Virgin Births Seen in Wild Vipers
It usually takes two snakes — a female and a male — to make a litter of baby copperheads. But research now shows that copperheads and their venomous cousins cottonmouths don’t always require a partner to establish the next generation. These vipers are capable of virgin births.
For some vertebrates, parthenogenesis — asexual reproduction in which embryos develop without fertilization — is the norm. But in zoos and aquariums, zoologists have begun to document the strange phenomenon of facultative parthenogenesis: females of species that usually reproduce sexually, delivering offspring without mating. Surprise pregnancies have been documented among birds, sharks, snakes and Komodo dragons, but until now, only in captivity. Molecular ecologist Warren Booth now reports the first known case of wild facultative parthenogenesis, publishing the study in Biology Letters.