Why does a baby eagle have such long, fluffy feathers on its head? The head loses body heat more quickly than other parts of the body, so the fluffy feathers provide important insulation. These long white feathers grew in very quickly after the baby eagle hatched. They will be pushed out as mature feathers grow in.

Notice how thick the down feathers are. They look more like fur than feathers. As the outer feathers grow in, this down will be covered up by contour feathers — the ones that will give it that distinctive eagle appearance. It will take 3 or 4 years for this bald eagle to grow white feathers on its head and tail.

Peter Nye