ESTUDO BIOACÚSTICO DE DENDROPSOPHUS NANUS (BOULENGER, 1889) (AMPHIBIA, ANURA, HYLIDAE): UMA ESPÉCIE AMPLAMENTE DISTRIBUÍDA NA AMÉRICA DO SUL

Abstract

The genus Dendropsophus is currently composed of 110 species, organized into nine groups based on morphological similarities and, mainly, on molecular data. The species D. nanus, allocated in the D. microcephalus group, has a wide distribution in South America, occurring in Brazil, Argentina, Bolivia, French Guiana, Paraguay, and Suriname. The advertisement call among anurans is used for specific recognition between individuals, as well as to inform the occupation of that space by males of the same or other species. However, widely distributed species tend to show differences in acoustic parameters when considering their entire distribution area, due to the existence of physical barriers and even latitudinal and longitudinal gradients. Vocalization can drive the anuran speciation process, once it represents a prezygotic reproductive isolation factor and it is under the effect of several selective pressures. Thus, given that widely distributed species have several biogeographic elements that could lead to acoustic variation along their distribution, in this study, we evaluated the advertisement call of D. nanus covering its area of occurrence in South America. We analyzed 103 recordings of the advertisement call of 101 males from 26 locations. We observed a great variation between populations in the acoustic parameters that increases with geographic distance. However, we did not observe any geographic clustering based on acoustic data or a spatial pattern of similarity between populations of this species. Geographic distance influenced the variation on acoustic parameters, however, it was not related to geographic clades formed by acoustic similarities. In addition, it is possible that local factors are acting in the definition of the acoustic patterns found in this study.