Remote-Url: https://www.nytimes.com/2021/10/30/science/san-diego-zoo-condor-virgin-births.html
Retrieved-at: 2021-10-31 10:30:12.050534+00:00

California condors have long been an endangered species, with the world population falling to just 23 in 1982,according to the U.S. Fish and Wildlife Service. At that point, the agency pulled all the known California condors out of the wild and bred them in captivity.The species, which in 2020 numbered 504 birds, has been closely monitored and studied for decades, leading to discoveries like the one published Thursday, said Samantha Wisely, a conservation geneticist at the University of Florida who was not involved in the study.The need to identify the birds by sex in order to develop a successful breeding program led to the discovery about the two chicks.Years ago, Dr. Ryder was asked to develop a system for identifying the sex of the California condors in captivity because males and females look the same. He also had to identify close relatives among the birds so that relatives would not be paired. So he created a genetic database for all California condors.In 2013, Dr. Ryder’s team noticed some discrepancies in the database, which prompted a re-analysis of all the birds in captivity. Dr. Ryder’s team discovered two male chicks — one born in 2001, the other in 2009 — that didn’t match any of the males’ genetic profiles. That meant that none of the male condors had fathered them.