SAN DIEGO (AP) — A new study says endangered California condors can have “’virgin births.”

Researchers with the San Diego Zoo Wildlife Alliance say genetic testing confirmed that two male chicks hatched from unfertilized eggs in 2001 and 2009 were related to their mothers. Neither was related to a male.

It’s the first report of asexual reproduction in California condors, although parthenogenesis can occur in other species ranging from sharks to honey bees to Komodo dragons.

But in birds, it usually only occurs when females don’t have access to males. In this case, each mother had a mate.

The study was published Thursday in the Journal of Heredity.