Avian species respond to light in a variety of ways including increased physical activity, increased immunity to sickness, hormone production, and stimulation of internal organs (Parvin et al 2014).

American Robins

Diurnal songbirds rely on light signals to initiate morning birdsong. Miller (2006) conducted a study on American robins and the relationship between timing of birdsong and artificial light pollution. He found artificial light affected the timing of birdsong at a population level, in which American robins would begin their birdsong during the night if exposed to bright artificial light (Miller 2006).

Petrels!

Petrels in the Mediterranean are greatly affected by light pollution during the fledgling stage of life in which they must navigate their flight from the sea to the nest (Rodriguez et al 2015). Light pollution fatally affected 8.5% of fledglings, and 30-47% of colonies were exposed to light polluted areas (Rodriguez et al 2015). Rodriguez et al (2015) argue that while the effect of light pollution on bird mortality seems quite low, the rapid urbanization of the area could have a detrimental impact on the survival of the Petrels long term.

Migratory Birds

Migratory birds are attracted to offshore artificial light that confuses the magnetic orientation of the birds and results in increased mortality rates (Poot et al 2008). Poot et al (2008) conducted a study targeting the blue-green light spectrum to develop artificial light alternatives that do not disrupt the magnetic orientation of migrating birds. The study was successful as the wavelengths of the lights were proven to be the variable affecting magnetic orientation disruption (Miller 2006). Birds were less disrupted by blue-green lights than by white-red lights, suggesting bird-friendly artificial light is possible (Miller 2006).

Can birds adapt to changing environments like urbanization, loss of habitat, increased predation?

Peafowl exhibit innovative behaviour due to loss of historical habitat (Yorzinski 2017). A study investigated the effects of light pollution on peafowls’ ability to innovate and showed exposure to light pollution decreased the amount of sleep per night, which in turn decreased physical activity during the day (Yorzinski 2017). The sleep deficit had a negative impact on the innovative behaviours, suggesting light pollution can adversely affect peafowl’s ability to adapt to new environments (Yorzinski 2017).