Good gorilla Dads

Well, if you overlook the infanticide they might commit before having their own kids, at least.  Science reports:

A few years ago, four female mountain gorillas left home, abandoning not only their mate—a sick alpha silverback—but their infants, which were barely old enough to feed themselves. They may have sensed that their offspring would be safer with their ailing father than with new males that often kill infants from other groups. Still, most mammals abandoned by their mothers risk an early death, and researchers worried about the young gorillas.

Instead, the scientists got a heartwarming surprise. The juveniles’ uncle, a male gorilla named Kubaha, began to take care of them. “He let them sleep in his nest and climb all over him like a jungle gym,” recalls primatologist Tara Stoinski, chief scientist of the Dian Fossey Gorilla Fund.

Kubaha’s willingness to be a foster dad turns out to be surprisingly common in mountain gorillas, according to a new study. An analysis of 53 years of data on mountain gorillas at the Gorilla Fund’s Karisoke Research Center in Rwanda has revealed that when young mountain gorillas lose their mothers—and sometimes their fathers as well—they do not have a greater risk of dying or losing their place in the social hierarchy because the rest of the group buffers them from the loss.....

The study is “terrific,” says Duke primatologist Anne Pusey, who was not part of the work. The data come from one of the longest mammal field studies, she notes, and the number of orphaned gorillas is high enough to compare directly with data from young chimps. Those data show that chimps die young or suffer other ill effects if they lose their mothers because females don’t change groups often—and infants are more dependent on their care longer than are gorillas.

Now, researchers need to comb decades of data for bonobos and other species to see whether they, too, adopt motherless infants more often than believed, Zipple says. A study published last week found that two bonobo females adopted infants from another social group in the Democratic Republic of the Congo.

The findings suggest such altruistic behavior is not unique to humans—and that dads play an important role in primate youngsters’ lives, says Duke behavioral ecologist Susan Alberts, who was not part of this study. “Nonhuman primates often are really good dads,” she says. “This shows that paternal care goes very deep in our primate lineage.”