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Arnaud Da Silva, J. M. S., Emmi Schlicht, Mihai Valcu, Bart Kempenaers. (2014). Artificial night lighting rather than traffic noise affects the daily timing of dawn and dusk singing in common European songbirds. Behavioral Ecology, 25(5), 1037–1047.
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Dominoni, D. M., Carmona-Wagner, E. O., Hofmann, M., Kranstauber, B., & Partecke, J. (2014). Individual-based measurements of light intensity provide new insights into the effects of artificial light at night on daily rhythms of urban-dwelling songbirds. J Anim Ecol, 83(3), 681–692.
Abstract: Summary
The growing interest in the effects of light pollution on daily and seasonal cycles of animals has led to a boost of research in recent years. In birds, it has been hypothesized that artificial light at night can affect daily aspects of behaviour, but one caveat is the lack of knowledge about the light intensity that wild animals, such as birds, are exposed to during the night.
Organisms have naturally evolved daily rhythms to adapt to the 24-h cycle of day and night, thus, it is important to investigate the potential shifts in daily cycles due to global anthropogenic processes such as urbanization.
We captured adult male European blackbirds (Turdus merula) in one rural forest and two urban sites differing in the degree of anthropogenic disturbance. We tagged these birds with light loggers and simultaneously recorded changes in activity status (active/non-active) through an automated telemetry system. We first analysed the relationship between light at night, weather conditions and date with daily activity onset and end. We then compared activity, light at night exposure and noise levels between weekdays and weekends.
Onset of daily activity was significantly advanced in both urban sites compared to the rural population, while end of daily activity did not vary either among sites. Birds exposed to higher amounts of light in the late night showed earlier onset of activity in the morning, but light at night did not influence end of daily activity. Light exposure at night and onset/end of daily activity timing was not different between weekdays and weekends, but all noise variables were. A strong seasonal effect was detected in both urban and rural populations, such as birds tended to be active earlier in the morning and later in the evening (relative to civil twilight) in the early breeding season than at later stages.
Our results point at artificial light at night as a major driver of change in timing of daily activity. Future research should focus on the costs and benefits of altered daily rhythmicity in birds thriving in urban areas.
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Issad, S. M., Benhafri, N., El Allali, K., Farsi, H., Ouali-Hassenaoui, S., & Dekar-Madoui, A. (2021). Effects of prolonged night-time light exposure and traffic noise on the behavior and body temperature rhythmicity of the wild desert rodent, Gerbillus tarabuli. Chronobiol Int, in press.
Abstract: The aim of this study was to demonstrate for the first time in Tarabul's gerbils (Gerbillus tarabuli), the effects of simultaneous exposure to two major environmental stressors – light and noise pollutions – on the body temperature rhythm and anxious behavior. Seven groups, each consisting of 6 adult male gerbils, were subjected to a standard LD cycle (12 L:12D) with lights on at 08:00 h and off at 20:00 h, constant conditions (total darkness, DD), prolonged nighttime exposure to light (PEL: 18 L:6D) with lights on at 08:00 h and off at 02:00 h, mimicking prolonged exposure to light pollution in peri-urban areas, exposure to auditory stress (TNS) of 80 dB, and conditions combining PEL&TNS. The body temperature circadian rhythm was recorded, and behavioral tests were performed at the end of experimental phases. The results revealed the existence, for the first time in Gerbilus tarabuli, of an endogenous circadian rhythm of body temperature with a period of 23.8 +/- 0.04 h. Prolonged exposure to light at night (PEL) induced a significant phase delay (02 h 09 min +/- 0.16 h) of the rhythm, with an acrophase (peak time) occurring at 04:42 +/- 0.13 h instead of 02:33 +/- 0.21 h. Exposure to TNS for 4 hours per night induced a significant increase of the amplitude of the rhythm and a decrease of the rhythm regularity (robustness of 73.26% in TNS vs. 82.32 in control condition). While combining TNS and PEL significantly delayed the phase of the Tb rhythm by 3 h 10 min (acrophase at 06:39 +/- 0.37 h instead of 02:33 +/- 0.21 h), increased the amplitude, and significantly reduced the stability of the rhythm (robustness of 67.25% in PEL&TNS vs. 82.32 in control condition). PEL&TNS and TNS environments induce an important stress in gerbils highlighted by a significant decrease of the number of line crossings and time spent in the center area of the open field test. Furthermore, elevated plus maze test revealed gerbils of the PEL&TNS and TNS conditions significantly visited the lowest number of open arms and spent a shorter amount of time in it. In addition, these conditions were responsible for less activity (total number of entries in arms) than in the control and PEL conditions. These results indicate clearly that in the desert area, peri-urban light and noise pollutions disturb the circadian rhythm components and alter the behavior of Tarabul's gerbils inducing an anxious state.
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Leveau, L. M. (2020). Artificial Light at Night (ALAN) Is the Main Driver of Nocturnal Feral Pigeon (Columba livia f. domestica) Foraging in Urban Areas. Animals (Basel), 10(4).
Abstract: Artificial light at night (ALAN) is one of the most extreme environmental alterations in urban areas, which drives nocturnal activity in diurnal species. Feral Pigeon (Columba livia f. domestica), a common species in urban centers worldwide, has been observed foraging at night in urban areas. However, the role of ALAN in the nocturnal activity of this species is unknown. Moreover, studies addressing the relationship between ALAN and nocturnal activity of diurnal birds are scarce in the Southern Hemisphere. The objective of this study is to assess the environmental factors associated with nocturnal activity of the Feral Pigeon in Argentinian cities. Environmental conditions were compared between sites where pigeons were seen foraging and randomly selected sites where pigeons were not recorded foraging. Nocturnal foraging by the Feral Pigeon was recorded in three of four surveyed cities. ALAN was positively related to nocturnal foraging activity in Salta and Buenos Aires. The results obtained suggest that urbanization would promote nocturnal activity in Feral Pigeons. Moreover, nocturnal activity was mainly driven by ALAN, which probably alters the circadian rhythm of pigeons.
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Newport, J., Shorthouse, D. J., & Manning, A. D. (2014). The effects of light and noise from urban development on biodiversity: Implications for protected areas in Australia. Ecol Manag Restor, 15(3), 204–214.
Abstract: Global population growth and associated urban development are having profound effects on biodiversity. Two major outcomes of expanding development that affect wildlife are light and noise pollution. In this paper, we review literature reporting the effects of light and noise on biodiversity, and assess implications for conservation planning in Australia. Our results clearly indicate that light and noise pollution have the potential to affect the physiology, behaviour and reproduction of a range of animal taxa. Types of effects include changes in foraging and reproductive behaviours, reduction in animal fitness, increased risk of predation and reduced reproductive success. These could have flow-on consequences at the population and ecosystem levels. We found a significant gap in knowledge of the impact of these pollutants on Australian fauna. To reduce the effect of light and noise pollution, there needs to be careful planning of urban areas in relation to protected areas, and for biodiversity more generally. Potential measures include strategically planning the types of development and associated human activities adjacent to protected areas, and the use of shields and barriers, such as covers for lights or the use of dense native vegetation screens, while still allowing movement of animals. Changes in government standards and regulations could also help to reduce the impacts of light and noise pollution.
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