The ecological role of native‐plant landscaping in residential yards to birds during the nonbreeding period

Abstract

AbstractResidential yards are a form of urban land use that cover a considerable amount of area in cities worldwide and provide important habitat for wildlife, especially when landscaped with native plants. Nevertheless, most native‐plant landscaping and wildlife research in the northern temperate regions of the world has been conducted during the spring and summer breeding period, leaving a gap in our understanding of the importance of residential yards and native plants as habitats for animals during the nonbreeding period. To fill this gap, we quantified the ecological role of native‐landscaped yards to avifauna throughout Greater Los Angeles (LA), California, during the winter nonbreeding period, which is a time of year when the region hosts a high abundance and diversity of migratory and resident birds. We surveyed birds and habitat features from October to March of 2020 and 2021 at 22 pairs of native‐ and non‐native‐landscaped yards plus 10 additional native‐landscaped yards. We had three objectives for our study. First, we compared avifaunal communities, including feeding and nonfeeding behaviors, and habitat features between native and non‐native‐landscaped yards. Second, we quantified relationships between habitat features and bird richness, abundance, and feeding and nonfeeding behaviors—focusing on species affiliated with urban or natural terrestrial ecosystems of the region. Third, we documented feeding and nonfeeding behaviors by birds with native and non‐native plants. Native‐landscaped yards had a greater cover of native trees, shrubs, and herbaceous plants, and a higher cover of natural habitat elements, including leaf litter and bare‐ground cover. Bird richness and abundance—especially bird species affiliated with tree‐ and shrub‐dominated ecosystems—were greater in native than non‐native‐landscaped yards. Further, yards with a higher cover of native plants supported greater numbers of feeding birds, with individuals focusing their foraging behaviors on distinct native trees and shrubs, including Quercus spp. (oak), Heteromeles spp. (toyon), Arctostaphylos spp. (manzanita), and Salvia spp. (sage). Our results suggest that residential yards landscaped with native plants provide important habitat for birds during the nonbreeding period and are a viable approach for residents and cities if improving conditions for birds throughout the annual cycle is a goal.