Birds : Welcome back, ospreys

By E. Vernon Laux
Published: March 18, 2010

March is a month of extremes and change in the natural world. The weather outside was frightful this past weekend with a determined northeaster bringing prolonged strong winds and prodigious rainfall. While I'm no genius at reading weather maps, I do have a lot of practice, and while writing this on the afternoon of March 15, during the last blast of the northeaster, my guess is that by the time you read this on March 18, one or more ospreys will have returned to the Island. By the end of this coming weekend there should be male birds back on many nest poles that were successful last season.

The arrival of osprey - large, powerful sea hawks - heralds the arrival of spring on the Island. Their advance guard will be staking claim to favored nest sites this week. Click on photo to enlarge. Photo by E. Vernon Laux

As of this writing, none have been reported from the Vineyard. At least three reports have come in this past week, but alas the observers were only 75 to 98 percent sure that they had seen an osprey fly by. None were 100 percent sure that they had seen the season's first osprey. At any rate, with relatively nice weather predicted for this coming weekend, there is little doubt that a few individuals representing the Island's favorite bird, the Vineyard harbinger of spring, will be back.

Another Island crowd pleaser, that most colorful and noisy of shorebirds, the American oystercatcher has also returned this past week. More are on the way. These birds are something to see. Relatively tame on the Vineyard, they often allow great views. The bright orange, knife-like beak contrasting against their black and white plumage along with the amazing black pupil, yellow iris and bright orange (same color as the beak) orbital ring (bare skin around the eye) are unforgettable.

No matter what the weather does now, birds are on the move. Migration is more than a trickle, especially for loons, grebes, northern gannets, sea ducks and gulls. The waters surrounding the Vineyard and sky just above them are crammed with birds. Try an early morning birding session using binoculars off the south shore and be amazed at the steady progression of migrant birds heading east.

In March, fabulous weather for a day or two is often followed by a vicious blast from a prolonged northeaster caused by a rapidly moving frontal system coming across the continent and engaging with the Atlantic Ocean. While the muddy roads and often raw temperatures remind one of winter, the increasing length of day and power of the sun suggest that summer is approaching, if grudgingly.

Woodpeckers are particularly noticeable at this time of year. Not only are they very active and noisy, they are easy to see in the leafless trees. Add to this their peculiar specialized form of communication, drumming, and these wild and crazy birds can create not only fans but detractors as well.

Drumming is used to declare territorial rights and to advertise for a mate. Because of the low wave frequency caused by drumming, the sound can be heard over far greater distances than vocalizations. Male and female woodpeckers of some species perform ritualized duet drumming during pair formation.

If you go for a walk in the woods or your neighborhood in the morning, keep your ears open for the sounds of drumming because Island species are all setting up territories. Listen to the cadence and amplitude then try to find the bird with binoculars. With a little practice you will be able to identify different species.

Woodpeckers have many unique physiological adaptations that allow them to drum without caving in their heads, which house the woodpecker brain. It sounds like they are literally banging their brains out, and without these physiological attributes that is what would happen. Woodpecker heads are unlike those of other birds.

Their skull has a double ossified layer of bone, reinforced double thickness if you will. There are larger areas of cerebral spinal space in the front and back of the head that are full of spinal fluid acting as shock absorbers to prevent concussions. Even their nostrils have special adaptations to keep them from inhaling sawdust.

Bird song continues to increase. Eastern bluebirds have been heard from Chilmark to Edgartown. This weekend should see an influx of bird species including killdeer, tree swallows, eastern phoebes, many more blackbirds and American robins, and perhaps singing pine warblers. There will also probably be a few surprises in the form of birds with a more southerly range that occasionally overshoot their destination in the spring.

Keep an eye out on your neighborhood osprey pole and write down the date you first see an osprey on it. It seems that the birds arrive back to their specific poles with an uncanny knack for getting there at the same time, within a day or two, each year. At any rate it will be a great time to get outside and enjoy the birds, gardening, or whatever you like to do.

Until next time - keep your eyes to the sky.