I was told by a game and fish biologist that breeding and litter size depends on the amount of calories that the female is taking in. More food, more calories, more energy for breeding and bigger litters. Hence the reason that I will shoot every coyote I see in a bobcat area. That usually results in more cats in the next couple of seasons.
Bobcats will be found just about anywhere that coyotes will be found. Focus on brushy areas, and rocky areas to find them. I have found that they seem to be a bit more sensitive to volume than coyotes but will come to the same calls. They are just harder to find because of their population numbers.