IdaRam
AH legend
Going along hand in hand with the excellent points Van and Jeff have already made, you also have to take into consideration some additional factors that influence the size of bears in Idaho. One is known as “negative foraging period”. In much of Idaho it can be tough for a bear to make living and in many areas of the state (not all, but most) from the time a bear emerges from its den in the spring it continues to lose weight for a month or two. The forage available is not nutrient dense until some time in July or August when berries and mast crops start producing. Living in the mountains with lots of snow for much of the year means bears are not eating for much of the year. 6 months in the den is common.
The bear mating season takes place from late May through early July and bears, especially boars, are burning more calories than they are taking in due to high mobility and lack of nutrient dense feed. Generally speaking bears in Idaho have from about mid-July through late September to pack on enough fat to get them through the winter and the negative foraging period in the spring, ie short growing season similar to trout in small, high mountain lakes vs a large, low altitude reservoir. Their heads get big and their bodies stay small.
In areas of the country that regularly produce large bodied bears of 500 pounds plus, there is usually much less time spent in the den and food sources available most of the year that are nutrient dense.
Also for reference, just compare inland grizzlies to coastal brown bears. A good size inland grizzly is 500-600 pounds, whereas coastal brown bears may be 400 pounds heavier. Genetics yes, but mostly environment.
The bear mating season takes place from late May through early July and bears, especially boars, are burning more calories than they are taking in due to high mobility and lack of nutrient dense feed. Generally speaking bears in Idaho have from about mid-July through late September to pack on enough fat to get them through the winter and the negative foraging period in the spring, ie short growing season similar to trout in small, high mountain lakes vs a large, low altitude reservoir. Their heads get big and their bodies stay small.
In areas of the country that regularly produce large bodied bears of 500 pounds plus, there is usually much less time spent in the den and food sources available most of the year that are nutrient dense.
Also for reference, just compare inland grizzlies to coastal brown bears. A good size inland grizzly is 500-600 pounds, whereas coastal brown bears may be 400 pounds heavier. Genetics yes, but mostly environment.