Whale See, Whale Do: Drone Observations Reveal Social Learning Processes in Mom-Calf Pairs.

Abstract

Social learning is a key indicator of culture and a valuable process to understand due to effects on behavioral diversity and specialization with subsequent impacts on population survival. While social learning has been identified and quantified across a diverse array of taxa, the specific underlying processes are rarely identified. However, identifying the mimetic process involved in learning is important as it informs our understanding of a species' cognitive abilities and contributes to the study of cultural and cognitive evolution. Social learning and culture are often studied in cetaceans, particularly amongst odontocetes, but processes have only been identified in human care. Here, we analyze opportunistic drone footage of Pacific Coast Feeding Group (PCFG) gray whale mom-calf pairs foraging off the coast of Oregon, USA for evidence of foraging tactic mimicry and evaluate alignment with different mimetic processes. We filmed 15 pairs across 9 years and observed a calf performing a foraging tactic while its mom was foraging in 6 of the pairs. The calf always initiated the tactic once its mom was already performing her tactic and the calf's tactic was either the same as its mom's current or previously performed tactic within the observation period. Furthermore, we present observations of these calves in later years employing tactics they observed their moms perform. We conclude that the process of stimulus/local enhancement occurs in most of our observations and find evidence suggesting imitation in calves attempting to reproduce an opaque movement (i.e., movement with dissimilar sensory inputs when observed and executed) performed by its mom. These findings represent the first evidence of social learning and vertical transmission of foraging tactics in gray whales, suggesting that gray whales are capable of complex cognitive tasks and that foraging tactics may be part of PCFG gray whale culture.