Earth Almanac: March/April 2006

Spring Fishing

When northern lakes and estuaries are still rimmed with ice, the osprey—a.k.a. the fish hawk—welcomes spring with a shrill, ascending kyew, kyew, kyew. On every continent save Antarctica, you'll see these white-crowned, black-masked raptors hovering over water or perched on stick nests that can weigh 1,000 pounds. Note the slightly crooked wings that can span six feet, the long legs, and the aerial acrobatics of courting males. Ospreys will take the odd mink, muskrat, or snake, but their diet is almost exclusively fish. They're not closely related to other hawks, apparently having veered off on a separate path early in their evolution; some taxonomists even place them in a family by themselves. Spines on footpads and a front claw that swivels to the back assist in gripping their slippery prey. Oil in their feathers repels water. Ospreys hit the surface in an explosion of spray, closing their nostrils (unlike bald eagles, they can submerge completely); then they rise laboriously, shaking like a dog. If they've been successful, they'll immediately turn the fish so the head points forward. Sometimes an osprey will strike a fish that's too big for it and, unable to release its talons, will drown. Recently a Bahamian conch fisherman from South Andros Island found a dead osprey clutching a dead barracuda. He ate them both.