Alot of times the adult males will kill the cubs from other males so the females will go into heat and they can spread their genetic line...

stupid beast

probably got annoying. screw this i'm eating you!

It's been on the news ALOT lately. (yes I'm from Canada)
Some say it's because of global warming; the ice-pack breaks up sooner than regular and so the bears can't hunt the seals that make up their main diet. The bears' body masses are much lower than they have been in the past.
When you're hungry, cannibalism is a valid survival strategy. I'm inclined to believe this; the risk/reward for hunting bear cubs is MUCH higher than for any other food source (except people :)

ouch..

I too am from Canada, canibalism in bears has and always will be a fact.I have witnessed it in black bears near Lake Huron and it has nothing to do with global warming.Most hunters or people who live in remote areas see this all the time, but I can see how it attracts attention of busloads of tourists from the city out to see Polar Bears.
Given a chance, they will even eat you!
nature of the beast, hnce they are called wild animals
and life goes on

There isn't enough to know just from the pictures. The cub could be weak or injured and the bear made a decision to eat it instead of leaving it behind.

Don't compare black bears with polar bears. They live in VERY different geographical locations and each face their own unique challenges. (not to mention their relative population densities are extremely disproportionate)
Polar bears need the ice packs to hunt their prey, there is very little food for them on land. Regardless of your views on global warming, evidence shows that their accessibility to food has been dwindling.
Black bears on the other hand are not as restricted as polar bears (geographically and for energy sources) and feed primarily on vegetation, meat being a happy bonus.

So why haven't most of us seen or heard of black/grizzly/etc... bear cannibalism in the news?
NEWS! It's NOT a NEW observation for these bears, but it IS for polar bears.
The fact remains that we don't know all the conditions that led to these pictures, but as it is news, we have a responsibility to understand more. I trust the scientists (much more knowledgeable than myself or any other commentator here) that have put forward their interpretations - they might be wrong, but they do have data to back it up.

ooo come on! it is absolutely normall thing in nature to happen

I too am from Canada, and know for a fact that black bears and polar bears are the same thing.

im hungry...

These photos were taken near Churchill, Manitoba. There have been 4 confirmed cases of canibalism by male polar bears. The reason for this is due to the fact that it was an unseasonably warm fall, the ice in Hudsons bay has yet to freeze. The main food source for polar bears is seals (hopefully baby ones) that are out in Hudsons bay.

gnarlly

David,
David,
DY,
Daedalus,
Pepe

ummmm none of my comments showed up!!
shit!!!!!!!!!!!!!!!!!!!!!
i am not typing all of that again