2020 ESA Annual Meeting (August 3 - 6)

COS 231 Abstract - Let there be light: Artificial light at night promotes activity throughout the night in nesting common swifts (Apus apus)

Eran Amichai, EEES Graduate Program, Dartmouth College, Hanover, NH and Noga Kronfeld-Schor, School of Zoology, Tel Aviv University, Tel Aviv, Israel
Background/Question/Methods

The use of artificial light at night (ALAN) is a rapidly expanding anthropogenic effect that transforms nightscapes throughout the world, causing light pollution that affects ecosystems in a myriad of ways. One of these is changing or shifting activity rhythms, largely synchronized by light cues. We used acoustic loggers to record and quantify activity patterns during the night of a diurnal bird – the common swift (Apus apus) – in a nesting colony exposed to extremely intensive artificial illumination throughout the night at Jerusalem’s Western Wall. We compared that to activity patterns at three other colonies exposed to none, medium, or medium-high ALAN. Additionally, we analyzed fecal sacs obtained from the nests to learn whether the swifts have incorporated into their diet noctuid moths (Lepidoptera: Noctuidae) - a common nocturnal insect in the nesting sites that is mostly unavailable to strictly diurnal birds.

Results/Conclusions

We found that in the lower-intensity ALAN colonies swifts ceased activity around sunset, later the more intense the lighting. At the Western Wall, however, swifts remained active throughout the night. we found no evidence of noctuid moth consumption, but smaller moth consumption was evident in all three urban colonies. This shift in activity patterns may have important implications for the birds’ physiology, breeding cycle, and fitness, and may have cascading effects on their ecosystems.