Scientists with the University of Western Australia compared the sperm of endangered and non-threatened mammals, from the giant panda to the familiar domestic cat, to better understand the link between sperm quality and inbreeding.
Dr John Fitzpatrick and Dr Jon Evans from UWA's Centre for Evolutionary Biology analysed sperm data from 20 species including, among others, the panther, lion, cheetah, giant panda, bison and howler monkey.
Their work has been published in the prestigious Royal Society journal Biology Letters.
"We show that the most inbred species had more sperm abnormalities and fewer motile (mobile) sperm, and that inbreeding can severely reduce male reproductive fitness. Genetic viability and reproductive potential are therefore important considerations when restoring threatened populations."
Dr Fitzpatrick said he and Dr Evans used data from various published sources and that their results were directly applicable to any endangered species, including those native to Australia.
"We show that those endangered species with the most severe loss of genetic variability had the poorest ejaculate quality. Since sperm quality is an essential part of breeding programs, and hence species restoration, our results highlight that preserving genetic variability is essential for preserving a species' reproductive capacity," he said.
This study is sure to have key implications for species conservation, it is pointed out.