Home range and habitat use of two sympatric crocodylians (Melanosuchus niger and Caiman yacare) under changing habitat conditions

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.