Evading the blues: Nocturnally active adult Leach's Storm‐Petrels show evidence of avoiding LED lights with shorter wavelengths

Abstract

Nocturnal seabirds, particularly Procellariiforms, are vulnerable to being negatively impacted by artificial lights as they are prone to encounter various forms of light pollution in coastal and pelagic habitats, leading to strandings or other changes to their normal behavior. While adopting blackout periods can be effective to mitigate the impacts at brightly lit sites, this is not always an option when human health and safety requirements during night‐time operations are a concern. We exposed adult Leach's Storm‐Petrels ( Hydrobates leucorhous ) to four light (blue, bright white, dim white, and red) and a dark (no light) treatment to investigate whether we could influence their frequency of occurrence, quantified using a thermal imaging camera, while birds were naturally active at a colony. We used a generalized linear regression to examine the relationship between the number of birds detected per minute and light treatments. The treatments of blue and bright white versus dark were significant covariates with the mean number of birds per minute detected highest during the dark treatment (1.52, LCL = 1.13, UCL = 1.91) and lowest during the blue treatment (0.93, LCL = 0.69, UCL = 1.16), suggesting avoidance to these lights. Our study adds to the growing scientific support that seabirds show a stronger sensitivity to lights with shorter wavelengths and demonstrates the potential of using blue lights as a mitigative approach to reduce adult strandings at industrial sites without compromising the safety of night‐time operators.