Birds : Spring fling: Birding is rollicking
The birding has been fantastic this past week. Anyone who is still ten-toes-up will have noticed the remarkable and unseasonable spring weather. This past Sunday, April 26, would have been a really nice day in August. The record-breaking heat has accelerated the arrival of many species. Arrival dates during the past 50 years clearly show that birds are returning north earlier. When temperatures in the 80s occur here in late April accompanied by a strong southwesterly wind, the recipe for bird migrants is complete.
Historically, the first week of May is the time that many species of birds return north to summer haunts in New England after spending the winter in various neo-tropical locations. The species' inherited biological clocks and their hormonal balances triggered by photoperiod and ambient temperatures compel the birds to migrate. Displaying remarkable navigational skills, sheer physical toughness, and incredible powers of flight, the birds arrive in seemingly miraculous fashion at precisely the right time.
Year after year, within a scant few days, the birds, after traveling many thousands of miles, find their way back to the exact location where they were a year ago. For human observers this was once hard to believe and harder to prove. Then through capturing and banding of birds, it became proven that they perform these incredible annual migrations.
Migrant birds attempt to avoid the strong frontal systems that buffet the U.S. in spring. However, inevitably they encounter some unexpected weather. For first-time northbound migrants, those who have only inherited information but no real world experience, there is much to learn and avoid. The powerful fronts and the edge between high and low pressure systems can wreak havoc on migrant birds and often ground them or transport airborne birds to a place they did not plan on visiting.
It is the fact that birds on the move can have their courses altered significantly by storms that generates the excitement and thrill of the surprising, as birders hope that some stray waif from elsewhere on the planet may descend onto their local patch. It is the discovery of what might have flown in overnight and of not knowing what one might find that appeals to many long time birders.
A quick summary of April highlights is in order. The month provided some exciting southern overshoots and much needed relief after the winter months. Summer tanagers appeared in Edgartown with at least four individuals reported. White-eyed vireos, a southern species that occasionally makes it to Martha's Vineyard, were reported frequently. At one point, two males were singing simultaneously at the Head of the Lagoon. Lots of indigo buntings, rose-breasted grosbeaks, a few Baltimore orioles, and a couple of ruby-throated hummingbirds rounded out the month. While far from all the birds sighted, these represent some of the highlights for April almost finished.