The Snail Kite (Rostrhamus sociabilis) is a bird of prey within the family Accipitridae, which also includes the eagles, hawks, and Old World vultures. Its relative, the Slender-billed Kite, is now again placed in Helicolestes, making the genus Rostrhamus monotypic. Usually placed in the milvine kites, the validity of that group is under investigation.
Snail Kites are 36 to 48 cm (14 to 19 in) long with a 99–120 cm (39–47 in) wingspan. They weigh from 300 to 570 grams (11 to 20 oz).There is very limited sexual dimorphism, with the female averaging only 3% larger than the male. They have long, broad, and rounded wings, which measure 29–33 cm (11–13 in) each. Its tail is long, at 16–21 cm (6.3–8.3 in), with a white rump and undertail coverts. The dark, deeply hooked beak, measuring 2.9–4 cm (1.1–1.6 in) is an adaptation to its diet. The tarsus is relatively long as well, measuring 3.6–5.7 cm (1.4–2.2 in)