How climate change is driving polar bears to extinction

Another disturbing effect of climate change — polar bears are eating their cubs.

Transcript

00:00Yes, they are talented swimmers, but they cannot swim 400 kilometers to go explore and

00:17find mates or even to find food. When a population reaches carrying capacity, you will find that

00:36there will be some cannibalism, but you're also looking at another process of cannibalism,

00:43which we call infanticide. It's a strategy that the species uses for male reproductive success.

00:51So you will find that without sea ice, there's a limited number of mates. So the competition is

00:58fierce. As a male, you would want to pass your genes. If a female loses her cubs and immediately

01:04becomes receptive to actually conceive and produce another litter, then that, of course, males would

01:11hunt and then kill offspring to ensure that the female would reproduce and, of course, pass on their genes.

01:29It's relatively a small population, so there is some order of genetic relatedness.

01:33So on average, what you're seeing is that individuals that are closer together are mating,

01:39and that could unmask some of the genetic, some of the

01:43recessive traits in the populations, which are detrimental.

01:56We had found there was that there was between a 3 to 10 percent

01:59loss in genetic diversity as time progressed, because sea ice is that connection, is that bridge

02:05that connects different habitats or different areas. Without that, you will find that the

02:13population of the gene pool becomes so small in the different areas that some areas where you

02:18would typically find bears, you would never find them again. If you do not have that reservoir to

02:24ensure that individuals are different enough, if there's an outbreak of a disease, you might not

02:29have individuals that would be resistant to it. The capability of a species to evolve and to

02:34withstand whatever nature throws at it, without it, it's basically doomed for extinction.

02:47Areas that were once connected are gradually now becoming isolated. If the trend is not basically

02:54halted, then what you will see is that you will lose a substantial amount of populations in the

02:59region.

03:20As the population is recovering, then, oh my God, then climate change was being reported.

03:26Now, it's literally climate that they are facing. That's a major threat to polar bears now,

03:32is climate, the warming temperatures. We are really destroying a habitat of a species here.

03:38As time goes on, and with our work as well, with the predictions that we had made,

03:43I really do hope that we never get to see those come into fruition.