Limpkin

The limpkin is a somewhat large bird, 64–73 cm (25–29 in) long, with a wingspan of 101–107 cm (40–42 in). Body mass ranges from 900 to 1,300 g (2.0 to 2.9 lb), averaging 1,080 g (2.38 lb).[9] The males are slightly larger than the females in size, but there is no difference in plumage.[4] Its plumage is drab—dark brown with an olive luster above. The feathers of the head, neck, wing coverts, and much of the back and underparts (except the rear) are marked with white, making the body look streaked and the head and neck light gray. It has long, dark-gray legs and a long neck. Its bill is long, heavy, and downcurved, yellowish bill with a darker tip.[10][11] The bill is slightly open near but not at the end to give it a tweezers-like action in removing snails from their shells, and in many individuals the tip curves slightly to the right, like the apple snails' shells.[12] The white markings are slightly less conspicuous in first-year birds.[11] Its wings are broad and rounded and its tail is short.[13] It is often confused with the immature American White Ibis.
This bird is easier to hear than see. Its common vocalization is a loud wild wail or scream[10][13] with some rattling quality, represented as "kwEEEeeer or klAAAar."[11] This call is most often given at night[13] and at dawn and dusk.[10] It has been used for jungle sound effects in Tarzan films[14] and for the hippogriff in the film Harry Potter and the Prisoner of Azkaban.[15] Other calls include "wooden clicking",[11] clucks,[13] and in alarm, a "piercing bihk, bihk..."

http://en.wikipedia.org/wiki/Limpkin