"The wolf breeding season is coming up in the next few weeks here in northern Minnesota. You start to see more scent marking as we get closer to breeding season. You might see estrus blood from the dominant female as she and the dominant male scent-mark territorial pack boundaries. You might even hear more howling and evidence of defense of territory. Wolves only breed once per year, with peak activity in about early February. As you go farther north into the Arctic, that peak goes later into March. And the gestation period is 64 days. So we usually see pups here in Minnesota around the last week of April."

Lori Schmidt, wolf curator, International Wolf Center in Ely, Minn.

More information about wolves and winter wolf events: www.wolf.org.