The sky pointers are back. Have you seen male common grackles walking or standing with their bills pointed up to the sky? This threat display is one of my favorite sights in the spring. I had to wait this year; the arrival of common grackles was late this spring but they are now abundant everywhere.

With a sleek, glossy blackish plumage and yellow eyes, the adult common grackle is a striking bird. The birds are about 12 inches long, including the long tail. It is not easy to tell males from females, although males, in favorable light, have a glossy purple head and breast. The female is usually slightly smaller than the male. In flight, grackles hold their tails in a V, like the keel of a boat.

In northern New England, we have the subspecies of common grackle called the bronzed grackle. This form is named for the bronze cast to its feathers. Two more subspecies, nesting from southern New England to Florida, are collectively referred to as purple grackles. They lack the bronze undertones of our grackles and are mostly a deep purple. Some have a distinctive green “backpack.” The bronzed grackle and the purple grackle were once considered separate species.

Despite their sleek appearance, grackles will win no contests for the beauty of their songs. Both males and females sing the same harsh, squeaky song that some ornithologists interpret as “squ-eek,” “readle-eak” or “scuda-leek.” Some people think the song sounds like the opening of a gate with a rusty hinge. These birds also give a characteristic raspy “chack” call, often in flight.

Males sing more frequently than females and male song rates are highest early in the breeding season. Each individual sings a single song but there is a lot of variation among individuals. The songs therefore seem to be useful for individual identification.

This species is highly gregarious; if you see one, you will probably see 10. Except for females incubating eggs, grackles roost together at night in noisy roosts, sometimes more than 100 birds in one roost.

To attract a female, a male performs the song spread display. The male will raise the feathers around his neck, drop his wings and sing his song for a prospective mate.

Pairs form soon after the birds arrive, so keep an eye out for the song spread behavior. The female builds the nest, usually well above the ground in a conifer. The male guards the female throughout the nest construction process. Once the nest is complete, the female will perform a wing-quivering display, a signal that she is ready to mate.

The male aggressively keeps other males away from his mate. The sky pointing display is used to threaten other males. The vertical raising of the bill tells other males that they are not welcome. The display usually results in displacement of the intruding male.

Common grackles may nest alone but more often in colonies of 10 or more pairs in tall trees, especially evergreens. Sometimes nests are made in freshwater marshes, old buildings or even the lower parts of Osprey nests. The nest is made of twigs and grass stems. Most nests contain five or six eggs, which the female incubates for about 14 days before hatching. The newly hatched birds are ready for their first flight in 14 to 16 days. Juveniles are dark brown with brown eyes.

Some common grackles attain impressive ages. The oldest known common grackle was banded in Michigan, and recaptured 20 years and 11 months later in Illinois. One in Minnesota lived to be at least 17 years, while a New Jersey bird lived to be at least 16 years, 1 month. The average life span is likely much less than these extremes.

Herb Wilson teaches ornithology and other biology courses at Colby College. He welcomes reader comments and questions at:

whwilson@colby.edu