You notice that some squirrels in your neighborhood have a much darker coat color than most of the other squirrels. Is this darker color an adaptation

Yes, it is an adaptation.

Explanation:

The squirrels with the darker coat color may have adapted to fit in with the surroundings, like if your neighborhood had darker colored tree bark. There is also the possibility that they adapted to avoid predators, such as stray cats and dogs (which would mean that they adapted to become less visible to their attacker).

when it is at an intermediate population density

yes we can.   a lady urinates from her urethra.