I''ve heard a theory that a polar bear, when hunting, will place one of their front paws in front of

I've heard a theory that a polar bear, when hunting, will place one of their front paws in front of their nose while stalking their prey, so that they are completely camouflaged. Is this true, and is the reality as funny as the mental image?

Maria Lamle, London UK

• Its a great theory, but sadly untrue. Seals, which make up the bulk of polar bear diet, are very short-sighted on land, their eyes being better adapted to seeing underwater. They compensate for this by a very well developed sense of smell. While an adult bear would be difficult to miss, the bear's nose alone would not present a visual warning for a myopic seal. However, the smell of the bear (better imagined than experienced, I can assure you) would alert the seal to his presence, even if he was approaching from down-wind. In response to your second question, regarding funny mental images - imagine a 2-ton fully-grown adult male polar bear, lumbering across the floe towards a hole in the ice, wherein is a seal. The seal ducks back below the water to avoid the bear. The bear will shove his head into the hole in order to make a grab for the seal. So, the bear's head is at rest. Unfortunately the rest of his body is in motion, and is unable to gain traction on the ice. Thus what you see is the back 2/3rds of the bear sliding across the ice before hitting himself in the chin with his own behind. Insert sound effects.

  Paul Sampson, US Parks Service, Fairbanks, Alaska USA