Impacts of passive relocation on the survival, dispersal, and reproduction of Burrowing Owls (Athene cunicularia) in southcentral Arizona
| Authors: | Savannah Finch, Fitsum Abadi, David H. Johnson, Adam Duarte, Martha J. Desmond |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Pacific Northwest Research Station |
| DOI: | https://doi.org/10.3356/jrr2585 |
| Source: | Journal of Raptor Research |
Abstract
Land development in the southwestern USA has caused intensive landscape change and created conflicts with Burrowing Owls (Athene cunicularia), which rely on underground burrows and occupy sites often attractive for development. Passive relocation is a mitigation method for owls on development sites that involves excluding owls from their burrows followed by collapsing and filling those burrows to prevent reuse. We worked with developers in Phoenix, Arizona, to locate owls, and we evaluated how passive relocation and other factors influenced their survival, dispersal, and reproduction. From 2021 to 2022, we used radiotelemetry to monitor 25 resident (control) owls and 14 passively relocated owls. Known-fate models indicated higher annual survival for control owls (0.65, 85% confidence interval [CI] = 0.44, 0.87) than for passively relocated owls (0.43, 85% CI = 0.16, 0.70); however, 85% CIs for all regression coefficients bounded zero, suggesting insufficient evidence to confirm the potential effects of evaluated factors. Displaced owls dispersed farther than control owls (x̄ = 450.73 m vs. 121.21 m), though most owls remained within their home ranges. For every one SD increase in the percentage of agriculture within 200 m of a nest, the odds of owl nest success increased by a factor of 2.51 (85% CI = 1.04, 6.01) and expected productivity increased by a factor of 1.62 (85% CI = 1.04, 2.51). The effectiveness of passive relocation relied on the availability of habitat and burrows within owl home ranges and communication with developers. Limitations related to coordination with developers, project scales, and burrow availability before displacement necessitate further investigation.