California Condor Mortality Challenges
Two of the three California condor chicks that died had ingested foreign bodies, such as bottle caps, metal washers, and glass fragments.
As part of ongoing support of the California condor recovery program, the Wildlife Disease Laboratories of the San Diego Zoo's CRES has investigated a number of condor mortalities, including the unfortunate deaths of the three wild-hatched chicks. Previous data has shown that man-made hazards (such as powerlines and lead shot) are the biggest threat to the free ranging adult California condors Gymnogyps californianus. CRES' latest data surprisingly shows that man-made hazards also threaten chicks in the wild. Two of the three chicks that died had ingested foreign bodies, such as bottle caps, metal washers, and glass fragments, present in their nest caves and surrounding environment.
Field biologists believe that some of this material was brought in and cached by ravens that previously used these caves as nest sites. However, some of it could also have been brought in by the parents and fed to the chicks. The fact that one of these chicks died from zinc toxicity as a result of ingested foreign bodies clearly indicates the importance of such indirect anthropogenic threats even in these remote nesting locations. This data provides important feedback that will be used to optimize management of the free ranging population this next breeding season.
More
California Condor Recovery Program
Milestones in California Condor Conservation
Reintroduction of the California Condor to Baja California
Social Development and Reintroduction of California Condors
Studies of Courtship and Parental Care in Reintroduced California Condors in the U.S. and Mexico
