Biological clock ticks slower for female birds that pick right mates

Washington, Jan 19 (ANI): A new study claims that choosing the right mates can slow down the ticking of biological clocks in some females birds.

Josh Auld of the National Evolutionary Synthesis Center in Durham, North Carolina, explained that birds become less fertile with age.

Older females lay fewer eggs, and they lay them later in the season - at a time when less food is available for their chicks, he explained.

When the authors analyzed lifetime data for nearly 600 females and 600 males from 1979 to 2007, they found how fast a female's fertility fades with age depends partly on her partners.

And it's not the age or identity of her mates that matter, but the past.

"The 'history' of the male matters," said co-author Anne Charmantier of France's National Center for Scientific Research.

"Females that repeatedly pair with early-reproducing males are better off. They don't age as fast," Auld said.

Males who got a head start on fatherhood may be healthier or more experienced mates than dads that delayed.

"The male helps the female build the nest, and he brings her food while she's laying and incubating the eggs. He also helps care for the hatchlings," Auld said.

The study appeared online in the January 12 issue of Oikos. (ANI)