Wild Animal Park-produced Condor Egg Given to Wild Condors

May 21, 2007

Biologists with the U.S. Fish and Wildlife Service's California Condor Recovery Program confirmed a California condor egg produced at the San Diego Zoo's Wild Animal Park hatched last week near the Hopper Mountain National Wildlife Refuge after the egg was placed in a wild birds' nest May 13.

A breeding pair of California condors, male No. 125 and female No. 111, produced an egg earlier this year in the remote backcountry of the Los Padres National Forest adjacent to the Refuge. Although the egg was infertile, the pair continued to care for it. U.S. Fish and Wildlife Service (USFWS) requested an egg that was days away from hatching from the Wild Animal Park condor team to replace the infertile one.

"Aside from raising California condor chicks at the San Diego Zoo's Wild Animal Park to support the condor program, it is equally exciting to transport an egg produced here and place it in the wild," said Michael Mace, Wild Animal Park curator of birds. "We look forward to seeing the chick flying in the skies of California."

The pair is part of a first-of-its-kind micro trash aversion program conducted by the Wild Animal Park. Together, condors 125 and 111 previously produced three chicks in the wild, but each time the chicks died from ingesting micro trash items including broken glass, plastic hardware and bottle caps brought to the nest by the parents. Although it remains unclear as to when the condors feed these items to their offspring, one theory is the adult condors appear to be mistaking micro trash for bone chips that are fed to their chicks as nutritional supplements. When the pair was unable to successfully rear a third chick, USFWS officials caught the pair and sent it to the Wild Animal Park in 2006.

The pair underwent trash aversion training during the 2006 breeding season. Micro trash items were placed on a panel on the ground that exerts a mild electric shock to the touch, meant to discourage the birds from picking up trash and instead choose bone chips to feed to their chicks.

Condors 125 and 111 successfully raised a chick at the Wild Animal Park in 2006. The pair laid the infertile egg after their release earlier this year and is one of six condor pairs raising chicks in the wild. Biologists will monitor this pair and examine the chick over the next six months to determine if the aversion training is a success.

The Wild Animal Park egg was laid Jan. 16. To date, 136 California condor chicks have hatched at the Wild Animal Park. Two eggs are still being incubated.

The California Condor Recovery Program is built upon a foundation of private and public partnerships. The focus of the condor recovery effort is the release of captive reared condors to the wild to ultimately establish self-sustaining populations.