Scarlet Tanager, Piranga olivacea
The bright red body and black wings of the breeding-plumage male Scarlet Tanager make it one of the most spectacular of North American songbirds. It tends to frustrate would-be photographers by mostly staying high in the forest canopy; this one gave me a chance by descending lower than others we saw during our four days photographing in southern Ohio's Shawnee State Forest during April 2015.
The bird may seem to be carrying vegetation in its mouth, but males of this species don't participate in nest-building, and are insectivores; on closer inspection, an insect leg is visible below the birds lower mandible. The insects most famous for looking like leaves are the katydids, and I suspect that this is one.