Harbor Seal (Phoca Vitulina) Social Dynamics: Behavioral Comparisons of Mother-Pup Pairs, Lone Pups, and Lone Adults in the San Juan Islands, Washington During Summer 2025

Abstract

June to September are some of the most vulnerable months for harbor seals (phoca vitulina) in the San Juan Islands because of human disturbances during the pupping season. When threatened, mother seals may flush and abandon their pup until the disturbance is gone. Extended separations from mom can be fatal, and as anthropogenic disturbances increase, the amount of abandoned pups could also increase in the next upcoming years. Our research aims to provide information for harbor seal pup rehabilitation and conservation in the Salish Sea by observing mom-pup pair interactions and important social behaviors they do together. Additionally, our research provides knowledge on social behavior of lone pups and lone adults which can be used for further research to compare habituation of these animals. We found that lone adult seals spent the most amount of time resting/loafing, while lone seal pups spent the most amount of time being vigilant compared to other seal groups. We also found that mom-pup pairs spent 100% of flushing and swimming time together, revealing the importance of mothers showing pups how to flush and the necessity of giving seals the opportunity to swim in rehabilitation centers.