LANDSCAPE AND VEGETATION FEATURES IMPROVE RESTORATION SUCCESS FOR BIRDS: USING THE RIPARIAN BIRD INDEX TO EVALUATE CREEK RESTORATION IN CALIFORNIA RANGELANDS

Kathleen E Grady; Sonoma State University; gradyka@sonoma.edu; Derek J Girman, Thomas Gardali

Grazing practices and development at ranches and dairies in coastal northern California have led to a decline in riparian habitat and its associated benefits. However, stakeholders have been restoring riparian vegetation. We examined avian response to riparian restoration on these private lands to measure restoration success. We used avian surveys from 40 plots at 20 sites between 2001 and 2016. Sites ranged in age from 0 to 27 years since revegetation. Surveys were scored using the Riparian Bird Index (RBI), a richness index that gives higher scores for species closely associated with riparian vegetation. RBI scores were found to increase significantly with increasing restoration age. Vegetation data were collected in 2016 to examine the effect of local vegetation on RBI score. Canopy cover and non-willow canopy were found to be significant predictors of RBI score. We analyzed sites at the landscape scale to understand what plot size and location variables best predict bird response. We found that corridor width and size and proximity of the nearest protected area were significant. Our study shows that riparian restoration in this study area has been successful for birds. We suggest that continued long-term monitoring is crucial to understanding restoration success and to managing sites.

Ecology and Conservation of Birds II     Student Paper