Cannibalism and infanticide is one of the dark sides of nature and it is not uncommon in many species, but scientists report an increase in polar bears feasting on cubs and females in recent years.
One scientist says polar bears, the largest of the bear species, do it “just because they can.” Dr. Susan J. Crockford is a zoologist, who claims polar bears kill each other for a number of reasons. She wrote on her website
“Male bears kill newborn cubs in the spring to bring females into estrus – so that they are able and willing to mate again with the new male (this only works until perhaps early June at the latest); 2) females may eat their young (probably at any time of year) when they can’t get other food; 3) males will kill adult females, smaller bears and cubs at any time of year and eat them – whether they are thin or fat, truly hungry or not – just because they can.”
Dr. Ian Stirling of Environment Canada has been studying polar bears for more than 40 years and he believes early ice melts are the cause of more cannibalism reports. Ice floes melt in summer, with many disappearing totally, making hunting for the bear’s favorite food of seals more difficult, which forces them to roam further and settle for less; like sea birds and their eggs.
“From his lying position in death the bear appears to simply have starved and died where he dropped,” Stirling said. “He had no external suggestion of any remaining fat, having been reduced to little more than skin and bone.” Furthermore, ships have occasionally spotted polar bear bodies floating at sea after apparently drowning; most likely while swimming in search of solid ice after being trapped on melting floes. Since drowned bears eventually sink to the ocean floor, it’s hard for scientists to know the extent of this problem. Polar bears are massively skilled swimmers, but in poor fitness they are more vulnerable.
Regardless of the “common” claim by many to explain cannibalism in polar bears, others feel that “common sense” should figure into the equation when polar bears are facing a mortal scarcity of food due to a melting habitat. Many experts feel polar bears could be virtually extinct in the next 50-100 years if climate change stays on its current path.