Of course, not all of the 742 square miles in unit 77A is deer habitat, or what the DNR calls deer range. Much of it is cities, farm fields and parking lots. In unit 77A, the DNR estimates that only 24 percent, or 178 square miles, is deer range. So, if unit 77A had 3,817 deer after the 1999 hunting season living on 178 square miles of deer range, 21.4 deer roamed each square mile of deer range. That was slightly over goal, which for unit 77A is 20 deer per square mile of deer range.
Different units have different goals, which are reviewed every three years.
The goals are based on different criteria. In northern forest units, the amount of winter food available for deer is a primary concern. Too many deer, too little food and a harsh winter can add up to a huge winter kill. In southern units, however, food is abundant and winters are easier. Winter kill poses little threat.