E-Bear, do bears always use the same den, or do they dig a new one each year ( different region etc. )?
Sylvia, it depends on the den. Some caves appear to have been used repeatedly overtime. The coastal bears we see on the WildCam generally excavate their dens on a slope under alder roots. The alder roots hold the soil, but maybe only for one denning season. They may collapse and not be usable a second time.
I learned that bears in sanctuaries are not true hibernators. They sort of wake up, do some stretching, rearrange their beds, even wander around a little bit, then go back to sleep again. Do bears in the wild act like that, too?
Some people claim that bears, in general, are not true hibernators because although they lower their heart rate and lower their metabolism, they do not lower their body temperatures so low that they go into a torpid state. Here are some notes about how much they do these things... heart rate drops from 40-70 beats per minute to about 8-12 beats per minute
metabolism slows down by half
body temperature drops only slightly by 3-7degrees C to (5-9degrees F)
if a bear’s body temp drops below 20dC 68dF it has a cardiac arrest
Sylvia, the stirring you are describing has been observed in brown bears. It's one of the reasons brown bear denning is dangerous to study. Brown bears will charge if disturbed. Mother bears wake up during the birth of their cubs.
heart rate drops from 40-70 beats per minute to about 8-12 beats per minute
metabolism slows down by half
body temperature drops only slightly by 3-7degrees C to (5-9degrees F)
if a bear’s body temp drops below 20dC 68dF it has a cardiac arrest
Sylvia, the stirring you are describing has been observed in brown bears. It's one of the reasons brown bear denning is dangerous to study. Brown bears will charge if disturbed. Mother bears wake up during the birth of their cubs.
heart rate drops from 40-70 beats per minute to about 8-12 beats per minute
metabolism slows down by half
body temperature drops only slightly by 3-7degrees C to (5-9degrees F)
if a bear’s body temp drops below 20dC 68dF it has a cardiac arrest
Sylvia, the stirring you are describing has been observed in wild brown bears. It's one of the reasons brown bear denning is dangerous to study. Brown bears will charge if disturbed. Mother bears wake up during the birth of their cubs.