Red-bellied

Like the red-headed woodpecker, this one likes collecting acorns. Look for a slight red patch on their bellies, a red nape or nape and crown, and barred wings.
Pileated

The largest one in this family, these woodpeckers sport a red-peaked head and a black body that can be more than a foot long.
Black-backed

With black feathers and a streak of golden yellow on its head, this northern Minnesota woodpecker has barred feathers on its sides and three toes.
Downy

The tiniest in the family, this little woodpecker has a small bill and streak of red on its head.