Чакская чачалака Ortalis canicollis

Large noisy bird with a long tail. Rather uniform brown plumage with little contrast between its head and the rest of the body. Inhabits swampy forest, savanna, and second growth, where found in groups which may exceed 30 individuals. Feeds on fruits and seeds on the ground or in trees. Gives a typical loud chachalaca song, a rollicking duet “bink, ka chee chaw raw taw, chaw raw taw, chaw raw taw.” Calls include a low “cha-cha-cha.”