California condors have laid six eggs on the same day in what scientists believe to be the first “virgin birth” of a captive breeding pair in the west in half a century.
The chick is about the size of a beehive in its mother’s nest on a remote rock ledge in the far west of the California mountain range, about 60 miles (96km) south of Tucson. Its parents’ incubation period is expected to last until the end of February.
“These birds are going to lay their eggs for a long time, for many months,” said Susan Gantz, director of the Condor Recovery Program at the San Diego Zoo.
The chicks will be released into the wild when they are about two months old. Condors don’t lose their wings until they’re three to four years old.
“It’s a significant milestone and this is certainly a time for all of us who work with these birds to hold our breath and hope for a long healthy life for these birds,” said Gantz.
The Condor Recovery Program became part of the US government’s endangered species list in 1972. The fragile birds are protected by law and have been classified as threatened since 1993.
Other captive breeding efforts are under way in Arizona and California. The San Diego Zoo has four nests, including two with the female and male juvenile pair, and one with a second adult and two chicks. Scientists hope to release 40 chicks this year to dozens of protected condor nests.
John Badura, a scientist with the California condor recovery program, holds a wild California condor chick at the Bird Ridge Wild Animal Preserve in La Paz, Arizona, on Wednesday. Photograph: Alex Brandon/AP
Scientists are also working on a longer-term strategy to provide long-term genetic diversity by breeding all female adult condors in captivity in a “homing zone” in the western United States.
“At least there’s biological diversification now,” said Badura. “We have females around the world and that’s more than when I first started 20 years ago.”
The L-ring tail of a California condor. Photograph: Patrick Semansky/AP
Only 26 condors live in the wild, mostly in remote, isolated areas of northern Arizona and southern California. Some breeding pairs have successfully fledged chicks.
But fewer than 70 of more than 1,100 birds originally collected in the 1970s have been transferred to Southern California, where the survival rate has dropped dramatically because of encroachment by humans, lightning and other natural events.
The captive breeding program, however, has had successes with breeding that has meant more than 50 breeding pairs have fledged chicks, a record set in 2013.
“The number of birds with reproductive ability has increased,” said Badura. “We’re able to show an inter-breeding area is being formed.”