Group Dynamics and Social Structure of the Inia araguaiaensis in the Tocantins River, Brazilian Cerrado

Knowing the ecological aspects and social dynamics of a natural population is important to assess how animals respond to the impacts of human activities in their habitats, which aids in the identification of conservation strategies. The Inia araguaiaensis, locally known as the Araguaian boto, is a poorly known species, categorized as vulnerable to extinction. It has a restricted geographical distribution in the Tocantins-Araguaia river basin, impacted by various anthropogenic activities, including the construction of seven hydroelectric dams along the Tocantins River. The social dynamics of the Araguaian botos were investigated using data from 35 individually identified animals between the years 2013 and 2019. The animals showed a fission–fusion social structure, forming occasional associations for different activities, especially feeding and socializing. The lack of systematic research before the Power Plant construction hampers our ability to fully understand the impact of the hydroelectric dam on this population. Although the damming of the river has temporarily increased prey concentration, it has also brought negative consequences due to changes in water flow and population fragmentation, affecting species conservation. Therefore, it is crucial to conduct continuous and long-term monitoring of the Araguaian boto population, which is one of the least studied species in its taxonomic group.