OspreyTop
Description
The osprey is the only bird of prey that plunges into the water to capture fish. Ospreys
are large birds, black-brown on top and white below. Sometimes people confuse them with
bald eagles. The osprey’s white head has a broad, black cheek patch and its tail is
barred with brown, whereas a mature eagle’s head and tail are entirely white. The
osprey’s long, narrow wings are angled back at the wrist when it flies, and a black
wrist patch contrasts with white underwings. Bald eagles soar on broad, straight, dark
wings. Ospreys also are smaller than eagles. Male and female ospreys are similar in
appearance, although females may have a necklace of dark streaking. An osprey’s voice
is a series of sharp whistles and chirps, which become more frenzied if you approach the
nest. Top
Food
Ospreys feed primarily on fresh fish. They search for fish while flying 30-100 feet above
the water. If they spot prey, they hover, then plummet down, plunging into the water feet
first. Strong, curved talons and specialized spines on the bottoms of their feet help them
hold onto the slippery fish. If they catch the fish, they quickly take off, juggling it in
their feet until its head is facing forward into the wind. Then they fly to a perch to eat
it. Ospreys can’t swim and have been known to drown, especially if they get their
talons stuck in too large a fish and can’t take off. Top
Breeding Biology
When 3-4 years old, ospreys are sexually mature and will mate and nest. The birds are
territorial, defending their nest area from other ospreys. They select nesting sites near
water and build atop dead or living trees, or on power poles and other human made
structures. Sometimes they use old bald eagle or great blue heron nests. Mated pairs may
repair and use the same nest year after year. Top
The large nest, usually more than 3 feet in diameter, is made of big sticks and lined with
grasses and pond weeds. The female lays an average of 3 buff-colored, brown-speckled eggs,
which she incubates for about 28 days. The male brings fish to the female, who leaves the
nest only occasionally to exercise her wings. Top
Osprey chicks are especially vulnerable to the weather because their brownish natal down
doesn’t thicken or change into a warmer, second natal coat, as it does in other birds
or prey. Thus, the female remains at the nest to shield them from sun, rain and cold. At
this time, people should stay away from osprey nests to avoid frightening the female away.
When danger is near, the female signals to the young, who "play dead." Predators
like great horned owls, raccoons, ravens and crows will eat osprey chicks. Top
For the first few weeks, the female feeds the chicks semi-digested, regurgitated food.
Both parents feed older chicks small bits of fish. Young ospreys fledge when about 8 weeks
old, usually by mid-August. They stay near the nest and their parents until October. Then
ospreys begin their migration south. Top
Due to exposure, predation and accident, ospreys have a high death rate during their first
2 years. An average of 1 chick per nest fledges each year. Once the birds reach adulthood,
however, their chances for long-term survival are good. Ospreys can live as long as 20
years. Top
Distribution
Ospreys occur on all continents except Antarctica. Because they eat fish, they live along
rivers, lakes and coastlines. Top
