A recent study on northern resident orcas off the coast of B.C. took an unexpected turn when Pacific white-sided dolphins made an appearance. Initially seen as a distraction, the dolphins provided valuable insights into the orcas’ hunting behavior. Researchers from Dalhousie University, UBC, the Leibniz Institute, and the Hakai Institute were investigating how orcas locate food, particularly Chinook salmon, and the differences between the northern and southern resident orcas.
Contrary to the belief that dolphins steal fish from orcas, the study revealed a collaborative foraging relationship between the two species. The dolphins actively participated in hunting salmon alongside the orcas, communicating and working together during deep dives. Videos captured by the researchers showed orcas following dolphins underwater and eavesdropping on their echolocation signals to locate prey.
The study’s lead author, Sarah Fortune, emphasized that the dolphins were not merely opportunistic feeders but actively engaged in the hunting process, contributing to the successful capture of salmon. The orcas, in turn, shared their catch with the dolphins, fostering a mutually beneficial partnership where both species benefited from the collaboration.
The research, conducted over two years in the Johnstone Strait and Queen Charlotte Sound, involved tagging orcas to gather underwater footage. The tags provided valuable data on the hunting behaviors of the orcas, offering a unique perspective on their interactions with dolphins. Drone videography also played a crucial role in capturing the dynamic foraging activities between the two marine species.
The study’s findings shed light on the intricate collaboration and connection between orcas and dolphins in their natural habitat. The researchers documented numerous instances of cooperative hunting behaviors, highlighting the sophisticated strategies employed by these marine mammals. The research not only expands our understanding of interspecies interactions but also underscores the importance of studying such relationships in the wild.
Moving forward, the researchers plan to further investigate the preferences of specific orca matrilines for foraging with dolphins and assess the potential impact on their physical well-being. The study underscores the significance of recognizing the valuable contributions of dolphins in the marine ecosystem and challenges conventional perceptions of their role in interactions with larger predators like orcas.