I'll add this, one of the best ways to get and keep good traping locations is to manage the animals as if the place was yours. This applies to depredation as well as balance and fur quality. I trap way into March, by then concentrating on a few more Toms. I always work the coyotes hard in and around the calving pastures by this time 1 of 10 maybe worth skining. By taking care of the coyotes my ranchers smile when they see me come and work with me...this counts for a lot.
This is a differnet sort of answer to your original question.