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Within the Black Bear population,
a small percentage makes a significant contribution towards producing
young. Twenty-five percent of the females in the study produced 66% of the
litters. The characteristics of these super mothers were:
- permanently established home ranges
- above-average size and weight,
longevity
- low vulnerability to mortality
including hunting
They were nearly always accompanied by
cubs and therefore not legally hunted.
Black bears have one of the lowest reproductive rates of any North American
land mammal. They have a comparatively slow reproductive maturity, prolonged
reproductive cycle and relatively small litter sizes. However, some black
bear populations have increased at rates as high as 25% annually . Some of
the reasons are related to the limited mortality of cubs between 0.5 and 1.5
years due to maternal care and the precocious nature of cubs of this age.
Nutrition has been related to cub survival, but losses of entire litters to
starvation are not common.
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