Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME I.
GENUS XI.--CIRCUS, Bechst. HARRIER.
Bill short, compressed; upper mandible with the dorsal line sloping to
beyond the cere, then decurved, the sides sloping, the edge with a festoon a
little anterior to the nostril, the tip acute; lower mandible with the dorsal
line ascending and convex, the tip rounded. Nostrils large, ovato-oblong, with
an oblique ridge from their upper edge. Head of moderate size, oblong, neck
rather short; body slender. Legs long and slender; tarsi long, compressed,
anteriorly and posteriorly scutellate; toes slender, scutellate unless at the
base; claws long, compressed, moderately curved, flat beneath, acuminate.
Plumage very soft; a distinct ruff of narrow feathers from behind the eye on
each side to the chin, the aperture of the ear being very large. Wings long,
much rounded, the fourth quill lonest; outer four quills with their inner webs
sinuate. Tail straight, long, slightly rounded. Quills and tail feathers
covered with velvety down.