These monkeys could win dad of the year

Mother owl monkeys' primary interaction with offspring is nursing. It's the dads that carry, play, and nurture the babies. They're also the ones most likely to retrieve and hold offspring when there is perceived danger. (Credit: Steve Harris/Flickr)

The natural world’s finest fathers might just be covered with fur and live in the trees of Argentina.

Male owl monkeys do a good portion of the nurturing, child-rearing, and protecting of offspring, researchers say.

“These fathers play, groom, share food, and transport infants more than the mothers,” says Eduardo Fernandez-Duque, a professor at Yale University who has studied owl monkeys in their natural habitat for nearly two decades.

“We have found that owl monkeys are the first of any primate species, and only the fourth pair-living mammal, to show genetic monogamy, or real faithfulness, between partners.”

Monogamous monkeys

Fernandez-Duque and his wife, biological anthropologist Claudia Valeggia, set up a field site in northeastern Argentina on 170 acres of forest within a 62,000-acre cattle ranch in the Chaco region. Since 1996, the Owl Monkey Project has produced a wealth of research on the social habits of the small, arboreal primates.

Argentinian owl monkeys weigh about three pounds, have large, brown eyes, make a wide range of vocal sounds, and are active both at night and during the day. They are also called night monkeys.

Detailed tracking and genetic data suggests that the monkeys are both genetically and socially monogamous. Although female owl monkeys sometimes take on a new male partner, females that are able to preserve a monogamous relationship produce 25 percent more offspring.

Dad is the ‘fun one’

Owl monkey fathers shoulder at least as much, if not more, of the parenting duties as owl monkey mothers do, researchers say. While the mothers’ primary interaction with infants involves nursing, it’s the dads that do much of the carrying and playing. They’re also the ones most likely to retrieve and hold offspring when there is perceived danger.


One key to owl monkey monogamy may have to do with food, Fernandez-Duque says. Primary food sources are spread out geographically in small clusters, with enough to sustain only one female. Males tend to stay close to only one female, and fiercely guard the shared territory with the females.

As social monogamy evolved among owl monkeys, the close bond between males and females aided in the development of genetic monogamy. The males’ involvement in childrearing helped females recover from pregnancy more quickly and gave offspring a better chance for survival.

“Ready access to genetic testing these days is helping us solve a traditional puzzle in evolutionary biology: Why are some male mammals monogamous, and why do some of those males invest so much on infants they do not know if they have sired?” Fernandez-Duque says.

“We think this is a possible explanation for one of the most remarkable dads in the animal kingdom.”

Source: Yale University