The Osprey, Pandion haliaetus, is a large fish eating bird of prey that is found worldwide and is often called “fish hawk”. The osprey diet consists almost entirely of fish. When hunting, the Osprey will hover 50’ to 150’ above the water, spot a fish and dive feet first into the water, sometimes completely submerging. When the osprey emerges, it shakes the water from its feathers and then will arrange the fish in its talons to face forward to reduce drag during flight. Ospreys are very vocal, and utilize several calls including a begging call, and warning and alarm calls.
Click here to listen to an Osprey
Ospreys have several specialized and interesting anatomical features that distinguish them from other birds of prey. For instance they have a reversible fourth toe and very long strongly curved talons. They also have spines called “spicules” on their feet. All of these adaptations aid the Osprey in holding on to its slippery prey.
Like many raptors, the female is larger than the male. The female's wingspan is almost five feet while the male's is about four feet. The males have a white chest and the females have brown splotches on their chest.
Male above and female below
Osprey build nests consisting of a mass of sticks in the tops of dead trees, navigational buoys and man-made platforms. The nests may be reused over many years. Osprey in the Dunedin area generally lay their eggs from December to February. For 32 to 35 days, the pair incubates two to four eggs that are yellowish in color and blotched with reddish brown. After the eggs hatch, it takes nine to ten weeks for the young to leave the nest.
The Osprey suffered considerably during the mid 20th century. The effects of DDT contamination caused the eggs to have very thin shells that were easily broken under the weight of the incubating adults. As a result, Osprey numbers dropped drastically in much of North America. Since the banning of DDT in the mid 1970s, populations of this magnificent bird have recovered considerably.