There is a difference between a juvenile and an adult bald eagle. Adult Bald Eagles have white heads and tails with dark brown bodies and wings. Their legs and bills are bright yellow. Immature birds have mostly dark heads and tails; their brown wings and bodies are mottled with white in varying amounts. Young birds attain adult plumage in about five years. Shown here are a 1st year and 4th year. A 1st year bald eagle has no white and a dark beak. The fourth year bald eagle is large and heavy-bodied. Similar to adult but with some dark smudging on white head. Heavy yellow bill.