Why does infanticide occur in animals

The prevailing adaptive explanation for the behavior, however, has been the sexual-selection hypothesis according to which males increase reproductive opportunity by killing unrelated, unweaned offspring, thus hastening the mother's next ovulation, at which time the infanticidal male can mate with her [9]. Alternate nonadaptive explanations such as social-pathology and side effect hypotheses have also been proposed.

Males in primate groups often exploit infants to which they are not related in ways that lead to the death of the infant. Maternal infanticide, although very rarely observed in non-human primates, has been considered as a way of paternal manipulation to end investment in certain offspring. However, the study indicates that the mothers likely did not kill their offspring to exploit the meat.

On the other hand, the evolution of nonparental male infanticide has often been explained by the sexual selection hypothesis, which posits that infanticide improves male reproductive success by shortening the interbirth intervals of the mothers of the killed offspring. The sexual selection hypothesis is supported by findings that indicate that infanticide mostly occurs in social species, less in solitary species, and least in monogamous species since according to the sexual selection hypothesis, infanticide would be most adaptive in stable bisexual groups where a few males monopolize reproduction over short periods of time [7].

In social species where a few males monopolize reproduction over short periods, killing the offspring of males who had previously been monopolizing reproduction would be adaptive for the individuals committing infanticide. In monogamous species, since pairs of reproducing adults live together with their offspring their whole lives, male infanticide of unrelated infants would not be as adaptive for individuals.

In , a study described the killing of a one-month old marmoset , the daughter of the dominant female, by the second breeding female in the group. This female made the attack while she herself was pregnant. Later, she gave birth to twins and appeared to become the leader of the group. While the marmoset appears chillingly cold-blooded to us, the move was clearly made out of a primal urge to secure the best possible future for her offspring. Huchard and Dieter Lukas at the University of Cambridge recently published a study of female infanticide in mammals.

The work is yet to be peer-reviewed, but it has helped to document the prevalence of killer mums in mammalian societies. Females will kill whenever they can assess clear benefits from doing so. Environment Planet Possible India bets its energy future on solar—in ways both small and big Grassroots efforts are bringing solar panels to rural villages without electricity, while massive solar arrays are being built across the country.

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