In Missouri, ospreys can be seen most frequently in spring when they are flying through the state to nesting areas further north and again in fall when they fly south to their winter range in South America.
Scientific name: Pandion haliaetus
Nicknames: fish hawk
Claim to fame: These large raptors are well known for their hunting method of plunging into the water to snatch fish. Because of their heavy reliance on fish, ospreys can serve an indicator species for monitoring the long-term health of large reservoirs and rivers. Ospreys also have an aesthetic/charismatic value to them which can benefit the eco-tourism of an area. In Missouri, ospreys can be seen most frequently in spring when they are flying through the state to nesting areas further north and again in fall when they fly south to their winter range in South America.
Species status: Ospreys are found on every continent except Antarctica. They were once numerous throughout North America, but they experienced a significant population decline during the first half of the 1900s due to pesticide contamination of the fish they consume. Ospreys were present in Missouri in pre-settlement times, although it is thought they were never plentiful. The state’s resident breeding population disappeared long before the use of DDT. Osprey restoration began in Missouri in 1995 when birds were turned loose at selected release sites across the state (one of which was Truman Reservoir). Through these efforts, it was hoped the bird would re-establish itself as a summer nester in Missouri. Osprey habitat, which today is primarily in the form of large reservoirs, is more prevalent than it was during the bird’s original occupation of Missouri. Because of this, the bird’s future in the state looks promising.
First discovered: The first scientific description of the osprey was written by the famed naturalist Carl Linnaeus in 1758.
Family matters: The osprey is the sole member of the family Pandionidae. Biological families that contain only one species are known as monotypic families. This type of taxonomical categorization is unusual, but other examples can be found. One well-known example is the walrus (Odobenus rosmarus), which is the sole member of the mammal family Odobenidae.
Length: 21 to 24 inches to 8 inches; wingspan of four to six feet
Diet: Studies have shown that somewhere around 99 percent of an osprey’s diet is fish. A hunting osprey usually flies 50 feet to 200 feet above a body of water while looking for fish near the surface. When the bird sees a fish, it hovers before diving into the water feet first. Often it completely submerges itself except for the wings. Once the fish is securely grasped, the osprey carries it to a perch or nest. In flight, fish are carried head-first so they offer less wind resistance.
Weight: three to four pounds
Distinguishing characteristics: An osprey is mainly white when viewed from below, with dark speckles on the breast, barring on wings and tail and a dark patch at the bend of the wing. They have a dark brown back and a dark eye-line (a mask-like marking) on a white head. Ospreys emit a loud, clear whistle – often in a series and sometimes in response to other ospreys.
Life span: Ospreys have been known to live up to 25 years.
Habitat: Because of their reliance on fish, the main requirement of an ospreys’ habitat is that it must be near water.
Life cycle: Courtship and pairing occurs in early spring. Nests are often re-used and added to and, in the course of several years of nesting, can become large structures. A clutch of from two to four eggs is laid. The eggs hatch in three days. Another eight or nine weeks is required for the young to mature and fly from the nest.