"Stay at Home" Baboon Dads Raise Healthier Kids
for National Geographic News
|February 5, 2008|
Young baboons with "stay at home" dads are healthier and mature more quickly than their peers, a new study says.
The effects are particularly pronounced in daughters, though Duke University primatologist Susan Alberts isn't sure how it works.
"Dads may be somehow enhancing their kids' nutritional status by [boosting] their [offspring's] ability to get food," said Alberts, senior author of the new study.
"It's also possible that by intervening on behalf of their kids, they are reducing their kids' stress levels."
No Deadbeat Dads
Paternal care is relatively rare among mammals. Because yellow baboon mothers are typically seen caring for their young, the same was thought to be true of that species.
"Females often mate with multiple males, so we used to think that males didn't have any way to know who their offspring were," said Joan Silk, a UCLA anthropologist unaffiliated with the new research.
"It turns out that we were probably wrong."
The researchers used data from studies of yellow baboons living in Kenya. They found that the more time fathers spent with their daughters, the faster the daughters reached menarche, the onset of menstruation.
Sons also matured more quickly if their fathers hung around, but only if their fathers were high-ranking at the time of their birth, the researchers added.
(See a picture of a baby baboon.)
In previous studies of baboons in Kenya, Alberts and colleagues took DNA samples that revealed many infants grow up in groups with their fathers. The researchers also found that those fathers routinely intervened in disputes to stand up for their kids.
Typically, species in which dads play a major role in parenting are also those where couples pair up for the long-term, such as siamangs—a type of gibbon—and owl monkeys.
(Related news: "Monkey Dads Gain Weight With Their Mates, Study Says" [February 6, 2006].)
But baboon dads appear to get involved because their effort pays off for their offspring.
The study appears this week in the journal Proceedings of the National Academy of Science.
It Pays to Parent
Daughters born to high-ranking moms mature earlier—a lifelong advantage—and during their lives typically give birth to half an infant more on average than other females.
(Related news: "Baboon Study: Sociable Moms Have Healthier Young" [November 13, 2003].)
"We're thinking that the effect of the fathers' [influence may be] similar," study author Alberts said.
Elizabeth Susman of Pennsylvania State University suggests that the role stress reduction plays may be linked to the endocrine system.
"When you reduce stress, you increase the probability that reproduction would occur," Susman explained.
"If you're under high-stress conditions, your sex steroid hormones are suppressed, which would delay puberty."
Susman also pointed out, as did the new study, that many studies on humans find children raised in homes without a father present actually reach sexual maturity faster.
"It has been found in a number of studies ... [but] there is no explanation that has worked across all studies," Susman said.
It's also unknown how baboon dads produce the opposite effect, said UCLA's Silk.
But researchers now know that baboons consider parenting to ensure survival of their offspring important, she said.
"Now people will go back and ask how and why males have this effect," she said. "[Until] now you wouldn't have asked this question—and it's a really relevant question."
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