SYRACUSE, N.Y. - For some male bats, sexual prowess comes with a price — smaller brains. A research team led by Syracuse University biologist Scott Pitnick found that in bat species where the females are promiscuous, the males boasting the largest testicles also had the smallest brains. Conversely, where the females were faithful, the males had smaller testes and larger brains.

“It turns out size does matter,” said Pitnick, whose findings were published in December in “Proceedings of the Royal Society: Biological Science,” an online journal.

The study offers evidence that males — at least in some species — make an evolutionary trade-off between intelligence and sexual prowess, said David Hoskens, a biologist at the Centre for Ecology and Conservation at the University of Exeter in England and a leading authority on bats’ mating behavior.

“Bats invest an enormous amount in testis, and the investment has to come from somewhere. There are no free lunches,” said Hoskens, who did not participate in the study.
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Pitnick’s team looked at 334 species of bats and found a convincing contrast in testes size. In species with monogamous females, males had testes starting at 0.11 percent of their body weight and ranging up to 1.4 percent. But in species where the females had a large number of mates, Pitnick found testes ranged from 0.6 percent to 8.5 percent of the males’ mass (in the Rafinesque’s big-eared bat).

“If female bats mate with more than one male, a sperm competition begins,” Pitnick said. “The male who ejaculates the greatest number of sperm wins the game, and hence many bats have evolved outrageously big testes.”

Promiscuity is known to make a difference in testicle size in some other mammals. For example, chimpanzees are promiscuous and have testicles that are many times larger than those of gorillas, in which a single dominant male has exclusive access to a harem of females.

Large brains, meanwhile, are metabolically costly to develop and maintain. Pitnick’s research suggested that in those bat species with promiscuous females, the male’s body used more of its energy to enhance the testes — giving it the greater adaptive advantage — and lacked the energy it needed to further develop the brain.

The study found that in more monogamous species, the average male brain size was about 2.6 percent of body weight, while in promiscuous species, the average size dipped to 1.9 percent.

LOS ANGELES (Reuters) - The video game industry’s 2006 E3Expo trade show in Los Angeles is getting a make-over — banned are the swarms of sexy, semi-clad “booth babes” that in years past took the unveiling of new games and technology to titillating new levels.

Rules prohibiting the use of scantily clad young women to peddle video games are nothing new, but the handbook for this year’s show in May outlines tough new penalties, including a $5,000 fine on the spot for the booth owner if the “booth babe” is semi-clad.

“What’s new in 2006 is an update and clarification of the enforcement policies; as we do from time to time, we have taken steps to ensure that exhibitors are familiar with the policy and how it will be enforced,” Mary Dolaher, E3Expo show director, said in an e-mail.

She did not comment on the reasons for the change.

The video game industry has come under fire from federal and local politicians, who want to limit sales of violent and sexually explicit games to minors.

The handbook from the Entertainment Software Association, the show’s promoter, says: “Material, including live models, conduct that is sexually explicit and/or sexually provocative, including but not limited to nudity, partial nudity and bathing suit bottoms, are prohibited on the show floor, all common areas, and at any access points to the show.”

Exhibitors would receive one verbal warning when a violation occurs. Upon a second violation, the ESA said it would impose a $5,000 penalty, payable immediately on the site. It would also require that models comply with the dress code before returning to the floor.