California condors: Virgin births discovered in critically endangered birds.
The study's co-author said it is "truly an amazing discovery"
US wildlife researchers have discovered that two California condors, a critically endangered bird, gave birth without any male genetic DNA.
The discovery that condors are capable of virgin births - formally called parthenogenesis or asexual reproduction - surprised scientists.
Virgin births have been recorded in other bird species, as well as lizards, snakes, sharks, rays and other fish.
Only about 500 California condors remain in the US south-west and Mexico.
In the 1980s, fewer than two dozen birds remained in the wild, but conservation efforts have boosted their numbers in recent years.
The peer-reviewed findings from San Diego Zoo Wildlife Alliance were published this week in the American Genetic Association's Journal of Heredity.
The researchers describe how routine genetic screenings of captive birds led to the discovery that two male chicks hatched in 2001 and 2009 were related to their mothers and had not inherited DNA from any father bird.
