In the Pacific of Guatemala, two subspecies of Stenella longirostris can be observed: S. longirostris orientalis (a more oceanic form) and S. longirostris centroamericana (a coastal subspecies), which can be seen during nature-based tourism. The latter is endemic to the Isthmus of Tehuantepec and Central America (Ortiz-Wolford, 2024). In Guatemala, the San José Canyon serves as a key refuge for cetaceans and other large marine fauna.
Video by WCS Guatemala
In terms of feeding behavior, spinner dolphins feed at night on small fish, shrimp, and squid found between 200 and 300 meters below the water’s surface. Their prey follow a vertical and horizontal migration pattern: they remain in deeper waters during the day, where they are less likely to be hunted, and move upward in the water column (vertical migration) and closer to the coast (horizontal migration) at night when light levels are lower. Spinner dolphins take advantage of this nightly migration, which brings prey into shallower and nearshore waters, allowing them to feed throughout the night.
This species lives in large groups and is rarely seen alone. They show strong social dependence, usually staying in pairs or larger pods. This behavior is linked to their feeding strategy, as hunting in groups allows them to better encircle and trap their prey (Lammers & Au, 2003).
These groups produce complex whistles—narrow-band, frequency-modulated tonal sounds—that play a crucial role in communication within and between groups. In some dolphin species, these whistles may serve as individual identifiers, making them essential in social contexts.
A dolphin’s characteristic whistle is a distinctive acoustic signal with unique frequency modulation patterns. It enables individuals within a group to recognize one another, helping maintain contact and group cohesion (Río, 2023). These modulated-frequency vocalizations remain stable throughout a dolphin’s life and develop during the first months through vocal learning based on social and auditory experiences.
This information comes from marine fauna monitoring conducted in collaboration with Semillas del Océano and the Center for Marine Studies and Aquaculture (CEMA-USAC).
Text by José Moreira (WCS Guatemala)