“The enemy of my enemy is my friend.” This is what mother bears seem to think of the human being when it comes to defending the survival of their offspring against males of their species, prone to non-parental infanticide of cubs – that is, they end the lives of their cubs. others – so that the females are again available for mating.
Habitat selection is crucial to an individual’s survival and reproduction, and is something Swedish bears are well aware of, as they tend to settle near human-inhabited environments in order to protect their young. according to a study recently published in the British journal Proceedings of the Royal Society B.
They only do it during the mating period , since that is when the so-called selective sexual infanticide is triggered: adult males kill the cubs of others so that their mothers are available again for mating, so that in Instead of having to wait 18 to 30 months – that is the maternal care period – after the death of the offspring, the parents can be in heat again in just a few days.
The study, which covered 13,000 square kilometers of Swedish forest, was carried out with brown bears ( Ursus arctos ). The international group of researchers captured the females between 2005 and 2012 to put GPS collars on them and have them located. The habitat selection carried out by the bears helped predict the survival of the cubs: those that were successful in protecting their young established their residence an average of 783 meters away from humans (there were 16 females), for the 1,213 meters of average of those that did not obtain it (a total of 10).
We might think that bears actually move close to humans just to have easier access to their food scraps, and not so much in order to protect their young from adult males, but this is not the case, given that the quality of the mothers’ diet is worse when they move away from their usual environment .
Likewise, once the mating season is over, when the risk of infanticide is practically non-existent, females with young tend to return to share the habitat with their congeners and to avoid proximity with humans, since in these areas the Bear hunting (yes, only during certain periods, attending to a certain quota and always excluding groups of families).
