NEST SITE SELECTION OF FERRUGINOUS HAWK WITHIN BUTTE VALLEY

Sierra G Olsen; Cal Poly Humboldt; sgo10@humboldt.edu; Elizabeth Meisman, Matthew Johnson, Dr. Chris R. Vennum

The ferruginous hawk (Buteo regalis) is the largest Buteo species in North America, and occupies arid grasslands. A small population of ferruginous hawks has been observed breeding within Butte Valley, California located in the northeastern region of the state. We investigated nest site selection at the nest tree scale via collection of on-the-ground nest tree attributes and on a larger habitat scale via resource selection functions utilizing land cover types. We compared nest tree height and diameter at breast height (DBH) to the four nearest neighbor trees based on surveys conducted during the 2024 breeding season. Using matched case logistic regression, we found that ferruginous hawks show a slight positive selection for tree height and DBH. Using monitored nest site locations, we conduct analysis on different natural and agricultural land cover types and report patterns distinguishing occupied nests and random points through generalized linear models . This research may aid in understanding breeding habitat requirements and can assist managers in predicting new nesting sites as this population continues to grow.

Poster Session   Student Paper