The
Osprey (Pandion haliaetus) is a large fish eating bird of prey that is
found world wide and is often called “Fish Hawk”. Their 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. Osprey are very vocal,
and utilize several calls including a begging call, and warning and alarm
calls.
Click here to listen to an osprey.
Osprey 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 wing span is almost
five feet while the male's is about four feet.
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 which 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 which 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 has recovered
considerably.