For the Birds Radio Program: Osprey
The Osprey may be smaller, but it’s better adapted for fishing than the Bald Eagle. It’s all in the feet. 3:45
Osprey, affectionately known as “fish hawks,” are wending their way along Hawk Ridge once again. Their 4 1/2 to 6-foot wingspan makes them visible from a long way off, and at this long distance we can recognize them by the crooked shape of their wings and their gleaming white forehead, which stands out from a surprisingly long way when one is flying straight toward us. Through last week, Osprey have been few and far between at Hawk Ridge—their migration will peak in a few weeks. We’ve had over 50 Osprey in a single day in early September at the Ridge, but even just one or two in a day is satisfying. Every close encounter with an Osprey is somehow memorable.
Osprey are one of the most wild and high-strung of all raptors. Even the finest rehab centers have trouble keeping them alive in captivity, even if an injury is quite minor. And reintroduction projects using captive-bred Osprey are virtually unheard of, simply because Osprey just don’t breed in captivity. These wild birds need their wild life.
An Osprey never harms a living thing except fish, but when one sees a fish, boy can it do a number on it. Osprey have unique feet, specially adapted for fish catching, with four toes of equal length covered with sharp scales called “spicules,” designed for sticking into slippery fish to hold them tight. Eagles have massive and sharp talons, but their three front toes and single back toe on each foot don’t oppose each other like an Osprey’s two front toes and two back toes do, and the short hind toe of the eagle just can’t dig into a fish the way the Osprey’s four equally long and balanced toes do. So the eagle’s favorite strategy for getting fresh fish is to sit around waiting for an Osprey to catch one, and then to harass the smaller predator until it drops the fish in midair. Then the eagle snatches it up, carries it home, and tells his wife he caught it.
We quickly recognize Osprey by their crooked wings, designed to pull them up and out of the water after plunging in after a fish. To make identification more challenging and interesting, we check out whether each one passing is a male or female, and try to figure out how old each is. Females have light streaking on the upper breast that forms a necklace—the throats of males are plainer. Immatures have pale feather edges on their back, and a white terminal tail band. The back of an adult is more solid blackish. Once in a while, an Osprey treats us by coming in close. Then we check out the eye color. Exactly opposite to accipiters, the eye of an adult Osprey is yellow, while that of immatures is orange to red.
Osprey eat only fish that they caught live, and in order to make their living over the long winter, they must travel far south of here. Osprey live year-round in Florida and South Texas, and don’t make room for their northern brethren, so our Osprey have to move all the way down to Mexico, Central America, and even South America. Birds aren’t protected in many of those countries, and DDT and other persistent pesticides are used there, so Osprey haven’t regained their numbers as dramatically as Bald Eagles, but they’re still definitely on the increase, enriching our world with their wild ways and their magnificent beauty.