Bears and hibernation

[Robin Leech]

Fellow taxaxomers,

As a spiderologist, I do not keep up with all the latest on
the views about whether bears hibernate or not.  Having
said that, I was under the impression that bears do not
really go into hibernation, as their heart beat rate and
body temp do not change much, but instead go for several
short snoozes.

Thus, my question is this: do bears actually hibernate,
or do they simply avoid the coldest periods by being in
a den?  I do know that an anal plug is formed, but this
does not constitute a necessary part of a true hibernation.

Robin Leech