Lion Manes Are Just for Show

A lion’s mane may look like a shaggy security blanket, but new research from the plains of the Serengeti shows the long locks offer no protection when two rival males fight for the chance to mate. The study suggests the male lion’s mane serves mostly as a lioness magnet, and played an important role in the way male fighting strategy evolved.

The purpose of the male lion’s mane has long perplexed biologists. Because female lions roam in groups of three or four, and allow only one male to reside with them, competition between males is fierce. Rival males often fight to the death—with their enormous teeth and claws—to gain coveted access to a pride. This led many biologists to assume that the function of the thick manes was to make it harder for attackers to reach the vulnerable throat area. But over the years this assumption has been questioned, because field biologists who actually saw lion fights in action noticed the mane area was rarely targeted.

Evolutionary biologist Peyton West and her colleagues from the University of Minnesota used life-size lion dummies to test if manes indeed offered protection. The researchers first lured some big cats to the testing area by playing tapes of hyenas feeding at a kill, then presented them with the fake rivals. “Of course we worried that the lions wouldn’t be fooled,” West says. But many of the real lions attacked the fakes with a vengeance. (Sometimes the fakes worked so well, in fact, that even after the real lions knocked them over, according to West, “they tended to stick around and maul them some more.”)

The real lions attacked the models not at the neck, but on the back and hindquarters, putting a serious snarl in the protective mane hypothesis. To see if the males were avoiding the neck because the mane was acting as shield, the researchers repeated the tests with “maneless” fakes. But even with these exposed-neck models, the real lions went first for the backside. “We were pretty surprised to find so little evidence for protection,” West says, because “it’s so intuitive that the mane would work that way.”

But it turns out those shaggy manes are used for attracting females. In previous research published in 2002, West had shown that males with longer and darker manes were older, better fed, and better fighters. And because females rely on males to protect their cubs, it makes sense that females would prefer males with large manes. “Just as songbirds can advertise their quality though visual cues, so, apparently, do lions,” says field biologist Jon Grinnell of Gustavus Adolphus College in Minnesota. Grinnell says West’s study is “new and interesting, because it forces us to look at lions differently.”

Even though manes don’t offer protection now, West says a protective role could have been the reason the trait evolved in the first place. In the early evolution of the trait, she says, males may have gone straight for the neck, making individuals with manes harder to attack and thus more favored by natural selection. As evolution continued and more and more males developed manes, attacking the neck area would no longer have been an effective fighting strategy—leaving our modern lions with manes.

“The lion is an intensively studied species and probably the best known wild cat on earth,” says field biologist Luke Hunter of Wildlife Conservation Society-International, “but this study shows that good science is still revealing new things about the species and turning over popular misconceptions.”

Journal reference: Animal Behaviour, March 2006 (vol 71, p 609)

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