Bear moms seek human help to halt killer mates

Some young bear mothers live closer to humans for the duration of the mating season when male bears, called boars, go into frenzies of lust-fuelled cub killing.

But motherly instinct seems to trump sex drive. While sows grin and bear the threatening human proximity for the sake of their offspring, boars continue to give humans a wide berth.

"Bears in general avoid areas close to humans," said Sam Steyaert of the Norwegian University of Life Sciences, who co-authored the study.

"A fter the mating season females with cubs go back to avoiding humans."

Male brown bears kill cubs to trigger oestrus, a period of sexual receptivity, in females that would otherwise come into heat only after raising their cubs to independence. Instead of having to wait 18 to 30 months, the males "can obtain a mating opportunity in just a few days", Steyaert said.

The behaviour is called sexually selected infanticide.

Steyaert's team tracked 26 mother bears between 2005 and 2012. Of the sows, 16 raised cubs and 10 failed.

"Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans," the study concluded.