By ALLAN KEITH
Between now and mid-April, occasional migrating small birds arrive on the Island exceptionally early.
Here is how this phenomenon is believed to occur. As they are flying north across the Gulf of Mexico or are airborne over the southern Gulf states, a fast-moving weather system almost literally scoops the birds up and takes them north along the Atlantic coast, often just offshore. Not being able to land at sea, they are carried to the northeastern part of the country which lies much further east than, say, the east coast of Florida.
Thus they arrive here tired and hungry and therefore often seek out feeding stations for water, suet and bird seed.
A couple years ago, two prothonotary warblers, a Kentucky warbler and two or three indigo buntings appeared here in the last few days of March. At other times, summer tanagers, blue grosbeaks, rose-breasted grosbeaks, a northern parula warbler and once even a ruby-throated hummingbird got here about the same time.
Unfortunately, once here, conditions are less than ideal for these birds. Seed eaters like the buntings and grosbeaks can usually find enough to eat, but since the leaves are not out yet and therefore insects are few, insectivorous species such as warblers have a hard time.
No one knows exactly what these waifs do. Some may turn around and fly back south, but we do know that most of them do not remain here long and many probably head to the mainland where leaf emergence is earlier than out here, especially inland away from the coast.
The lesson to take away from all this is that it is still too early to take down your winter bird feeder and not too early to put out a hummingbird feeder and bird bath for water. The list of possible species that could appear early is a long one, so keep a close eye on what appears at your feeder and call the bird hot line if you find anything that looks unusual.
Signs of early migration are everywhere. The numbers of sea ducks such as common eiders and the three species of scoters in the ocean off Gay Head have dropped noticeably since February. At least 5,000 of the eiders are still here, but that is only about a third as many as a month ago.
As already reported, the first osprey arrived nearly a week earlier than ever reported before, on March 9, and others are scattered about Island ponds. Out on the Matakeeset sand flats at the very southwest corner of Katama Bay at low tide, the number of black-bellied plovers has doubled to more than 20 in the last three weeks, the number of dunlins has increased to more than 75 from only 25 or so, there are now three pairs of American oystercatchers in the same area, and the first piping plovers of the season were there March 23. A single killdeer in the field at Keith Farm on March 2 could have been a wintering bird, but there are now three there, indicating recent arrivals. Robins are on patches of grass and open fields Islandwide.
Numbers of long-tailed ducks, hooded mergansers, buffleheads, harlequin ducks and common goldeneyes are dropping as these birds head north to their breeding grounds. Large numbers of blackbirds are now here as everyone has surely noticed. The first northbound gannets I have seen this year were off the south beach at Katama on March 25. A female American kestrel, a bird that formerly nested here in numbers but is now uncommon even as a migrant, was first found at Katama Airport on March 23. On close inspection, she was seen to have an aluminum fish and wildlife service band on her right leg.
In the category of winter birds still lingering, most feeders still have a few white-throated sparrows and dark-eyed juncos, some of which will probably stay until late April or early May. Lanny McDowell has got some fine photographs of a northern shrike that is still present at Katama Farm and Katama Airport. The Eurasian widgeon is still hanging out with black ducks in the pond just east of the north end of Fuller street in Edgartown. Great cormorants are still around in numbers, many now in striking breeding plumage with white flank spots and white chins. Flocks of up to 10 or so northern flickers are being seen on up-Island fields hunting for ants and other insects; they will break up into pairs shortly and spread out through the woods. The flock of 10 field sparrows and one lone chipping sparrow that have been at my feeder all winter are still sticking together but will also pair up and disperse before long.
The swallow-tailed kite first seen on March 10 by William Marks and which was found dead on March 14 by Jeff Komarinetz proves to be the second earliest ever known in spring for Massachusetts, the earliest being on March 9. It will be taken to the Museum of Comparative Zoology at Harvard shortly, where it will be added to the permanent collection. It appears to be only the third specimen known for the state as well. Just a reminder: please let me know of any dead bird in good condition. Put it in a plastic bag in your freezer. I will pick it up and see that it gets to the museum which is very glad to have new specimens.
The first swallows are due here any day now, and a Web site tracking the northbound migration of ruby-throated hummingbirds (hummingbirds.net) shows them already in Tennessee and eastern Virginia from their winter home on the Yucatan Peninsula.
Reports to the bird hot line have been sparse in the last week or so but the birds are out there for those who look. Laurie Walker, Katherine Colon, and Carol Dell birded up-Island on March 22 and found some American coot at a little pond in Chilmark, purple sandpipers at Squibnocket Beach, horned grebes in Menemsha Pond, and long-tailed ducks at Lobsterville, just to name a few. Perhaps the most interesting, they also found a probable early arrival female Baltimore oriole at the Bank of Martha’s Vineyard office in Chilmark and got three good photos.
Keep on the lookout for more early arrivals after the warm weather and southerly winds this past mid-week, and be sure to call the hot line at 508-627-4922 with your reports.