CAPTURE AND BANDING OF MIGRANT RAPTORS

ABSTRACT

There are relatively few places worldwide where migrating raptors can be captured in numbers. Two such places are Cape May Point in southern New Jersey in the United States, in operation for 27 years, and Elat in southern Israel, operated for five years. Migrant raptors were captured, and numbered bands (rings) were placed on their legs. Information about migration pathways, breeding areas, and nonbreeding areas could be inferred from the recovery of these bands in other locations. To get a large enough sample of band recoveries, one must capture and band many raptor migrants. The recovery rates from Cape May Point and Elat are compared. Capture and banding as a method to study raptor migration has the advantage that researchers can get a large sample of raptors that come from a broad area, and, while handling them, can determine their age, sex, and physical condition, as well as obtain photographic documentation and samples of blood, feathers, parasites, and tissues. Records of environmental pollution, such as oil contamination, can also be obtained during handling. Deviations in age distribution and sex ratios of the captured birds in comparison to the general population are assumed to be due mainly to differences in survival and capture rates and migrational pathways.