If you've always wanted to crawl into a polar bear's winter den

Via The Siberian Times:

Up to 500 mother bears a year give birth on remote Wrangel island, also the last place to see woolly mammoths. 

Researcher Leonid Zaika spoke to The Siberian Times to share his experience of surviving a face to face meeting with a furious mother bear whose den he went to explore after wrongly calculating that it was empty, of seeing bears gathering under kitchen window because they like smell of milky porridge, of some predators that attack but others that ‘wag their tails’, and studying their maternity dens...

‘After cubs are born, mothers take them away from the ‘maternity dens’ to teach hunting and other key survival skills, and never come back. Our task is to catch the moment when a family leaves a den so that we can crawl inside it, study the delivery chamber and pick up biological material like hair and food derivatives,’ the researcher said. 

This information is needed to understand if animals were comfortable while they stayed inside, if a mother bear was peaceful or irritated. 

A comment at the site worth noting: "...the Wrangell Island entry at Wikipedia clearly states that it is not to be confused with Wrangel Island, which is an island in the Arctic Ocean between Chucki sea and East Siberian sea.  Wrangel Island was declared a Zapovednik in 1976. This strictly controlled (and rightly so) nature reserve is one of Russia's most treasured wildlife sanctuaries... And must, at all costs, remain so... "

Awesome claw marks on the walls and ceiling.  I wonder how the mothers sense the horizontal depth of the snow, to know that their tunnel won't end after a couple meters at stone.