Side view of the Barn Swallow's claw. "Hirundo horreorum. Barn Swallow. Tarsi shorter than middle toe and claw, above feathered for a little distance; basal joint of middle toe partly adherent to both lateral toes." Elliot Coues, 1884

Barn Swallow Claw

Side view of the Barn Swallow's claw. "Hirundo horreorum. Barn Swallow. Tarsi shorter than middle toe…