The white-tailed kite (Elanus leucurus) is a small raptor found in South America and parts of western North America. It replaces the related Old World black-winged kite in its native range.
Taxonomy
The white-tailed kite was described in 1818 by French ornithologist Louis Pierre Vieillot under the binomial name Milvus leucurus, with the type locality as Paraguay. It is now one of four species in the genus Elanus, which was introduced in 1809 by French zoologist Jules-César Savigny. The word Elanus is from Ancient Greek elanos for a "kite". The specific epithet leucurus is from the Ancient Greek leukouros for "white-tailed": leukos is "white" and oura is "tail".
For some recent decades, it was lumped with the black-winged kite of Europe and Africa as Elanus caeruleus and was collectively called black-shouldered kite. However, the American Ornithologists' Union accepted a more recent argument that the white-tailed kite differed from the Old World species in size, shape, plumage, and behavior, and that these differences were sufficient to warrant full species status. Thus, the white-tailed kite was returned to its original name. Meanwhile, the Old World E. caeruleus is once again called black-winged kite, while the name black-shouldered kite is now reserved for an Australian species, Elanus axillaris, which had also been lumped into E. caeruleus, but is now regarded as separate again.
Description
The coloration of the white-tailed kite is gull-like, but its shape and flight are falcon-like, with a rounded tail. While it has white faces and white underparts, it has black wingtips, beaks, and shoulders. Contrastingly, the white-tailed kite has deep red eyes that stand out at night. A mid-sized kite, it measures 35–43 cm (14–17 in) in length, spans 88–102 cm (35–40 in) across the wings, and weighs 250–380 g (8.8–13.4 oz). Both the wings and tail are relatively elongated, and the tarsi measure around 3.6 cm (1.4 in).
