Dim Nighttime Light Disrupts Songbird Sleep and Melatonin Production
“Even dim nighttime light has been shown to fragment sleep patterns in songbirds and reduce melatonin production, which affects basically everything from immune function to how alert and capable the bird is during the day. Da Silva et al. (2015) found that these timing disruptions showed up across a lot of common European species, so it does not seem like just a problem for particularly sensitive birds.”
Summary
Dim nighttime illumination (as low as 5 lux) has been shown to fragment sleep and reduce melatonin levels in songbirds such as zebra finches and European blackbirds. Research by Da Silva et al. (2015) documented similar timing disruptions across a wide range of common European songbird species, indicating the effect is not limited to unusually sensitive birds. These physiological changes are linked to broader impacts on immune function and daytime alertness.
Sources 57 searched
- Sleep in unnatural times: illuminated night negatively affects sleep and associated hypothalamic gene expressions in diurnal zebra finches - PMC
We investigated the effects of ... absolute darkness or of 5 lux dim light for three weeks. dLAN fragmented the nocturnal sleep in reduced bouts, and caused sleep loss as evidenced by reduced plasma oxalate levels....
- Effects of dim artificial light at night on locomotor activity, cardiovascular physiology, and circadian clock genes in a diurnal songbird - PMC
Dominoni DM, Goymann W, Helm B, Partecke J, 2013. Urban-like night illumination reduces melatonin release in European blackbirds (Turdus merula): implications of city life for biological time-keeping of songbirds. Front. Zool 10, 60.
- Light, Sleep and Performance in Diurnal Birds - PMC
Light is detected by photoreceptors ... to 480 nm, 460 to 470 nm, and 460 nm of light, respectively [47]. Detection of light by these photoreceptors can alter the expression of clock genes and suppress melatonin, a hormone that is important for synchronizing (or entraining) the ...
- Artificial light at night affects sleep behaviour differently in two closely related songbird species - ScienceDirect
ALAN has been shown to disrupt animal physiology, e.g. levels of melatonin, testosterone, haptoglobin and nitric oxide (e.g. Bedrosian et al., 2011, Dominoni et al., 2013a, Schoech et al., 2013, Jones et al., 2015, Russ et al., 2015, Raap et al., 2016a, Raap et al., 2016c), as well as animal behaviour (reviewed in Swaddle et al., 2015). For example, ALAN causes changes in the timing of singing behaviour in songbirds (Miller, 2006, Kempenaers et al., 2010, Nordt and Klenke, 2013, Da Silva et al., 2014, Da Silva et al., 2015; but see Da Silva et al., 2017), changes daily activity patterns (e.g.
- Night melatonin levels affect cognition in diurnal animals: Molecular insights from a corvid exposed to an illuminated night environment - ScienceDirect
In corvids exposure to dim light at night reduced the secretion of melatonin, a hormone involved in regulating the circadian rhythm, and led to cognitive impairment (Buniyaadi et al., 2022).
- Synergistic effect of light and noise pollution on dawn and dusk singing behavior of urban European blackbird: Changes during nesting season - ScienceDirect
As light is the proximate factor ... 2015), birds inhabiting habitats with high levels of artificial light usually begin vocalizing in the morning earlier than do those individuals inhabiting areas with little or no artificial light (Miller, 2006, ...
- Light pollution alters the phenology of dawn and dusk singing in common European songbirds - PubMed
Artificial night lighting may influence the perception of day length, and may thus affect both circadian and circannual rhythms. Over a 3.5 month period, from winter to breeding, we recorded daily singing activity of six common songbird species ...
- Light pollution prolongs avian activity | Science
A. Da Silva, M. Valcu, B. Kempenaers, Light pollution alters the phenology of dawn and dusk singing in common European songbirds. Philos. Trans. R. Soc. B 370, 20140126 (2015).
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