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.
