U.S. Desert Songbirds at Risk in a Warming Climate
Projected increases in the frequency, intensity and duration of heatwaves in the desert of the southwestern United States are putting songbirds at greater risk for death by dehydration and mass die-offs, according to a new study.
Researchers used hourly temperature maps and other data produced by the North American Land Data Assimilation System (NLDAS)—a land-surface modeling effort maintained by NASA and other organizations—along with physiological data to investigate how rates of evaporative water loss in response to high temperatures varied among five bird species with differing body masses. Using this data, they were able to map the potential effects of current and future heat waves on lethal dehydration risk for songbirds in the Southwest and how rapidly dehydration can occur in each species.
Researchers homed in on five songbird species commonly found in the desert southwest: lesser goldfinch, house finch, cactus wren, Abert's towhee and the curve-billed thrasher.
Under projected conditions where temperatures increase by 4 degrees Celsius (7 degrees Fahrenheit), which is in line with some scenarios for summer warming by the end of the century, heatwaves will occur more often, become hotter, and expand in geographic range to the point where all five species will be at greater risk for lethal dehydration.
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Photo via NASA - Goddard Space Flight Center.