Graduation Date
Spring 2022
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Wildlife
Committee Chair Name
Matthew Johnson
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Daniel Barton
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Barbara Clucas
Subject Categories
Wildlife
Abstract
Attracting natural enemies to farms to reduce pests has long been a part of integrated pest management for insects, but knowledge of the impact of raptors on rodents and other vertebrate pests is comparatively sparse. In this study, I compared rodent prey on winegrape vineyards in Napa California with and without occupied barn owl nest boxes. We collected data before the breeding season, when hunting pressure should be light, and again when adult owls were hunting actively to feed their chicks. I used the open-hole method to quantify an index of gopher activity, and Sherman live traps to estimate the abundance (minimum number alive) of other rodents. I found that gopher activity declined from before to peak hunting pressure on the vineyard with barn owl nest boxes, whereas it slightly increased on the vineyard without nest boxes. Live trapping revealed that the abundance of mice declined from before to during peak hunting pressure, but this decline was not significantly affected by the presence of nest boxes. Results were inconclusive for voles because they were not well-sampled by our live trapping method, even though analysis of owl pellets confirmed they are an important source of prey for barn owls. This is among the first work in the United States to confirm that barn owl nest boxes can reduce the activity of gopher pests in agriculture. Future work should replicate this study after adding nest boxes to the vineyard that lacks them and employ another method to assess vole abundance or activity.
Citation Style
JWM
Recommended Citation
Hansen, Ashley N., "Evaluating the use of barn owl nest boxes for rodent pest control in winegrape vineyards in Napa Valley" (2022). Cal Poly Humboldt theses and projects. 545.
https://digitalcommons.humboldt.edu/etd/545