RHINELANDER - Winter weather in the Northwoods can be tough on some people. But we don't usually think about how the climate affects the deer population.

D-N-R Wildlife Biologist Jeremy Holtz gets paid to keep track of deer numbers year-around.

Because winter affects the population, The W-S-I scale is his best friend.

“The W-S-I metric or Winter Severity Index is the number one metric in deer management. We write down the minimum temperature of the day and the snow depth of the day. When the snow depth gets to 18-inches or higher, that's a mark; when the temperature gets below zero, that's also a mark.”

So far this season's W-S-I comes in at a mild 20-point. Holtz has been around long enough to see what a bad winter can do.

“In 2007, at this time we were over 100. So you could imagine that deer were starving to death. They were dying of exposure, getting run down by coyotes. There were all sorts of things going on that were limiting the deer population.”

The 2007 winter cut deer totals in a big way. But thanks to a string of mild winters, deer numbers are at a normal level.

Story By: Ryan Abney