Deep-diving beaked whales dive together but forage apart.

Area of Science:

• Marine Biology
• Bioacoustics
• Animal Behavior

Background:

• Social foraging in echolocating animals presents potential benefits like cooperation and risks such as acoustic interference.
• Deep-diving beaked whales exhibit synchronous group dives, likely for predator avoidance, but the foraging implications remain unclear.

Purpose of the Study:

• To investigate the trade-offs of sociality on foraging behavior in Blainville's and Cuvier's beaked whales.
• To determine if social diving synchrony affects foraging efficiency, acoustic interference, or prey competition.

Main Methods:

• Analysis of acoustic data and dive patterns from social groups of Blainville's and Cuvier's beaked whales.
• Quantification of vocalizations and sound detection ranges during foraging dives.

Main Results:

• Beaked whales can acoustically detect group members for at least 91% of their foraging dives.
• Whales coordinate travel direction during foraging but individual vocal activity is independent of group size.
• Foraging performance is unaffected by group size, indicating no significant intra-group competition or acoustic interference.

Conclusions:

• Close diving and vocal synchronization in beaked whale groups primarily serve to reduce predation risk.
• This social synchrony has minimal impact on individual foraging performance, with no evidence of direct eavesdropping benefits or costs.