Blue light attracts nocturnally migrating birds

Abstract

Light pollution is increasing and artificial light sources have great impacts on animals. For migrating birds, collisions caused by artificial light pollution are a significant source of mortality. Laboratory studies have demonstrated that birds have different visual sensitivities to different colors of light, but few field experiments have compared birds’ responses to light of different wavelengths. We used 3 monochromatic lights (red, green, and blue) and polychromatic yellow light to study the impact of wavelength on phototaxis at 2 gathering sites of nocturnally migrating birds in Southwest China. For both sites, short-wavelength blue light caused the strongest phototactic response. In contrast, birds were rarely attracted to long-wavelength red light. The attractive effect of blue light was greatest during nights with fog and headwinds. As rapid urbanization and industrialization cause an increase in artificial light, we suggest that switching to longer wavelength lights is a convenient and economically effective way to reduce bird collisions.

The State of Migratory Landbirds in the East Asian Flyway: Distributions, Threats, and Conservation Needs

“…There are ample opportunities for continued work to identify routes under threat, geographical connectivity, habitat use and key stopover areas, all of which have direct implications for conservation (Runge et al, 2014;McKinnon and Love, 2018). Indeed, several projects have been established to track the migration of some species (Townshend, 2019) aided by novel field techniques, such as the use of sound (Senda et al, 2018) and blue light (Zhao et al, 2020) to attract birds, which have increased the number of birds ringed during migration.…”

Seasonal associations with light pollution trends for nocturnally migrating bird populations

“…Unlike previous lighting technology, LED provides greater flexibility in the choice of spectral composition, creating opportunities to reduce the adverse effects of ALAN. For example, different ALAN spectral compositions can affect the level of disorientation and attraction that occurs during nocturnal migration (Poot et al, 2008; Rebke et al, 2019; Zhao et al, 2020). Different ALAN spectral compositions can also affect lay date (de Jong et al, 2015), the level of daily activity patterns (de Jong et al, 2017), and energy expenditures (Welbers et al, 2017).…”

The spectral composition of a white light influences its attractiveness to Culex pipiens mosquitoes

“…Reducing the amount of short wavelength light in white LEDs may result in fewer insects approaching houses. It may also benefit other wildlife, such as migrating birds and turtle hatchlings, who are also attracted to short‐wavelength bands and may become lost, injured or killed upon approaching lights (Rivas et al, 2015; Zhao et al, 2020). Having a lower ratio of short: high wavelength bands may also have the added benefit of reducing human sleep disorders and eye disease, as short wavelength light has a larger effect on circadian rhythms and is more damaging to the retina (Grimm et al, 2001; Lockley et al, 2003).…”