Lauren M. Jackson Thesis Defense | Cal Poly Humboldt

Evidence of personality and movement syndromes in a mobile predator: How individual hunting strategy shapes ecosystem service potential by barn owls (Tyto furcata) in an agroecosystem 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. These findings suggest that predator-mediated ecosystem service potential depends partly on repeatable individual differences in movement behavior.