Park Science

Breeding raptor inventory

Raptors are regarded as ecologically important but are threatened in all three parks. For example, contamination of the environment resulted in the extirpation of the bald eagle from the Channel Islands. The bald eagle historically ranged on the Channel Islands and may have helped exclude golden eagles, a recently arrived predator of the sensitive island fox. In the Santa Monica Mountains, raptor species diversity is especially rich, but on-going urban development and human activities may be threatening the long-term persistence of some species. At Cabrillo National Monument, raptors play an important role in this well-preserved "island" of southern California coastal sage scrub. At all three parks, very little information is available about raptor abundance and nesting distribution. Due to funding restrictions, the inventory of raptors was limited to Cabrillo National Monument and Santa Monica Mountains National Recreation Area and only to diurnal breeding raptors. Relative abundance of adult raptors and absolute abundance of raptor nest sites were obtained by way of foot, vehicle, boat, and helicopter surveys.