Why Baboons Are Killing Offspring

Image: Belgianchocolate, Flickr

Research shows that not only do male baboons commit infanticide in order to more quickly reproduce with mates — they engage in feticide as well.

Baboons are ground-dwelling primates that typically inhabit open woodland and grassland ranges across Africa. Most of these animals live in hierarchical groups averaging fifty individuals and all members strictly adhere to established dominance relationships between males.

Historically, baboons, lions, and dolphins have all displayed intermittent incidents of infanticide in order to expedite individual breeding cycles. Baboons are most prone to this behavior and males will occasionally kill a female’s nursing infant in order to more quickly restore her to fertility thus enabling him to breed with her and produce offspring of his own.

Research on baboons in Amboseli National Park, Kenya revealed that the behavior exponentially increased among groups of baboons containing less numbers of fertile females. The most surprising aspect of the study showed the baboons were not only committing infanticide — but feticide as well.

Image: Richard Bartz, Wikimedia Commons

It was confirmed that not only will baboons kill nursing offspring of other males, but they will also attack pregnant females and cause them to miscarry. What were previously considered to be outlying incidents of interpersonal violence are now scientifically identified sexual behaviors.

While males typically have to wait one year before a pregnant or nursing mother is ready to conceive again, killing a nursing infant or forcing a miscarry shortens this time period to an average of forty days.   

“In situations where males have few opportunities, they resort to violence to achieve what’s necessary to survive and reproduce,” author and graduate student Matthew Zipple reported to Science Daily. “When reproductive opportunities abound, this behavior is less frequent.”

The complete study is published in the Proceedings of the Royal Society B.