DougMD is correct, most people don' t realize March is the toughest month for deer. Some feel that as the snows begin to melt, and temps rise the deer are safe. When actually its the hardest on them. Like Doug wrote deer have used up their fat reserves, while also having used up their food sources. On top of the increased temps, it causes them to use more energy to get around with those heavy coats. So in some states you won' t get a good idea of winter mortality until April to May.