How different are Polar Bears and Brown Bears behind the fur? As someone on a radio program recently noted, Polar Bears LOOK as if they have very long necks. Is this real -- would a Polar's neck look longer than a Grizzly's in a mounted skeleton -- or is it a matterof shorter (?) fur and/or habitual posture making a roughly the same length neck more visible?

Hi Allen,
Relative to Brown Bears of the same size, a polar bear is indeed more elongated. Good observation.

A decent, well-referenced Wikipedia article here. Scroll down to the section on physical characteristics for more onthe morphological differences
http://en.wikipedia.org/wiki/Polar_bear

A nice paper you can access on PLoS One discusses the changes to the skull
http://www.plosone.org/article/info:doi … ne.0013870

"Hope is a duty from which palaeontologists are exempt."
David Quammen