If Minnesota is having a very cold winter with deep, drifting snow the the wolves will dine well on moose. On crusted wind-blown snow a wolf can glide over the snow while the moose has to plow through it. Wolves always dine best in winter.
So far, they said, a fifth of the adults have died with predators, infections, parasites, or injuries listed as causes. And 74 percent of the calves died, a number that surprised researchers. The greatest number of calf deaths were attributed to wolves and bears. But another 11 died as a result of being collared: Nine were abandoned by their mothers, one died after the mother stepped on it during the collaring attempt, and the 11th died for unknown reasons.
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