2. Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern Brazil

Considering long-term study as one that through constant efforts subsidizes future studies, an example in Brazil is “Projeto Boto-Cinza” adding up more than 36 continued years of research and data application on Guiana dolphin biology, ecology and conservation. The first effort we dedicated was toward understand the fishing strategies used by this species, lasting about 10 years. Latter, as we gained knowledge in behavior study, the next step was to access parental care, youngling behavior, learning process of fishing, acoustic repertoire, and recently social networks. Throughout this time, it was possible to access also the mortality, and based on carcasses that gave such information, access parameters of life history such as reproductive anatomy of males and females, pregnancy period, birth size, and even age. Population density estimates could be done in different periods and areas; photo-identification enabled the detection of individual spatial fidelity. Modeling permitted to observe which parameters seem to be associated with the spatial distribution of population units inside the estuary. All these data contributed to a greater knowledge about the species, creation of public policies by conservation units’ chiefs, education purposes, and conservation of the species.