In Many Species, a Family Dinner Means Something Else
▻https://www.nytimes.com/2017/01/30/science/cannibalism-animal-biology.html
Until relatively recently, the party line among scientists was that cannibalism occurred in only a few species in the wild, like black widow spiders and praying mantises. Cannibalism, researchers felt, was an aberrant behavior resulting from a lack of alternative forms of nutrition or the stresses associated with captive conditions.
But over the decades, evidence has been gathering for an alternative view. Cannibalism, it turns out, occurs in hundreds of species, perhaps thousands. The behavior varies in frequency between major animal groups — nonexistent in some, common in others. It varies from species to species and even within the same species, depending on local environmental conditions.
As important, the behavior serves a variety of functions, depending on the cannibal, and some of these have nothing to do with stress or captive conditions.