Meeting Abstract
The natural nighttime environment is increasingly illuminated by electric lighting, which causes a concurrent increase of novel challenges for wildlife. Light pollution is associated with changes in circadian, reproductive, and social behavior, but we currently lack knowledge on whether these organisms also suffer from health problems. We used a worldwide unique network of field sites artificially illuminated with white, green, and red light to monitor nighttime activity of adult great tits, Parus major, and related their nighttime behavior to within-individual changes in physiological measures. Individuals roosting in the white light treatment had higher activity and corticosterone concentrations than in the other treatments. We found that oxalic acid, with low concentrations as an indicator of sleep debt, decreased from March to May for individuals with higher activity at night. Our results indicate that white light at night increases nighttime activity levels, sleep debt, and affects hormone levels in a free-living songbird.
