| The availability of water is arguably the most important landscape factor, particularly in arid climates. Homeowner decisions regarding irrigation are likely to have a direct effect on bird species richness. Previous research has suggested a link between socioeconomics and urban species diversity. This empirical study examines a potential pathway for this relationship: Neighborhood socioeconomic status influences residential irrigation intensity, which influences plant cover, in turn influencing bird diversity. This study uses results from the Fresno Bird Count, a citizen science project, along with socioeconomic, vegetative, and irrigation data. Both bird species richness and foraging guild richness were examined. Irrigation intensity decreases in areas with greater poverty levels (P<0.0283). A multivariate model links avian species richness with poverty levels, irrigation intensity, and amount of vegetation (Whole model R2=0.682, P<0.0008). Guild richness decreases in areas of greater poverty levels (R2=0.216, P<0.0042) and less intense irrigation (R2=0.131, P<0.0303). In a multivariate model irrigation intensity, vegetative factors and poverty levels are strong predictors of guild richness (Whole model R2=0.521, P<0.0009). In arid urban areas, irrigation is a key driver of bird communities. Many communities like Fresno, CA are undergoing changes in water policies that are likely to change residents' irrigation behavior. Thus, understanding water management is critical for a deeper theoretical understanding of urban ecosystems and for effective urban policy. |
