Effect of artificial light at night on sleep and metabolism in weaver birds

Abstract

Artificial light at night is constantly minimizing the span of dark nights' from the natural lightdark cycle of earth. Over the past century, the 'lightscape' of earth has completely changed owing to technological advancements which subsequently changed the lifestyle of human as well as the nearby animal species. This motivated the present study, wherein we investigated the impact of light at night (LAN) on behavior and physiology of a diurnal passerine finch, baya weaver (Ploceus philippinus). A group of bird (N=10) exposed to 12L:12D photoperiod was initially subjected to dark nights (0 lux) for a period of 10 days followed by 5 lux; night light for a span of 4 weeks. First week in LAN served as acute treatment with respect to fourth week (chronic). Acute exposure had more pronounced impact on the behavioral and physiological observations when compared with chronic treatment. The results reveal significant increase in nighttime activity, sleep loss, significant inclusion of drowsiness behavior during the day in response to LAN. Beside these behavioral alterations, changes in physiological parameters such as; reduction in body mass, loss of gradient between pre-and post-prandial blood glucose levels, elevation in plasma corticosterone levels were more prominent during acute exposure of LAN.Plasma metabolites such as triglycerides, total protein, serum glutamic-oxaloacetic transaminase (SGOT) and creatinine concentrations also hiked in response to LAN treatment. Thus, the study broadly enumerates the impact of acute and chronic exposure of LAN on behavior (rest/sleep) and physiology (metabolism) of birds'.

What happens when the lights are left on? Transcriptomic and phenotypic habituation to light pollution

“…Two other studies exposed birds to 4 weeks of ALAN, with one reporting a persistent behavioral response 45 and the other a slight decline over time. 46 In the present study, and in our previous work, 21 , 28 we have noticed daily variation in zebra finch activity underlying longer term trends. As such, it could be that the longer-term trend we report here is robust and less likely to have been influenced by random fluctuation in activity than previous work, 46 or that responses vary across species.…”

Exposure to outdoor artificial light at night increases risk and burden of metabolic disease in Ningxia, China

“…The associations between outdoor ALAN and metabolic disease presence are biologically plausible. Both exposure studies on humans and animal have shown that nocturnal light may alter metabolic homeostasis by disrupting the circadian system (Fonken and Nelson 2014;Ishihara et al 2021;Yadav et al 2022). Light is the most efficient synchronizer of the circadian system.…”

Food monotony compromises photoperiod induced responses in migratory redheaded bunting

“…Food intake: Food intake was measured for two consecutive cycles of 24h each, wherein the base of the cage was covered with a paper sheet and a weighed quantity of food was provided in food cups. 24,25 After 48h, the food remaining in bowl and the spillage along with the faecal matter was collected back and weighed after removing the faeces. The difference between food supplied and food recovered gave the amount of food consumed i.e.…”