A MODEL TO EVALUATE BARRED OWL (STRIX VARIA) REMOVAL STRATEGIES FOR NORTHERN SPOTTED OWL (STRIX OCCIDENTALIS CAURINA) CONSERVATION.

Ryan C Baumbusch; Humboldt State University; ryan.baumbusch@humboldt.edu; Lowell, V., Diller, Daniel, C., Barton

In ecosystems throughout the world, lethal removal of one species is sometimes seen as necessary for the conservation of another. Modeling alternative removal strategies can inform decision-making so that resources are not directed towards ineffective or inefficient actions and, perhaps more importantly, to avoid culling animals using strategies with little to no conservation benefit for the species of concern. Lethal removal of barred owls has been proposed as a management option for the conservation of northern spotted owls. We developed an individual-based spatially explicit population model to compare the efficacy and efficiency of alternative barred owl removal strategies. The model evaluates how well an area can be maintained free of barred owls as well as the impact a strategy might have on the broader population of barred owls beyond the removal area. We compared several basic approaches for implementation of removal across space and time within a homogenous habitat. We also identified parameters of interest where further empirical field research could refine model predictions. The flexible nature of the model allows further development to answer more complex questions concerning barred owl removal as well as application to property-specific evaluation when landowners or managers propose or consider barred owl removals.

Challenges and Conflict in Vertebrate Predator Management     Student Paper