Ecologists investigate bird diversity
Date: March 12, 2019
Source: University of Massachusetts at Amherst
A persistent question among urban ecology researchers has been the long-term impact of urbanization on bird species biodiversity. Specifically, they wonder whether the portions of cities with higher diversity are simply exhibiting an "extinction debt" -- populations doomed to extinction but not yet disappeared -- or if other factors such as range shifts or local environmental changes play a role in changes in diversity.
Now, researchers led by co-first authors Paige S. Warren at UMass Amherst and Susannah B. Lerman of the USDA Forest Service, with Riley Andrade, Kelli Larson and Heather Bateman of Arizona State University, report on results from their long-term monitoring of birds in the Phoenix metropolitan area. Details appear in the current online issue of Ecosphere.
The study looked at bird communities over time in relation to habitat, societal factors, human responses and bird populations. Findings suggest that although the presence of bird species, bird abundance and the number of bird species all decreased over time, in areas where homeowners provided desert landscaping -- fine gravel and drought-tolerant, desert-adapted vegetation -- some desert specialist birds such as verdin and cactus wren could still be found.
The researchers also report observing socio-economic factors associated with species diversity. For example, the desert-like landscaping types and desert specialist bird species occurred more frequently in neighborhoods with higher per-capita incomes and lower percentages of renters and Hispanic/Latinx residents. Warren notes that including socioeconomic factors has become more common recently, but it's still unusual. Their earlier work "was truly ground-breaking with respect to including socioeconomic factors," she says.