The mane attraction: lionesses prefer dark-haired lions

Longer, darker mane means more female mates and less male rivals

A male lion may swelter in the heat under his long, dark mane, but a new study suggests the pain is worth it lionesses find dark, shaggy manes a turn-on.

Not only does having a bigger, blacker mane mean more mates, but the lion is able to intimidate other adult males and better protect his cubs, says the study to be published Friday in the journal Science.

"The results of these tests have been very exciting, and suggest that the manes do play a role in sexual selection," said researcher Peyton West of the University of Minnesota, who is writing her thesis on the topic.

The main reason lions with dark manes are attractive is that they have higher levels of testosterone. "It isn't surprising that females would prefer darker manes and males would be intimidating," said West.

Like a peacock's tail, the colour and weight of the lion's mane gives off signals to lionesses about his health and fitness. In the wild, male strength is a desirable quality, said West, and a short mane is often a sign of recent injury.

But lions pay the price for their attractiveness. Using an infrared camera, West discovered males with manes were much hotter than those without manes. They also eat less in the summer, have difficulty camouflaging themselves, and produce more abnormal sperm.

It was first suggested that manes are used for protection in fights, but West and adviser Professor Craig Packer said their data didn't show the neck and head were a special target in fights.

In their study, West and Packer set up pairs of life-size dummy lions with different length and colour of manes about 200 metres from real adult lions in Tanzania's Serengeti National Park. They found males chose to approach the short-maned dummy nine out of 10 times, while females approached the darker-maned dummy 13 of 14 times.

Manes vary from light blond to black and can be up to a foot long. Most adult males observed at Kenya's Tsavo National Park are mostly maneless, while some in the Serengeti Plain of Tanzania sport large manes. But the Barbary lion of the Atlas Mountains and the Cape lion of South Africa all sport giant dark manes that cover their stomachs.

The study, done through the Lion Research Center, was paid for by the National Science Foundation.