Did they die because the polar bears ate them?
BTW - The deaths are an estimate. This raises my BS Flag. Whenever I see the word “estimate” these days I substitute it with “made up.” I may not be right every time but chances are very good I am most of the time.
Let me give you more reason to raise the BS flag higher.
From the article - "A Russian biologist estimates that as many as 4,000 walruses out of a population of some 200,000 died this year, a death rate that's two or three times the usual number."
If 4000 walruses die every year in a population of 200,000, that means the life expectancy for a walrus is 50 years.
But if that 4000 is 2-3 times the "normal number" then with normal numbers of deaths, the life expectancy for a walrus is 100-150 years.
The unnamed scientist is obviously full of crap.