It's a good way to get lipids

Quoting from the New York Times, May 9, 2006:

A hungry mother can be the stuff of nightmares — especially if it is the mother next door. Chimpanzees are exemplary mothers when it comes to caring for their own, said Sarah Blaffer Hrdy, a primatologist and the author of "Mother Nature: A History of Mothers, Infants and Natural Selection."

Unlike humans, Dr. Hrdy said, the apes never abandon or reject their young, no matter how diseased or crippled a baby may be. Yet because female chimpanzees live in troops with other nonrelated females, a ravenous, lactating mother feels little compunction about killing and eating the child of a group mate. "It's a good way to get lipids," Dr. Hrdy said.