For Immediate Release The Field Museum, Greg Borzo (312) 665-7106 gborzo@fieldmuseum.org Unique social system found in Tsavo lions Individual males rule large prides CHICAGO—Tsavo lions, famous for man-eating at the end of the 19th century, are also novel for being maneless. Now, the first scientific peer-reviewed study of the ecology of Tsavo lions reveals that they have a unique social system. Tsavo lions are the only lions known to live in large groups of females ruled by a single male. The scientists surveyed the lion population of Tsavo East National Park in eastern Kenya, documenting the size and composition of each group and the condition of manes on males. The five resident groups of females they documented had an average of 7.4 adult females per group, large for prides in general. However, each was attended by only one male rather than a coalition of two-to-four males, typical of large prides elsewhere. “Although the lion is one of the world’s best-studied mammals, no one has documented undisturbed groups of seven-to-eight adult females with a single adult male,” says Roland Kays, PhD, co-author of the research to be published online April 11 by NRC Research Press’ Canadian Journal of Zoology. Most of what we know about lions comes from studies conducted in the thriving grasslands of the Serengeti Plains in Tanzania where lions are surrounded by teeming herds of game, and lone males are quickly deposed by coalitions of males that rule prides in unison. In George Schaller’s classic study, The Serengeti Lion, none of the 12 prides he studied had lone pride masters. But the well-studied Serengeti lion may not be representative of the species as a whole. In fact, in historic times the lion ranged over an incredibly vast geographic area, from South Africa to the Balkans, from Morocco to western India. To exploit such a diverse array of habitats, lions must have adapted many different lifestyles and behavior patterns. “How does Panthera leo behave in markedly different habitats and climates?” asks the study’s co-author Bruce Patterson, PhD, MacArthur curator of mammals at The Field Museum. “Studying lions in Tsavo indicates that the ‘king of the beasts’ has a lot of tricks up its sleeve that confuse and astound those who would type-cast it.” Continue