increase over the dozen or so pairs that were here in the late 1980s, when the species was first listed under the Federal and State Endangered Species Acts. The increase is due to the tremendous efforts of many people over the past approximately 30 years.
Careful observations are necessary to find plover nests, as the eggs are well camouflaged against the sandy, shelly and stoney background of our beaches. It is the behavior of the adults that really shows where the nests are. Once the nests are found, they are monitored regularly to determine the outcome of each nest.
Those 70 nests fledged 71 chicks. While this is a lot of fledglings, it is not good enough. Scientific studies have shown that an average of approximately 1.25 chicks per pair must fledge to maintain a stable population. For some reason, the Vineyard always tends to be below this threshold of productivity. In many years the Vineyard’s productivity has been the lowest of any region in the state. The primary source of egg loss was due to predation by crows and skunks. The primary source of chick loss was due to predation by crows and gulls. Disturbances by dogs that were too close to the nests were prevalent. When plovers are disturbed in this manner the opportunistic predators are more likely to do their dastardly deeds.
American oystercatchers are a showy species that benefit from the plover protection efforts. This year there were 41 breeding pairs and they fledged 46 chicks. They too have increased greatly over the years. Allan Keith found the first modern oystercatcher nest in Massachusetts on Cape Pogue in 1968.
Terns also benefit from plover protection. Forty-two pairs of roseate terns nested on Norton Point Beach and Little Beach this summer. These two Edgartown sites are important as one of the recovery goals of this federally endangered species is to establish new colony sites to supplement the two primary nesting sites in Buzzards Bay and Long Island Sound.
Another tremendously popular large tern is the black skimmer. Almost everyone marvels at the sight of these graceful birds, even the curious non-birders that stop by to ask what we are looking at. This southern species has been nesting on the Vineyard for several years now, and there were eight breeding pairs this year. Five of these pairs were on Little Beach and three were on Norton Point Beach.
There were 194 breeding pairs of common terns on the Island this summer. Most of them were on Norton Point and Little Beach, while 36 pairs nested at two salt marsh sites in Sengekontacket Pond — their ancestors traditionally nested on State Beach near the big bridge.
Least terns are the most common tern on the Island. (Aren’t common names fun? Common terns are not the most common tern!) There were 499 pairs of these smallest of our nesting terns this summer.
Four organizations are responsible for monitoring plovers, oystercatchers and terns on the Vineyard, here listed in alphabetical order: BiodiversityWorks, Martha’s Vineyard Land Bank, Massachusetts Audubon Society and The Trustees of Reservations. Thank you to each of them for a tremendous effort this summer!
Bird Sightings
Some different shorebirds are showing up, adding to the already large diversity of the regulars. Most notable of these was identified via a photograph taken by Michael Ditchfield of three dowitchers on August 23. While both species of dowitchers have long bills, the bill of one of the birds in the photo is about 30 per cent longer than the other (the third dowitcher’s bill is partially concealed as it is probing the shallow water). Lanny McDowell and Matt Pelikan both identified it as a long-billed dowitcher, an unusual species on the Vineyard. Long-billeds are typically here sometime between late August and November, while short-billeds are found in flocks from July to September.
There are two other different shorebirds this week. Winnie and Fred Spar observed a lesser yellowlegs on Norton Point on August 17, and Michael Ditchfield spotted one at Sengekontacket Pond on August 20. These birds are distinguished from the greater yellowlegs by their shorter bill length, which is about as long as their head. Jeff Bernier found the third different shorebird, a Forster’s tern, in Eel Pond north of Little Beach on August 20. This species is distinguished from other terns by its black eye/ear patch on an otherwise white head. Both species are expected at this time of the year.
Other highlights from Winnie and Fred Spar include two red knots, an immature black skimmer and greater yellowlegs. And Michael Ditchfield also spotted three snowy egrets at Sengekontacket Pond.
Steve Allen and Al Sgroi lead a birders walk on Thursday mornings, and their highlights include Felix Neck’s first northern mockingbird and Carolina wren of the season, as well as oystercatchers, greater yellowlegs, willet, ruddy turnstone and both black-bellied and semipalmated plovers.
Chris Daly reports a great-crested flycatcher in the oak canopy at Nomans Watch in Aquinnah on August 23. He also has been hearing a Baltimore oriole, which is unusual for that part of Aquinnah.
Susan Straight called in to report that she found two red-tailed hawks chasing each other and screaming bloody murder in a field near the Grey Barn on August 10. Most likely the trailing bird was a juvenile still learning to hunt, so it was chasing one of its parents begging for food. Gus Ben David describes this as typical raptor behavior at this time of the year.
I was visiting the Maine coast last week, where my highlights were seven black guillemots — two adults and five full-grown youngsters, both solitary and spotted sandpipers, Bonaparte’s gulls, lots of red-breasted nuthatches and five species of warblers (redstart, black-throated green, blackburnian, Cape May and black-and-white). While these songbirds nest in Maine’s spruce trees, the southward migration of songbirds is about to begin. The Massachusetts Audubon Society reports sightings of two western species of hummingbirds, a northern waterthrush and a hooded warbler elsewhere in Massachusetts this past week.
There are lots of birds around, so please get out looking for them, and be sure to report your bird sightings to birds@mvgazette.com.
Robert Culbert leads Saturday morning guided birding tours and is an ecological consultant living in Vineyard Haven.
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