Seabird Fatalities Caused by Artificial Lights

By guest writer Airam Rodríguez, postdoctoral researcher at Estación Biológica de Doñana CSIC, Spain

Human alteration of natural light levels in the environment increases every year and leads to the loss of natural nightscapes worldwide. Light pollution has generated a range of ecological impacts, but from a conservation perspective, light-induced mass fatality events are one of the most severe ecological consequences of light pollution. That is the case of nocturnal seabirds, which are attracted, disoriented, and grounded by artificial lights nearby their colonies.

Our article, “Seabird mortality induced by land-based artificial lights” published in Conservation Biology, is the result of a collaborative effort among different research groups around the world involved in the prevention of light-induced seabird fatalities. Together, we reviewed the research on light attraction, identified information gaps, and proposed measures to address the problem.

The widespread and ever-growing use of artificial light at night has exposed seabirds to an increasing threat. Burrow-nesting seabirds are attracted to, and disorientated by, artificial lights. Light-induced landings can be fatal because collisions with human-made structures (e.g. buildings, electric wires and pylons, fences, or posts) or the ground can fatally injure the birds. Even if uninjured, grounded birds may be unable to take off again and are vulnerable to predation, vehicle collisions, starvation, dehydration, or poaching.

According to our knowledge and our bibliographic search, the most affected seabirds are petrels and shearwaters, although other avian species like auklets, puffins, and eiders can be involved too. Of the 113 burrow-nesting petrel species, we found that lights can ground 56 of them, including 24 species threatened according to the International Union for Conservation of Nature (IUCN) criteria. These include the Cory’s shearwater, which is the most affected species in the world with more than 64,000 birds rescued in different locations. The Newell’s shearwater, from Hawaii, and the Barau’s petrel, from Reunion Island in the Indian Ocean, are classified by the IUCN as “Endangered” on the Red List. Also of note are the enigmatic Mascarene petrel, and also the Ringed-storm petrel, whose breeding colonies have never been located, despite the fact that birds are frequently grounded and rescued in lit areas of Peru and Chile.

To reduce light-induced mortality, the most immediate and commonly-taken actions are the rescue programs conducted by local governments, environmental organizations, or aware citizens. By rescuing grounded birds at their properties or neighborhoods, members of the public help keep vulnerable birds safe from threats. Although these programs release around 90% of rescued birds, this is not enough to overcome the threat from artificial light.

Despite being a well-known problem for decades, we are still far from completely understanding why seabirds are attracted to lights, or how to prevent this from happening. We need to improve our understanding of this human-wildlife conflict in order to design appropriate and effective management and mitigation measures. The most urgent projects we need to work on include:

estimation of mortality and impact on populations;

assessment of threshold light levels and safe distances from light sources;

documenting the fate of rescued birds;

improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of veterinary care;

research and innovation on seabird-friendly lights to reduce attraction.

Given the critical conservation status of seabirds, research on the issue is crucial. Light pollution continues to increase all over the world and is negatively impacting petrels and other seabirds. Meanwhile, the general public and local governments should help reduce attraction to light and subsequent fatality through simple actions such as dimming or turning lights off at critical times of the year.

Airam Rodríguez is a postdoctoral researcher at Estación Biológica de Doñana CSIC, Spain, thanks to a Marie Curie International Outgoing Fellowship, the 7th European Community Framework Programme (No. 330655) and a Juan de la Cierva contract, Ministry of Economy, Industry and Competitiveness, Government of Spain (IJCI-2015-23913). His project tries to look for solutions to the fatal attraction of seabirds to artificial lights (more info at http://ecolightsforseabirds.weebly.com).