Osprey

Osprey   

Pandion haliaetus


Pandion haliaetus English: An Osprey preparing...The osprey or ‘fish-hawk’ is a bird of prey that nests near large areas of water. Ospreys can be found along Lake Champlain and may occasionally be seen fishing on other water bodies.

Smaller and more streamlined than eagles, ospreys are still large birds of prey- approximately 21 to 26 inches in body length. Adult birds have a wingspan of 59 to 67 inches and weigh about 3.5 pounds. In flight, the osprey’s long, narrow wings appear to have a crook at the wrist where dark patches are apparent.

Characteristics

The crooked bend of the wings in flight is the prominent characteristic of the osprey. Ospreys have dark brown backs with white undersides and a lightly brown-spotted breast; although this spotting may be absent in males. Females are generally slightly larger than the males. Juveniles have a speckled back and wings and red eyes; their  plumage resembles that of the adult, with buff to white tips on the feathers of the back and upper wing.

Bright yellow eyes stare from a small, narrow white head with a dark crown. The head features a dark brown streak through the eye area. Sharp talons, used for hunting, protrude from the end of powerful legs.

The osprey  makes a clear whistling noise to shrill cries indicate increasing levels of alarm. Listen for a slow whistled guard call – “kyew-kyew-kyew”. The osprey alarm call is a short clear whistle that increases to faster, higher squeals.

Food

Ospreys feed primarily on live fish, which they catch by using their long, hooked talons. The primary food is fish that swim close to the surface such as perch, suckers, and bullhead that ospreys capture by plummeting from the air and grabbing with their talons. Sometimes the osprey plunges deep enough to submerge its entire body.

Habitat & Distribution

Ospreys breed near large bodies of water with an abundant supply of fish. In the Lake Champlain Basin they nest near lakes and rivers, occasionally in loose colonies. Breeding occurs from Maine to Florida. Many ospreys from  the Lake Champlain Basin are likely to spend their winters as far south as Central America.

An osprey nest is a large, bulky pile of sticks, put together on the top of a tall dead tree, a rocky ledge, telephone pole cross arms, or an artificial platform. In the spring the female lays one to four, but usually three,  white or milky-white eggs, heavily marked with brown. Ospreys often use the same nest year after year and add more sticks each year. Some of these nests can become quite large- sometimes up to 10 feet tall! The young fledge at about eight weeks of age, then remain in the area of the nest for about two months.

Osprey Threats

  • DDT- used as an insecticide until banned in the U.S. in the early 1970s. It widely dispersed throughout the environment where it takes years to break down. Ospreys ingested the DDT when feeding on fish. The result was thinner eggshells that broke during incubation.
  • Ospreys like to nest in tall dead trees, but these trees may fall during the year, resulting in fewer available nesting sites.
  • In areas where there are dams and channels, the natural flow of water is altered and the availability of fish may change; this can cause ospreys  to move to a new location.
  • Disturbances at nest sites such as predation and human intrusion have had some effects on the osprey population.

Management Efforts

Higher productivity of ospreys in Vermont in recent years has occurred due to the efforts of many people and organizations including state Fish & Game Departments, the U.S. Fish and Wildlife Service, and power companies. Management activities include:

  • Artificial nesting platforms put up in appropriate areas through cooperation with power companies and other landowners.Many have been used by ospreys to build nests and raise young.
  • Bands of metal (predator guards) are placed around trees and platform poles where ospreys are nesting to minimize the approach of predators from the ground.
  • Nesting areas are monitored so the number of nesting osprey can be tracked and disturbances by people can be minimized through placement of warning signs if needed.
  • Observations are noted as to where ospreys frequently occur so that nesting platforms can be put up in those areas.

How You Can Help

Recent management efforts to provide safe and sturdy nest sites in the best foraging habitats have contributed to increased breeding success. Due to the sensitivity of these birds to disturbance, people are encouraged to remain at least 300 feet from nesting areas during this period.

  • Avoid getting too close to nesting sites during the breeding season.
  • Honor warning signs when posted.
  • Maintain a respectful distance from wild animals. Travel with binoculars! If an animal vocalizes when you’re near its territory, immediately back off.
  • Observe and report on osprey nesting activities in your area.

 

Osprey landing in nest

 

Helpul Articles:

Osprey (dec.ny.gov)

Osprey (vtfishandwildlife.com)

Osprey Fact Sheet (NYS Dept. Environmental Conservation)

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