SFRC M-679 Status of the Osprey in Everglades National Park

Bass, Oron; Kushlan, James

Osprey (Pandion haliaetus) populations ni various parts of North America decreased during the 1950's and 1960's, primarily because of pesticide contamination with eastern populations being most affected (Jenny and Ogden 1970). These populations are migratory and winter in the West Indies and in Central and South America (Zarn 1974). The Florida population, considered to be non-migratory by Ogden (1978), contained low levels of pesticide contaminates. The major cause of localized population decreases that have taken place in the state has been destruction of habitat (Ogden 1978). These ospreys nest throughout Florida, but nesting birds are less common in northwestern Florida and rare around the Gulf of Mexico (Ogden, 1978). Nesting near bodies of water such as lakes, rivers, and coastal areas, breeding ospreys are particularly common along the St. Johns River, in Ocala National Forest and in Everglades National Park. The status of a major segment of the latter population was documented between 1968 and 1974 by Ogden (1975, 1977). He conducted aerial surveys in Florida Bay in the late 1960's and early 1970's and measured nesting effort and productivity on three islands. He concluded that the Florida Bay osprey population was stable (Henny and Ogden 1970), and on three study islands, that they number of ospreys and percentage of successful nests remained approximately constant over five years (Ogden 1977).

SFRC M-679 Status of the Osprey in Everglades National Park

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