We used radio-telemetry to record how Caiman yacare (Cy) and Melanosuchus niger (Mn) responded to the intrusion of the Maniqui river into Cedral Lagoon in the Bolivian Amazon. Nine M. niger and 3 C. yacare were followed between December 2015 and May 2016. Both species showed a gradual reduction in mean monthly range from December (19.96 ha Mn and 1.74 ha Cy) to May 2016 (0.08 ha Mn and 0.24 ha Cy). Habitat use was fairly constant throughout the months for both species, Melanosuchus niger used mainly open swampy forests and Cyperaceae Marshes, while C. yacare used more islands and flooded grasslands. This study shows that both species of caimans responded to changes in depth and vegetation types, as their habitat as a whole was changed by river intrusion.

Understanding of snake ecology has increased over the past two decades, but is still limited for many species. This is particularly true for the recently described Beni anaconda (Eunectes beniensis). We present the results of a radio-telemetry study of nine (3M:6F) adult E. beniensis, including home range, and habitat use. We located the snakes 242 times in wet season, and 255 in dry season. Mean wet season home range (MCP) was 25.81 ha (6.7 to 39.4 ha); while mean dry season home range was 0.29 ha (0.13 to 0.42 ha). We found no relationship between home range size and either snout-vent length, weight, or sex. Beni anacondas seem to prefer swamps, and patujusal, while avoiding forest, and rice fields. However, habitat use by individual snakes seems to vary based on the habitats available within their respective home range. Notably, rice fields were avoided by most snakes, which suggests that this type of habitat is unsuitable for anaconda management.

Identifying patterns of herpetofaunal diversity is imperative to the conservation of these species and the ecosystems on which they rely. In this study, we determined species occurrence and composition of the herpetofauna at the Reserva de Biósfera Estación Biológica del Beni and the Chimane Reserve Indigenous Territory. Combined data resulted in documentation of 97 species belonging to 22 families and 50 genera. Reptiles were represented by 14 families and 47 species, while amphibians were represented by eight families and 50 species. This study provides a robust inventory and report of the herpetofauna at this site and delivers data that can be used in future studies. Our results indicate that this site harbors many species, which likely contributes to the collective maintenance of biodiversity in the Bolivian lowlands. Conservation initiatives should consider the collective uniqueness of vertebrate communities maintained by habitat mosaics in this area and strive to implement strategies that preserve and manage landscape-level biodiversity.

La vulnerabilidad de las serpientes al cambio climático, la pérdida de hábitats naturales y el conflicto con los humanos hacen imperiosa la necesidad de conocer más sobre su diversidad en el territorio boliviano. Además, debido al temor que las personas les tienen a las serpientes, muchas de ellas son eliminadas intencionalmente y muchas otras mueren atropelladas en las carreteras, por lo que estos ejemplares son una fuente importante para el registro de especies. Esta información fue obtenida en los alrededores de la ciudad de San Borja en Beni- Bolivia y se comparó la cantidad y la riqueza de especies registradas con estudios de extrapolación y registros previos. En total se recolectaron e identificaron 82 individuos, de 43 especies, pertenecientes a cinco familias. Por las comparaciones con otros estudios, podemos estar seguros que en esta región hay 54 especies de serpientes confirmadas. Este estudio no sólo aporta al conocimiento de la diversidad de serpientes del suroeste del departamento del Beni, sino que, además, resalta la importancia de las colectas provenientes del conflicto humano-serpiente.

Figure 1. A dicephalic False Coral Snake (Oxyrhopus emberti): dorsal and ventral views of the snake (A-B), dorsal and ventral views of the heads (C-D), and heads joined laterally at the angle of the jaws (E). Photographs by Paola De la Quintana.