A big, black mane is hot, shaggy and attracts trophy hunters, but it makes a lion irresistibly sexy to the lionesses

A big, black mane is hot, shaggy and attracts trophy hunters, but it makes a lion irresistibly sexy to the lionesses, researchers reported.

The bigger and darker the mane, the more mates a lion attracts, and the better his cubs survive, Peyton West and Craig Packer of the University of Minnesota wrote in Friday's issue of the journal Science.

A male with a long, dark mane intimidates other lions and for good reasons, they found. He has higher levels of testosterone and wins fights more often.

But he pays for this. He is hotter than lions with lighter manes, eats less in summer and produces more abnormal sperm, the researchers found.

"We suggest the mane's evolution is the result of sexual selection," said West, a doctoral candidate whose dissertation led to the paper.

Lions' manes vary from light blond to black and can be up to a foot long.

One big question about lions is why the males even have a mane, said West, who studied lions in Tanzania's Serengeti National Park.

Like a peacock's elegant but heavy tail, it signals biological fitness to females. Females choose mates with beautiful tails, or in the case of lions, with big, black manes, because it turns them on. Thus the trait is passed on.

West checked to see what good the mane does to a lion. Some people have suggested it protects the head and shoulders during fights or hunting, but West said their data didn't show the neck and head were a special target.

West set up pairs of model lions with short and long manes and watched to see which ones wild lions would approach. Males chose the short-maned dummy nine out of 10 times, she found, while females approached the darker-maned dummy, 13 out of 14 times.

West also found that the higher the testosterone level in the blood of male lions, the darker the mane. "Therefore, it isn't surprising that females would prefer darker manes and males would be intimidated," West said.

(Agencies)