Abstract by Emily Herdman

Sexual Selection, Temperature, and the Lion’s Mane

Peyton M. West and Craig Packer

The authors were investigating the influence of temperature and sexual selection on the darkness and length of manes in male lions ( Panthera leo). To accomplish this, they determined that darkness is influenced by testosterone, age and nutrition and that length indicates fighting ability and short-term health. To investigate the effect of sexual selection on manes, they did choice experiments with females to determine preference. They found that females preferred males with darker manes. Females benefit from such choice because dark-maned males tend to be better protectors/provisioners of cubs (with the exception of the Serengeti plains), better fed and more mature. Females did not show preference for longer-maned males. The authors also found that males use mane length and colouration to determine fighting ability and always approached males that had manes of a lighter colour and usually of a shorter length. Thus male mane darkness influences male-male competition. Despite these interesting results, the authors found that temperature is the most influential environmental variable influencing mane darkness and length. Males with conspicuous manes were found to have higher body temperatures resulting in increased cases of abnormal sperm and a decrease in feeding rate during the hotter months to reduce body temperature. Overall, sexual selection is unlikely important in determining mane darkness because it is not an inherited trait.