Parental care behavior in the Guiana dolphin, Sotalia guianensis (Cetacea, Delphinidae), in southeastern Brazil

Parental care is any form of parental behavior that increases offspring fitness. This is the first study, to the authors’ knowledge, that analyzes the intensity of parental care for the Guiana dolphin (Sotalia guianensis). The objectives of this study are; 1) to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro, 2) to investigate the effect of behavioral state and group size, on the degree of parental care and 3) to evaluate differences in the intensity of parental care between calves and juveniles. Our results indicate that parental care is intensely performed in S. guianensis and in group sizes with higher mean values care is more intense, possibly as a way of maximizing hydrodynamic gains and to minimizing risks. Results suggest parental care is more intense during travelling, possibly because feeding dynamics are more random than other behavioral states. Moreover, results indicate that calves receive a higher intensity of care than juveniles, suggesting a possible parent-offspring conflict.