Why do we play winter as a "lean time"?

[Aeron Ganesa]

Also think of migration. With no humans hindering prey are more able to move to area's where there is more food for them. Its cold up north though most animals don't travel far. For packs near the coast or in the lower parts. The herds might move more north to head to a more main land area and even cross over into main Canada. This could also lessen the food supply.

Because I mean most of the studies are done well now. Fences humans and other things throw off and alter Normal Migration. So with out them and human things crumbling it allows more roaming room.