By comparing female baboons' rumps, a male can spot those potential mates best suited for motherhood, say researchers in England.
In females of about 10 percent of primate species, bare areas of their rears swell as they near ovulation. In olive baboons, Papio cynocephalus anubis, water retention in posterior tissues can add 12 percent to a female's weight.
For indicating motherhood potential, bigger means better, report Leah G. Domb, now in Bristol, and Mark Pagel of the University of Reading. They found that wild females with the biggest bulges give birth at earlier ages and see more of their young survive than do females with smaller attributes.
Males seem to get the idea. In Tanzania's Gombe National Park, they threaten each other and get into fights more often ov