Tuesday, 6 August 2013

Canadian Species Spotlight - The Osprey


The Osprey sometimes known as the sea hawk, fish eagle, or fish hawk, is a fish-eating bird of prey. It is a large raptor, reaching more than 60 cm (24 in) in length and 180 cm (71 in) across the wings. It is brown on the upperparts and predominantly greyish on the head and underparts, with a black eye patch and wings. In 1994, the osprey was declared the provincial bird of Nova Scotia, Canada

The Osprey tolerates a wide variety of habitats, nesting in any location near a body of water providing an adequate food supply. It is found on all continents except Antarctica, although in South America it occurs only as a non-breeding migrant.

As its other common name suggests, the Osprey's diet consists almost exclusively of fish. It possesses specialized physical characteristics and exhibits unique behavior to assist in hunting and catching prey. As a result of these unique characteristics, it has been given its own family.

The Osprey is the second most widely distributed raptor species, after the Peregrine Falcon. It has a worldwide distribution and is found in temperate and tropical regions of all continents except Antarctica. In North America it breeds from Alaska and Newfoundland south to the Gulf Coast and Florida, wintering further south from the southern United States through to Argentina.

The Osprey breeds near freshwater lakes, and sometimes on coastal brackish waters. The nest is a large heap of sticks, driftwood and seaweed built in forks of trees, rocky outcrops, utility poles, artificial platforms or offshore islets. Generally, Ospreys reach sexual maturity and begin breeding around the age of three to four, though in some regions with high Osprey densities, they may not start breeding until five to seven years old, and there may be a shortage of suitable tall structures. If there are no nesting sites available, young Ospreys may be forced to delay breeding. To ease this problem, posts are sometimes erected to provide more sites suitable for nest building.

Ospreys usually mate for life. Rarely, polyandry has been recorded. The breeding season varies according to latitude. In spring the pair begins a five-month period of partnership to raise their young. The female lays two to four eggs within a month, and relies on the size of the nest to conserve heat. The eggs are whitish with bold splotches of reddish-brown and are about 6.2 by 4.5 cm (2.4 by 1.8 in) and weigh about 65 g (2.3 oz). The eggs are incubated for about 5 weeks to hatching.

The newly hatched chicks weigh only 50–60 g (1.8–2.1 oz), but fledge in 8–10 weeks. When food is scarce, the first chicks to hatch are most likely to survive. The typical lifespan is 7–10 years, though rarely individuals can grow to as old as 20–25 years. The oldest European wild osprey on record lived to be over thirty years of age. In North America Bubo owls and Bald Eagles (and possibly other eagles of comparable size) are the only major predators of both nests and sub adults.

You can often find Osprey flying around and fishing in many of the lakes and streams we visit on our workshops with North of 49 Photography. www.northof49photography.com

Please check out our workshops and contact us if you see anything that interests you.

Kev