While monitoring an osprey nest from a dock in the Potomac River, I was surprised at how many folks referred to the birds as bald eagles. I suppose it’s much like the beaver/muskrat confusion. If you’re not used to seeing them, it can be difficult to tell them apart.
Side by side, it’s easy – adult bald eagles are larger than adult osprey and have more white on their heads and tail feathers. Osprey have white on their undersides. Adult bald eagles have yellow legs, while osprey have grey. Here are a few photos to illustrate the difference.