California condors: status of the recovery effort

Abstract

Disturbance and high mortality related to human activity have apparently caused the decline of the condor population to about 50 birds. Failure to reproduce successfully is now the central problem; inadequate food supply near nest sites, lack of nest sites in new concentration areas, and pesticide accumulation in condor tissues are possible causes. Low reproductive rate hinders the recovery effort. Results of population modeling indicate that a minimum of eight nesting attempts each year is needed to maintain a population of at least 50; field data indicate that an average of only 1.8 young were produced per year from 1966 through 1976. Principal recommendations include analysis of vegetation structure in the condor range by aerial photographic interpretation; attempts to mark condors for life; standardization of counting procedures; and approval and funding of the proposal to rear condors in captivity.

Citation

Verner, Jared. 1978. California condors: status of the recovery effort. Gen. Tech. Rep. PSW-28. Berkeley, Calif.: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Exp. Stn. 30 p