In Cumbria, UK – an area with excellent night sky quality – ecologists have mapped the effects of different levels of light pollution by tracking the singing behavior of robins. Over a period of three months, bird song samples were collected from paired sites consisting of a light site and a dark site.
Study results indicated that artificial lighting, particularly uncontrolled or unshielded lighting fixtures, induced early singing and calling in robins and other species of songbirds. Song repertoire and UV light are used by animals for mate selection and if mating strategies are altered by light levels, females run the risk of choosing less fit males.
According to Jack Ellerby, project manager for Cumbria Dark Skies, fieldwork tracing the impact of light pollution and wildlife tends to go unnoticed, as the effects on animals are more gradual than those of other pollution, such as sewage, oil spills or plastic. litter.
Although light pollution cannot be blamed for the entire change in wildlife behavior, Stephanie Holt, a bat specialist at the UK’s Natural History Museum, thinks it could be a “tipping point”. She notes that some of the most significant impacts of lighting on invertebrates are still largely unknown. “[A]s the cornerstone of all our ecosystems, we should target research and conservation in that direction,” she says.
However, lighting legislation, at least in the UK, is slow to take off, says Holt. Because few ecologists are employed at the planning authority level, artificial lighting projects are often swept to the back of the government priority pile, says Holt. However, a spokesman for the UK’s Department for Environment, Food and Rural Affairs (Defra) said the government had taken action to address the problem of light pollution in a number of areas, including through the planning system. “We continue to study the impact of artificial light on insects and biodiversity at large,” they added.
Elsewhere in the world, measures are taken to protect wildlife at night. In the Netherlands, LED public lighting systems in cities are supporting rare bat species, while France has adopted one of the most progressive light pollution policies to date. The 2018 law enshrines the technical requirements for the design and operation of outdoor lighting installations used in the public and private domain.
UK campaigners hope the first meeting of 2020 of the Dark Sky All-Party Parliamentary Group, which produced a 10-point policy plan to improve dark sky provisions, could be the country’s gateway to scrutiny artificial lighting.
In the meantime, the relay is held by individuals, who can lobby politicians and local authorities, create night corridors for wildlife and ensure that their own homes and offices do not contribute additional sources of light pollution. , explains Holt.