Doting Baboon Dads Get More Grandkids

Feb. 4, 2008 -- Polygamous male primates aren't exactly famous for their fathering skills, but a new study has found that baboon dads matter, to the point where their presence and care can physically change their sons and daughters for the better.

When dad's around, yellow baboon offspring begin their reproductive lives earlier, allowing them to reward their father with more grandchildren in future.

The discovery suggests that paternal presence could be important for all primates, and perhaps for all polygamous mammal societies.

Dad especially comes in handy when fending off bullies, co-author Susan Alberts told Discovery News.

"If a baboon kid is in danger, it may scream or make eye contact with its father," she said. "It's very obvious, even to human onlookers, what is meant. It's as though the young baboon is saying, 'Help me! Help me! This individual is attacking me.'"

"It's not unlike human parents who hear their kids screaming," added Alberts, an associate professor of biology at Duke University.

Good fathers can also indirectly fatten up their offspring by overseeing wider patches of territory for foraging, determined Alberts and her colleagues. To arrive at that conclusion, the researchers analyzed 30 years worth of data they had collected on 40 males and 78 females from wild yellow baboon groups living in the Amboseli basin at the foot of Africa's Mount Kilimanjaro.

The researchers specifically focused on the age of physical maturation, a good measure of fitness in most primates. Humans are somewhat different, because kids with very attentive parents usually mature more slowly than others.

Among baboons, daughters with supportive fathers reached menarche, the onset of menstruation, earlier. Sons with such fathers also experienced testicular enlargement earlier, but only if their father was a highly ranked individual in the baboon's tight knit group.

"For young females, because their major opponents in life are adult females and fellow juveniles, the presence of any male may be helpful," Alberts explained. "But for maturing sons, it may be that it's not really the females they're dealing with; it's the adult males they have to worry about. In that case, only the presence of a high-ranking dad would be helpful."