 However, the exact distribution limits of some of the subspecies are unclear.Notably the population between the Madeira and Purús Rivers (between generally reported range of "C. u. adspersus" and "C. u. yapura"), and the population between the Tapajós and Araguaia Rivers (between generally reported range of "C. u. adspersus" and "C. u. vermiculatus") appear not to have been assigned to subspecies.The undulated tinamou is approximately in length, and weighs around .