Many states have specific rules on what roadkill you can claim. One of those states has made it completely illegal to take home animals you find along the road.
It isn't just Michigan that's the worst. Ohio, Indiana, Illinois, and Wisconsin all rank within the Top 6 states with the most trash in their landfills.
One Michigan species of swan is highly territorial, aggressive, and has a documented case of killing a human. Read what species can be hunted with a DNR permit.