Species richness, abundance and reproductive responses of riparian birds to habitat restoration in the Okanagan Valley

In western North America, most riparian habitats have been destroyed or degraded as a result of human settlement and urban development. I examined temporal trends in the abundance, richness and breeding performance of riparian birds in response to restoration of remnant riparian habitat within the south Okanagan Valley, an arid region of Canada. Total abundance and richness increased over the last decade. Restoration increased the abundance of Yellow-breasted Chats (Icteria virens auricollis), the target of management activities, but did not have a detectable effect on the abundance of other songbirds. The habitat characteristics and breeding performance of Yellow-breasted Chats in restored habitat are currently similar to those of Yellow-breasted Chats in reference sites. Habitat characteristics on multiple spatial-scales (shrub cover of the territory and foliage height of the nest patch) influenced the breeding performance of Yellow-breasted Chats. These results provide evidence that limiting grazing is beneficial to some shrub-nesting songbirds.