Insight into how "sensory pollution" affects animals

To combat the effect of noise and light pollution on animals, researchers must first understand how animals are affected.

03/16/2020 | 1:52 PM

An international team led by ecologists Wouter Halfwerk from VU Amsterdam and Davide Dominoni from the University of Glasgow developed a new framework to understand how this type of sensory pollution affects animals. The study is published in the journal Nature Ecology and Evolution.

Human activity affects the living environment of animals in almost every conceivable way. Road systems cut through habitat and night lights make the light of the moon and stars pale. “Light pollution, such as we have here on the Zuidas from high buildings, can attract many migratory birds in bad weather conditions that fly around disoriented and eventually die from exhaustion or collisions,” says Halfwerk.

Masking, distraction and misleading
The framework shows, among other things, the presence of 'sensory danger zones', which determine where sensory contaminants overlap with the activity of animals. The researchers also defined three mechanisms that affect animal mortality and reproduction. They call these mechanisms: masking, distraction and misleading.

Traffic noise and light pollution are examples of masking, for example they occur as artificial light "covers" the glow of the moon, so that birds or insects can no longer navigate at night. Traffic noise can also be distracting, especially when animals are performing difficult tasks, such as hunting for camouflaged prey. misleading occurs when a sensory contamination "directs animals in the wrong direction or toward the wrong target," says Dominoni.

The effects of light, sound and chemical pollutants can cause reduced survival and reproduction for many organisms, but studies linking sensory pollutants to population decline are rare. The published research to define these mechanisms may be the first step in developing strategies to mitigate the negative effects of sensory pollutants that may underlie population decline.

Future solutions
"When we understand the mechanism, we may be able to come up with specific interventions and solutions to minimize the effect of pollution," says Dominoni. "For example, light has many properties. By changing some of these properties, we can very well minimize the impact of light pollution on wildlife." Think of shields that direct street lights down or build roadsides around roads to reduce road noise.

The study was conducted in collaboration with the National Park Service and supported by a grant from NASA to co-authors Neil Carter, Jesse Barber (Boise State University), Clinton Francis (California Polytechnic University), and David Stoner (Utah State University).