Mountain lions have a problem in the winter. Normally, they need
to get several meals from a killed animal in order to survive.
In the warmer months this is no problem. In extremely cold winter
months the jaws of the cougar are not strong enough to chew meat
that has frozen. A wolf, however can crush bones in its teeth
and has no problem with wild "frozen food entrees".
Harsh winters can diminish the cougar populations but fortunately
for wildcats winters are moderating significantly in Western Canada.