Flutterby™! : who's got the biggest?

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who's got the biggest?

2006-01-25 16:05:15.342604+00 by Dan Lyke 1 comments

Seeing links this morning to a New Scientist article that notes an inverse correlation between size of testes and brains in bats, and links these things to promiscuity in females of the species:

Pitnick and his colleagues had predicted that, in species with promiscuous females, males would require bigger brains in order avoid being cuckolded. So they were surprised to find the opposite: “Perhaps monogamy is more neurologically demanding.”

From the Syracuse University press release:

“When females mate with more than one male, sperm compete to fertilize the female’s eggs. Such ‘sperm competition’ is rife in many bat species, perhaps due in part to the unusual ability (among mammals at least) of sperm to survive inside the female’s reproductive tract for a very long time,” says Pitnick. “The male who ejaculates the greatest number of sperm may win at this game, and hence many bats have evolved outrageously big testes—as much as 8.5% of their body mass. Because they live on an energetic knife-edge, bats may not be able to evolutionarily afford both big testes and big brains. We’re excited about these results, as they may stimulate more research into the correlated evolution of brains, behavior and the extravagant and costly ornaments and armaments favored by sexual selection.”

The full study is available at Proceedings of the Royal Society: Biological Sciences: Mating system and brain size in bats.

[ related topics: Sexual Culture Nature and environment Biology ]

comments in ascending chronological order (reverse):

#Comment Re: made: 2006-01-25 16:53:51.646095+00 by: meuon

Having spent a lot of time with bats (including caving in a very active vampire bat cave in Mexico), I know one thing about them: They are very odd little beasts. I'd be wary of any correlations from them to human-kind, or for that matter, any other animal.