Offspring of promiscuous frogs have better survival rates

SYDNEY - The offspring of promiscuous female frogs have a higher rate of survival than those who remain monogamous, new research says.

One of nature’s mysteries is why some females mate with multiple males (polyandry) despite the risk of disease transmission, potential injury and even increased predation risk.

“One hypothesis to explain this behaviour is that females accrue genetic benefits that improve offspring viability, but until now, this remains largely untested,” said Martin Whiting, biologist and associate professor at Macquarie University.

Along with fellow researcher Philip Byrne from the University of Wollongong, Whiting investigated whether simultaneous polyandry influences offspring fitness in a wild population of the African Grey Foam Nest Treefrog (Chiromantis xerampelina).

“Simultaneous polyandry in this frog is the most extreme reported for any vertebrate, with more than 90 percent of females mating with 10 or more males during the deposition of a single clutch,” Whiting said, according to a Macquarie University statement.

Whiting and Byrne compared growth (using age and size at metamorphosis as proxies) and survival of offspring produced by females that naturally mated with either one male (monogamous female) or 10-12 males (polyandrous females).

Polyandry did not influence size or age at metamorphosis from a tadpole, but offspring from polyandrous matings had significantly higher mean survival.