        |
Australian subspecies:
Pandion haliaetus cristatus
The osprey is related to hawks and eagles though sufficiently different to be classified in its own family, Pandionidae, of which it is the only member.
Ospreys are found throughout the world, on all continents except Antarctica, and always near water.
They are classified into sub-species to distinguish regional variations in colour and size. Throughout their range they are more likely to frequent coastal habitat than freshwater lakes.
Some populations are migratory. Those from warmer regions perhaps tend to be more sedentary because of a year round food source. In Australia, ospreys are more common in the north, but are found on all coasts except Victoria and Tasmania.
These are large raptors with adult wingspans that can exceed 1.5 metres. They can weigh more than 2 kilograms. A dark mask and bright orange eyes are distinguishing features of the head.
Young birds have a bib of mottled brown and white feathers which fades with maturity.
Strong legs and large feet with sharp talons are hallmarks of the species, and its tools of trade. As an aid to gripping fish, the undersides of the feet are equipped with numerous spicules.
This bird preys spectacularly and almost exclusively on fish - hence its common name of fish hawk. Usually hunting alone, it will fly over water on the lookout for fish at or near the surface. When a target is spotted, the bird folds wings and plummets, thrusting its strong talons forward, just before impact, to snatch the fish.
The kill is usually a quick episode with the osprey winning its prize and flying off to a vantage point to eat. Ever mindful of aerodynamics, the osprey will manoeuvre a fish in its talons so the head points forward to minimise air resistance. Often the bird does a comical mid air shimmy, shaking wings and tail to shed water collected during splashdown.
Sometimes its talons lock onto a fish which puts up strong resistance. A thrashing tussle ensues on the surface as the bird and fish fight it out. If victorious, the osprey can take off carrying a fish payload up to one third of its own bodyweight.
If the fish wins? At best the osprey suffers a severe dunking and loss of pride. At worst it can be dragged under and drowned (a large salmon with the talons and skeletal remains of an osprey's leg embedded in its back was once caught by a fisherman).
Ospreys are monogamous and thought to mate for life. They build large nests using sticks, seaweed and man-made materials like rope and wire. Nests are sometimes built on the ground if land-based predators are absent. More often, they are built in large, dead trees with a commanding view of territory.
Nests may remain in use for many years, having new materials added as the seasons come and go. Sometimes, possibly due to parasites or other contamination, the adult birds will partially dismantle a nest before rebuilding it.
Where suitable natural nest sites are scarce, ospreys will build their nests on man-made structures like electric power poles. They lay 3-4 eggs which hatch in about 30 days.
Ospreys are only known to nest on four continents: North America; Europe; Asia; and Australia.
Photographs by David Bennett -Country Energy
Osprey call - as GIF
Visit the Australasian Raptor Association site
Visit the University of Minnesota Raptor Centre
my account
environment
how to be green
© Country Energy 2010 - 
Read more