Birds

Peak week

By E. Vernon Laux - September 28, 2006

In far northern and inland Maine, it is the peak week for brilliant foliage, while on the Vineyard, the end of this month represents the absolute peak of the fall bird migration. Birds of many species are currently at their highest population levels of the year, and they are on the move.

There is a lot to see every day, but on days following the passage of a cold front, it can de downright spectacular birding anywhere on the Island. On these days the shorelines and ridges along the north side of the Island turn into avian highways for migrants making their way south for the winter.

Many species are intermingled in the mix of migrating species. Insectivorous birds like kingbirds, flycatchers, and warblers are a bit late on their way south, while seed-eating sparrows, grosbeaks, and finches are a little early. They are all moving, and on any given day lots of birds may be encountered. Some days there will be overwhelming numbers of certain more common species while uncommon to rare birds are hard to find because of the large number of birds to look at.

This is a wonderful problem to have; it illustrates the magic and wonder that is bird migration. A big flight day when you can literally see tens of thousands of birds climbing into the sky as they prepare to make the jump-off flight back to the mainland provides a very exciting day in the field and memories of what is possible.

Right now, coincident with the major movement of land birds, is the peak of the small falcon migration. The merlin, a compact, powerfully built, speedy bird hunter, reaches its peak of migration this week. These winged little rockets are a daily sight, usually in multiples as they follow the songbirds south along the coastline. Favored spots to see these falcons include the Gay Head Cliffs, Wasque, either the north or south shore, and near any promontory. All will hold marauding merlins over the next couple of weeks.

The larger and much more powerful peregrine falcon is also passing by in migration. With proportionally longer wings than merlins, they are also superb aerialists who capture large flying birds, including a variety of ducks and gulls. They typically peak a couple of weeks later than merlins and their migration movements coincide not only with land birds but also with waterfowl.

Virtually all species of waterfowl, including sea ducks that pass by or remain for the winter and a wide variety of sea birds, are also engaged in migration. On the waters surrounding the Island over the next few weeks, several species of large sea ducks, called scoters and common eiders, will arrive in the hundreds of thousands. These massive flocks of ducks are impressive as they arrive, flying in groups so large that they often obscure the surface of the water from a distance. The birds remember, being warm-blooded homoeothermic vertebrates, from previous experience about the bounty of the area's mussel beds, the birds' primary source of food.

Tree swallows. Photo by E. Vernon Laux
This flock of tree swallows was photographed on the wires along Moshup Trail in Aquinnah. These birds congregate in flocks sometimes numbering 20,000 birds at favored spots with lots of bayberries, before proceeding south. They are ubiquitous on the Vineyard right now. Photo by E. Vernon Laux
No place on the continent has as spectacular a concentration during October through December, and it is just another reason to come birding here or take up the hobby. The masses of eiders and scoters off Wasque in Edgartown, off Cape Pogue, in the middle of Vineyard Sound and from Lucy Vincent Beach in Chilmark stretching west around Squibnocket Point to the Gay Head Cliffs and beyond are hard to count, but most impressive.

Flocks of tree swallows, small insectivorous birds, are massing along beach areas and areas with lots of bayberry shrubs. These tiny birds are hard to miss as they mass in huge flocks before departing south. This species changes its diet at this season, changing from insects which they will still readily eat to bayberries when it is cooler and there are no insects to catch.

The birds are able to digest the hard, waxy berries. They ingest the whole berry, and as they fly south they spread them along the entire Eastern Seaboard. They are largely responsible for spreading the seeds far and wide in a symbiotic relationship. Yellow-rumped warblers also are able digest these berries and depend on them to survive the hostile winter months at this latitude.

The season is shifting rapidly now in this first full week of autumn. Flocks of birds ranging from cedar waxwings to blackbirds to bobolinks are on the move. On clear nights with cool winds, the night sky is alive with flying nocturnal migrants. It is a treat, a throwback to a simpler time, to stand outside gazing into the night sky listening to the flight call notes of various species passing overhead, unseen but heard. Life is winging its way south while we sleep, mysterious on so many levels to fellow bipedal creatures that are restricted to terra firma without the aid of machines.

Until next week - keep your eyes to the sky!

To contribute news about birding activities or sightings, call The Times Birdline, 508-693-6100, extension 33, or e-mail birds@mvtimes.com.