Although I’d consider a number of species to be more spherical than White-breasted Nuthatches (Horned Larks, kinglets, and many warblers), few have such an optimistic stance.
Photo by Kelly Colgan Azar
Bouncing and scuttling up tree trunks, the Red-breasted Nuthatch might closely resemble the related White-breasted Nuthatch, but the Red-breasted is much smaller and contains its namesake red breast along with a bold black eyeline which the White-breasted lacks.
Photo by Andy Reago & Chrissy McClarren