Graduation Date
Summer 2026
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Wildlife
Committee Chair Name
Jeffrey Black
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Micaela Szykman Gunther
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Barbara Clucas
Keywords
Affiliative behavior, Allogroom, Groom, Social play, Reciprocity, River otter, Sociality, Symmetry
Subject Categories
Wildlife
Abstract
Patterns of participation in affiliative behaviors may reflect underlying social dynamics. Two affiliative behaviors, allogrooming and social play, were assessed for their symmetry, or relative participation of participants, in a wild group of North American river otters. Behavioral observations were conducted over five months at the Little River estuary in northern California using video recordings and all-occurrence sampling. Observations included all-adult groups, a family group consisting of a breeding female and two pups, and an extended family group with one or two helpers, indicative of cooperative breeding. Individuals engaged in allogrooming and social play were classified by their group membership, age, and social role. Measuring the relative participation of individuals describes symmetry in the exchange, whether the exchange is one-sided or balanced, and this was quantified using indices of grooming symmetry and play symmetry. Generalized linear and generalized linear mixed models were used to evaluate how symmetry varied across social contexts. Overall, allogrooming was highly symmetrical, with higher symmetry observed in all-adult groups and lower symmetry in family groups. Within family groups, adult–pup grooming was significantly less symmetrical than adult–adult grooming. In contrast, social play showed greater variability and overall lower symmetry, particularly among adult-adult dyads, while play between pups was more symmetrical. The breeding female and helper contributed similarly to grooming pups, but helpers engaged in play with pups more frequently. These results indicate that the symmetry of affiliative interactions and division of caregiving behaviors in this system varied across social contexts, particularly by social group, age composition, and social role composition.
Citation Style
Journal of Wildlife Management
Recommended Citation
Norman, Charlotte E., "Symmetry in affiliative interactions of North American river otters (Lontra canadensis) in a Northern California estuary" (2026). Cal Poly Humboldt theses and projects. 2610.
https://digitalcommons.humboldt.edu/etd/2610