Here's why:
* Population Fluctuates: Bear populations change constantly due to factors like food availability, habitat, and hunting regulations.
* Difficult to Count: It's very difficult to count all the bears in such a vast area. Researchers use various methods like tracking, scat analysis, and aerial surveys, but these are estimates.
* Varying by Region: The number of black bears varies greatly from state to state and province to province.
However, estimates suggest there are between 600,000 and 900,000 black bears in North America. This number is constantly changing, so it's best to consult recent studies for more accurate information.