How the Giraffe Got Its Neck

Darwin was the first to propose that long necks evolved in giraffes because they enabled the animals to eat foliage beyond the reach of shorter browsers. That seemingly sensible explanation has held up for over a century, but it is probably wrong, says Robert Simmons. Simmons, a behavioral ecologist at the Ministry of Environment and Tourism in Windhoek, Namibia, believes giraffes developed long necks not to compete for food but to win mates. Simmons was studying eagles in Sabi Sand Reserve in South Africa when he happened to come upon a pair of male giraffes locked in combat. Male giraffes battle for mates by swinging their powerful necks--which can be over six feet long and weigh more than 200 pounds. The momentum generated allows them to slam their heads into their opponents with vertebrae-shattering--and occasionally lethal--force. In these contests, males with the longest, thickest necks usually prevail. As Simmons watched ...