Language attrition arises in sociocultural niches which are less than optimal for the survival of a speech community. Analogously to what happens with species in nature, the risk of extinction and the evolution of their systems are determined by internal and external conditions as well by the extent of their impact over the population. Changes in the vitality and maintenance of the language and transformations of its structural properties are partly a response to broader and more general socio-historical factors. This paper discusses striking differences of the phonological system of contemporary ?uzã? (Otomanguean) with respect to descriptions made at the beginning of the 20th century. A detailed phonetic description of the variation and change of the sound patterns in ?uzã? are explained as a function of a general process of language obsolescence. It is claimed that the same ecological predictors of extinction for natural species account for the decline of the language.