Urban Bird Diversity as an Indicator of Social Diversity and Economic Inequality in Vancouver, British Columbia
Department of Zoology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
The unequal distribution of wealth in cities contributes to other forms of spatial, social, and biological inequities in complex, interacting, and self-reinforcing ways. Recent work on urban birds has often focused on community-level correlation studies of short duration in which many points along an urban gradient are surveyed for birds, and the data are related to various ecological variables measured at multiple scales. Spatial variation in urban bird communities may also reflect socioeconomic variables and cultural differences among the human population. The purpose of this paper was to examine whether socioeconomic factors (such as mean family income and ethnic diversity) also relate to the diversity and abundance of birds in Vancouver, British Columbia. I used redundancy analysis to characterize the socioeconomic gradient in a citywide study of the bird community in 44 census-defined neighborhoods. Mean family income, census-tract area, and ethnicity were some of the dominant variables that correlated with most of the variation in the bird community. I found no direct relationship between neighborhood age and bird diversity and abundance. The results demonstrate that the wealthier neighborhoods have more native species of birds and that these species increase in abundance as the socioeconomic status of the neighborhood improves. With two thirds of the globe's population expected to dwell in cities by 2030, more and more people will grow up surrounded by a depauperate community of birds, and this could adversely affect the way they perceive, appreciate, and understand nature. Ultimately, as city birdlife diminishes and urban dwellers become dissociated from the natural diversity it represents, popular support for preserving and restoring such diversity may wane, allowing ecological conditions to further erode.
Key words: Biodiversity, gradient analysis, mean family income, socioeconomic variables, spatial segregation, urban ecology