image: An ash-throated flycatcher perches on barbed wire. view more
Credit: Image courtesy of Dave Keeling (Emeritus, California Polytechnic State University, San Luis Obispo, CA).
A study examines the influence of chronic anthropogenic noise on bird stress and fitness. Anthropogenic noise is a pollutant that decreases environmental quality, but whether anthropogenic noise represents a chronic source of stress and decreased fitness for animals remains unclear. In northern New Mexico's San Juan Basin, home to noise-producing natural resources extraction, Nathan Kleist and colleagues studied the interactions between noise levels and the stress and fitness of three species of cavity-nesting birds. The authors found that increased noise exposure was associated with decreased baseline corticosterone level--a measure of the birds' ability to cope with stress--in adults and nestlings, suggesting that chronic anthropogenic noise may induce stress and hypocorticism in birds. Additionally, when exposed to an additional acute stress, nestlings increased their acute stress-induced corticosterone levels. The authors also found that hatching success in western bluebirds was negatively associated with noise levels, but not for mountain bluebirds or ash-throated flycatchers. Furthermore, nestlings exhibited accelerated growth of feathers and body size at medium noise levels, compared with low and high noise levels. The authors suggest that anthropogenic noise might impair environmental risk perception in species that rely on auditory cues. According to the authors, the multispecies pattern of hypocorticism in response to increased noise amplitude is linked to negative fitness, a finding with ramifications for conservation planning.
Article #17-09200: "Chronic anthropogenic noise disrupts glucocorticoid signaling and has multiple effects on fitness in an avian community," by Nathan J. Kleist, Robert Guralnick, Alexander Cruz, Christopher Lowry, and Clinton Francis.
MEDIA CONTACT: Nathan J. Kleist, University of Colorado Boulder, CO; tel: 303-847-7889; e-mail: <nathan.kleist@gmail.com>
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