Whistle variation is associated with surface behavior in the Guyana dolphin (Sotalia guanensis).

Abstract

Guyana dolphins emit whistles with the widest frequency range ever reported today (1.34 to 48.4 kHz). Distance between populations has been suggested as an important factor promoting whistle variation in this dolphin species. However, other factors known to promote intra‐specific whistle variation among delphinids such as behavior have not been explored yet in Guyana dolphins. Behavior has been shown as important factor promoting whistle variation in many whistling species, and thus it should be taken into consideration in comparative studies of dolphin communication. Here, I study the relationship between whistle structure and surface behavioral states (travel, foraging, and social behaviors) of Guyana dolphins from a small resident population in Costa Rica. Behavior had a significant effect on whistle duration and whistle minimum, delta, ending, and start frequencies variables. Moreover, more than 47% of the whistles were correctly classified to their corresponding surface behavior. These results indicate that not only behavior is an important factor contributing to intra‐specific whistle variation in Guyana dolphins but that behavior is an important variable to describe any acoustic study which goal is to compare populations.