Cloud cover amplifies the sleep-suppressing effect of artificial light at night in geese

In modern society the night sky is lit up not only by moon but also artificial light devices. Both of these sources can have a major impact on wildlife physiology and behaviour. For example, number bird species were found to sleep several hours less under full compared new similar sleep-suppressing effect has been reported for at (ALAN). Cloud cover modulate levels perceived wildlife, yet, in opposite directions ALAN moon. While clouds will block light, it may reflect amplify increases glow urbanized areas. As consequence, cloud effects different directions. this study we therefore measured barnacle geese (Branta leucopsis) semi-natural conditions relation phase, cover. Our analysis shows that, during nights stronger was indeed associated with increased our site. contrast, fairly constant, presumably because moonlight clear or reflected cloudy nights. Importantly, caused an estimated 24.8% reduction amount night-time NREM from medium cover, particularly when unaffected light. conclusion, findings suggest that can, rather dramatic way, immediate wildlife. Sleep appears be highly sensitive good indicator its biological effects.