London, Aug 20 (ANI): A team of German scientists has found the secret of sexual success for flying foxes.
They found that males with relatively high levels of testosterone in their blood are better able to maintain their 'harem' of choosy females.
The authors say that this link is only evident during breeding season.
According to the researchers, a better understanding of the reproduction and behaviour of these bats could help efforts to conserve them.
Study's lead author Stefan Klose from the University of Ulm in Germany and colleagues examined grey-headed flying foxes, which are fruit-eating bats that live in colonies of up to 20,000 animals.
"This species is in decline. And flying foxes disperse seeds so they're really important for ecosystems," the BBC quoted Klose as saying.
The research team studied a colony of the flying foxes in New South Wales, Australia.
"In these colonies you see flying foxes hanging everywhere - it looks absolutely random, but that's not the case. Every metre of branch that you see is someone's territory. And within that [male's] territory, there is a group of females. The size of that group depends on the attractiveness of the male," Klose said.
Klose and his team counted the number of females in each male's harem, then captured a group of males using a special device to remove the bats directly from their branches.
"We kept the males in captivity for three days, and during that time we took a blood sample to determine the testosterone levels. Then we released the males back into the colony and watched where they went," Klose said.
During the mating period, males with high testosterone were better able to reclaim their harems, the researchers found.
"This was when all the matings took place - when it really mattered," Klose said.
He explained that one of the roles of testosterone, which is the primary male sex hormone, is the mediation of aggression. So a male with high testosterone levels is likely to have more confrontations with other males.
"If you can afford high testosterone because you're strong and you're very healthy, then you're able to reap the benefits. So you will potentially get a lot of females in your territory and have a lot of offspring," Klose said.
He also suggested that a larger territory might be a 'quality indicator' to females.
"It's all about female choice. So you could imagine that the females think that if a male is able to defend a large territory in an attractive location, he must really be a hotshot," Klose said.
The study has been published in the Royal Society journal Biology Letters. (ANI)