Hawks vs. Parrots

A remarkable demonstration of the monk parakeet's defensive "sentinel system" occurred on Saturday, when a red-tailed hawk flew within visual range of the Brooklyn College parrots.

Within seconds after a sharp-eyed "lookout" sounded the general alarm call, all 25 or so of the foraging birds rose in flight. A smaller group of 12, perching in a nearby tree, joined the flocking parrots, and within less than 10 seconds, all had found safe harbor in nests housed in three of the large field lights.

The hawk, still visible in the Eastern sky, continued to cruise several hundred feet above the ground on its course, which I reckon was a straight line between Prospect Park and Jamaica Bay. The parrots stayed huddled in their airey fortresses for at least 10 minutes after the hawk's disappearance, but soon small groups of four birds each began to leave the nest to pursue their interrupted foraging. I would say it was at least 20 minutes before all the birds felt safe enough to reform the large group of foragers seen before the hawk's appearance.

Alas, our audio tape recorders were not activated when the alarm call issued, so it is impossible to characterize this call aside from it being strident and obviously clearly audible to every parrot within earshot.

For more on the monk parakeet's sentinel system, see Patterns of Flock Size, Diet, and Vigilance of Naturalized Monk Parakeets in Hyde Park, Chicago, a study by Jason M. South and Stephen Pruett-Jones.