Lions and leopards aren’t the biggest mortal threat to baboon babies, as you would be easily led to believe. When it comes to Chacma baboons, large and aggressive southern African monkeys, it is the adult males of the same species that represent the most important threat. Consequently, nature, in its wise way, came up with the perfect countering mechanism. Mothers defend their young in a most unique way: promiscuity.
“Up to 50 percent of the infants might be killed by males in these populations, a massive impact more important than disease or predation,”
Dieter Lukas, University of Cambridge behavioral ecologist said.
However, this behavior is certainly not limited to baboons, scientists explain. A detailed study on infanticide among adult male monkeys was unveiled on Thursday, showing that the practice is numerous in various species. Researchers took 260 species and examined the way that adult males interact with other females’ offspring. Among these 260 species, 119 practice infanticide while 141 do not.
Researchers then attempted to search for patterns explaining this behavior which is rarely seen in non-mammals.
Else Huchard, of the National Center for Scientific Research, Center for Evolutionary and Functional Ecology in France, explains that this behavior is most likely a sexual strategy. According to Huchard, infanticide is most often the adult male’s way of making the mother of the newly-murdered infant available for mating. She adds that approximately 25 percent of mammals practice infanticide.
Chacma baboons , as many other mammals practicing infanticide, live in groups where reproduction is often monopolized by several males that only hold their dominant position for a restricted amount of time due to many challengers. On the other hand, with monogamous mammal species, infanticide is rare.
“Infanticide rates across all the mammals they looked at were lower in monogamous species than in any other social group. That supports our paper back in 2013, when we suggested that monogamy was quite an effective response to infanticide.”
Christoper Opie, researcher with the University College London said.
In some cases, females of specific species strategically use promiscuity as a way of keeping other males from killing their offspring. They mate with as many males as possible in the shortest amount of time so that discerning infant paternity is impossible.
“Males stop killing offspring if there is a risk that the offspring might be their own,”
Infanticide was observed rarely in species reproducing seasonally, as there would be benefit for males to wait for the next breeding season for females to become fertile.