Sexy beast

Long, dark manes on male lions are more more attractive to females than shorter, lighter manes, researchers reported in today’s issue of the journal Science. Peyton West and Craig Packer of the University of Minnesota set up dummy lions with different mane types at Serengeti National Park in Tanzania. While males were more inclined to approach dummies with lighter, shorter manes, females were drawn to the dummies with big, dark hair. There’s good reason for this: blood tests revealed that males with darker manes tend to have higher levels of testosterone. But the most-wanted males pay a price for their looks: the dark hairs make the lions hotter, literally, and this extra heat results in a good deal of abnormal sperm.