Graduation Date

Summer 2026

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Wildlife

Committee Chair Name

Matthew Johnson

Committee Chair Affiliation

Cal Poly Humboldt Faculty or Staff

Second Committee Member Name

Barbara Clucas

Second Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Third Committee Member Name

Tim Bean

Third Committee Member Affiliation

Community Member or Outside Professional

Keywords

Barn owls, Ecosystem services, Personality, Movement syndromes, California, Pest control, Vineyards, Behavior, Movement, Plumage, Individual, Agroecosystems, Raptors, Mobile predators

Subject Categories

Wildlife

Abstract

Animal-mediated ecosystem services are delivered through the behavior of individuals, yet most studies evaluate service-providing species at the population level. We tested whether individual variation in plumage, behavior, and movement predicted hunting behavior and vineyard habitat use by adult male American barn owls (Tyto furcata) nesting in winegrape vineyards in Lodi, California, USA. We fitted GPS-accelerometer tags to 42 breeding males, quantified breast-plumage traits, measured neophobia using repeated novel object tests, and derived nightly movement metrics from GPS tracks and hidden Markov model-classified hunting locations. Several behavioral traits were repeatable, but movement traits showed the clearest repeatable individual variation. Six repeatable movement traits – hunting habitat diversity, ranging extent, hunting-bout duration, hunting-site revisitation, path tortuosity, and hunting core area – were summarized into two movement syndromes: space-use strategy, describing ranging extent and site revisitation, and hunting search strategy, describing hunting habitat diversity, bout duration, and tortuosity. Plumage and behavioral traits did not clearly predict movement syndromes, suggesting little support for a plumage-linked or broad bold-shy behavioral syndrome. In contrast, movement syndromes predicted vineyard hunting use and vineyard selection. Owls with more directed, persistent hunting strategies used and selected vineyard habitat more strongly. Vineyard availability near the nest was also positively associated with vineyard use and selection, while neophobia received some support as a predictor of vineyard use, with less neophobic owls using vineyard landcover during hunting more often. These findings suggest that predator-mediated ecosystem service potential depends partly on repeatable individual differences in movement behavior.

Citation Style

Elsevier Harvard

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