For Immediate Release The Field Museum, Greg Borzo (312) 665-7106 gborzo@fieldmuseum.org Lion mane linked to climate Field Museum scientist studies zoo animals across U.S., results tie manes to cold weather for first time Manes cover more of the lion’s body than just the head and neck. For this study, researchers identified 11 mane fields: throat, forehead, upper neck, sideburns, chest, shoulders, sternum, ribs, belly, elbows and dorsal crest. They compared the length and density of these 11 mane fields for all 19 lions. These lions live at the Caldwell Zoo in Tyler, Texas. CHICAGO—If you were a male lion and could read the latest scientific research, you would want to move to a warmer climate, where your mane would be more impressive. That is, until it started getting smaller, to fit you to your new warmer climate! It’s long been known that lions with long, full manes get the girls. Now, an innovative study based on zoo animals all across America shows for the first time that cold temperatures help the king of the beast grow his mane long and thick – and more appealing to potential mates. In fact, up to one-half of the length and density of a zoo lion’s mane can be attributed to temperature, rather than nutrition, social factors, individual history, or genes, according to a study that will be the cover story of the April issue of the Journal of Mammalogy. That journal will be published on April 13, 2006. Dense manes retard heat loss as would a scarf or fur hat. Zoo lions in hot climates adapt with smaller, thinner manes. Those in northern zoos never overheat so no reduction in their mane is necessary. Those in southern zoos occasionally overheat, so a differential hair growth rate keeps their manes relatively thinner. These differences in mane conditions are not the result of natural selection. Rather, they are a sign of a flexible trait that can vary to match local conditions. Like a buck’s antlers or a peacock’s tail feathers, the lion’s mane primarily serves to attract females and intimidate male competitors. But it comes with a cost: a full mane takes energy to grow and maintain; gives away location to prey; makes maneuvering through bramble difficult; harbors parasites, and, as we have said, retains heat. Overheating explains why lions in colder climates have longer, thicker manes: the heat-retention cost of a full mane is less for lions in cold weather conditions than it is for lions in hot weather conditions. “While a big mane impresses everybody, even a small mane can be imposing in hot dry climates, where the costs of overheating are great and most male lions have little or no mane. This is the case in Tsavo, Kenya, where most lions are maneless,” said Bruce D. Patterson, PhD, the MacArthur curator of mammals at The Field Museum and lead author of the research. He and his colleagues began studying manes due to their research on the infamous maneless Tsavo lions. Dr. Patterson is the author of The Lions of Tsavo (McGraw Hill, 2004), which tells the story of the man-eaters. At the end of the 19th century, two Tsavo lions set upon railway crews and ate as many as 135 people (by some accounts) before they were finally hunted down and killed. Those two lions have been on display at The Field Museum since 1925, and are the subject of a major motion picture staring Michael Douglas and Val Kilmer called “The Ghost and the Darkness” (Paramount, 1996). While their man-eating habits have garnered most of the headlines, the maneless condition of these adult male lions is even more curious. Continue>>