AUSTRALIA: Endangered animals face lower fertility

The world's endangered species face a double whammy of threats to their survival - as their numbers reduce, the chances of inbreeding increase and a new study now shows that this in turn reduces their fertility.

Scientists at 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. They aimed to find out if reductions in the quality of sperm might be behind reductions in fertility commonly associated with inbreeding.

Dr John Fitzpatrick and Dr Jon Evans from the university's Centre for Evolutionary Biology analysed sperm data from 20 species including, among others, the panther, lion, cheetah, giant panda, bison and howler monkey.

"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."

Fitzpatrick said endangered species with the most severe loss of genetic variability had the poorest ejaculate quality. "Since sperm quality is an essential part of breeding programmes, and hence species restoration, our results highlight that preserving genetic variability is essential for preserving a species' reproductive capacity," he said.

The study was published in the prestigious Royal Society journal Biology Letters last week. The article is available here.