Additional Funding Sources
This research, conducted at the Raptor Research Experiences for Undergraduates site, was supported by the National Science Foundation and Department of Defense under Grant No. DBI-1852133 and by Boise State University.
Presentation Date
7-2021
Abstract
As an apex predator and an indicator species, Northern Goshawks play a crucial role in the ecosystem of the Sawtooth National Forest and they are considered important to the Forest Service in matters of forest management. In recent years we’ve observed declining breeding rates, nest success, and productivity within the region. We are interested in better determining the contribution of prey abundance to these trends. To this end, we will record observations of common Northern Goshawk prey species seen and heard along 750 m transects from the most recent or currently occupied nest. We will perform distance sampling analysis to generate prey abundance estimates for each territory. We will use those estimates as predictors in logistic regression to predict the response of nest success and occupancy.
We expect that lesser prey abundance will correlate with reduced breeding rate, nest success, and productivity and be consistent with Miller et al. (2014) which showed avian abundance, but not mammalian abundance, to be a predictor of occupancy. We hope to expand upon these finding to determine how goshawks have adapted to prey variety and quantity and the impacts of these changes. Additionally, the results of this study will help to inform future forest management practices that could have an effect on prey abundance for the birds located in these historically inhabited goshawk territories.
Does Prey Composition Influence the Breeding Rate, Nest Success, and Productivity of the Northern Goshawk
As an apex predator and an indicator species, Northern Goshawks play a crucial role in the ecosystem of the Sawtooth National Forest and they are considered important to the Forest Service in matters of forest management. In recent years we’ve observed declining breeding rates, nest success, and productivity within the region. We are interested in better determining the contribution of prey abundance to these trends. To this end, we will record observations of common Northern Goshawk prey species seen and heard along 750 m transects from the most recent or currently occupied nest. We will perform distance sampling analysis to generate prey abundance estimates for each territory. We will use those estimates as predictors in logistic regression to predict the response of nest success and occupancy.
We expect that lesser prey abundance will correlate with reduced breeding rate, nest success, and productivity and be consistent with Miller et al. (2014) which showed avian abundance, but not mammalian abundance, to be a predictor of occupancy. We hope to expand upon these finding to determine how goshawks have adapted to prey variety and quantity and the impacts of these changes. Additionally, the results of this study will help to inform future forest management practices that could have an effect on prey abundance for the birds located in these historically inhabited goshawk territories.