Birds : Spring tease
Martha's Vineyard is a fickle place for birding at this time of year. Hardly feast or famine, it is more apt to range between a reduced calorie diet and what at times seems like starvation. Even though bird migration is clearly under way, and ospreys have returned to enliven our skies and robins sing at dawn and dusk, it still feels like winter has her icy grip on the situation.
How quickly things will change when the sun finally shows itself. Despite this whining - the opposite of irrational exuberance, if you will - the birding is improving and can be expected to virtually explode in the weeks ahead, especially when compared to what has been going on during the past month. Birds are on the move and by the end of next week land birds will be much more obvious.
Photo by E. Vernon Laux
Diurnal raptors including the aforementioned ospreys as well as red-tailed hawks, Cooper's hawks, northern harriers, and turkey vultures are all very obvious of late. These species all breed on Martha's Vineyard and the sights and sounds of their courting are hard to miss when the weather is not miserable. They know what time it is, even though the temperatures have refused to cooperate.
Red-tailed hawks are engaged in aerial courtship displays. Courting pairs engage in leg-dangling, talon- dragging descending flights, and then rocket skyward again to perform spectacular loop de loops. These impressive diving flight displays have been a common sight when the weather has been good during the past week.
The moth-like, exaggerated deep wing beat flights of displaying Cooper's hawks have also been a regular feature all over Martha's Vineyard. I was fortunate to witness this behavior three times this past week. This behavior and manner of flight gives these fast flying predators, which specialize in ambushing other birds, an entirely different look from what one is used to. Even the turkey vultures have been performing some rather neat acrobatics overhead of late, obviously not something they do whilst looking for road kill.
Northern harriers - raptors that specialize in capturing rodents with their very long legs in slow speed flight over open fields, dunes, and marshes -enjoy a healthy breeding population on the Vineyard and are also engaging in their special courtship flights. Both the male and female engage in these flight displays. The individual performing the flight will climb vertically until it is about to stall, then it flips its body upside down and inverted it falls back towards earth. Regaining flight control it gathers speed and as it gains speed it pulls back, climbs again, and repeats the whole process for the benefit of its watching partner. It is amazing to watch the bird reach the top of its arc and flip over in the blink of an eye.