Researchers at Beersheba’s Ben-Gurion University of the Negev have pioneered a first-of-its-kind spatial model that maps how road noise disrupts animal behavior, with the study finding that nearly half of Israel’s open spaces may be compromised as viable nesting habitats. Published in the journal People and Nature in the article “Effect distances of road traffic noise on wildlife behavior,” the research shows how the reach of traffic noise stretches far beyond the road itself and into habitats that are supposed to remain intact. **Who Pays for the Roads** The study was conducted by Yael Lehnardt and Dr. Gopal Murali, under the supervision of Prof. Uri Roll and Prof. Oded Berger-Tal from BGU’s Jacob Blaustein Institutes for Desert Research. By analyzing extensive scientific literature and spatial data, the team estimated the spatial cost of traffic noise across an entire country. The model focused specifically on birds, but Lehnardt said, “Roads are key drivers of contemporary soundscapes, as they fragment natural environments while linking human activity centers.” She said, “We don’t have much research on all kinds of noises combined. There have been many studies on jet plane noise and sirens in many Western countries. Not only birds are affected – all animals including reptiles, birds, and mammals, can hear if they have ears. But if they don’t, they feel the vibrations and sense their environment. There are also lab experiments showing that loud, spontaneous sounds cause cortisol, the stress hormone, to be produced in the brain.” Lehnardt added, “The Iran-Israel War has been a very bad time for animals, as the breeding season is now.” She said animals that have to choose where to feed and rest are exposed to traffic noise not just on highways outside cities but also on streets inside them, though the study excluded urban centers because there are so many other noises there. She also said some animals may get accommodated to the noise pollution, but it can even shorten their lives and prevent them from reproducing. **What the Map Shows** The team set 5 km. as a threshold for impacts on various mammal species, many of which exhibit avoidance behavior up to that distance. For birds, the distance of impact seemed to be shorter, with avoidance of breeding habitats observed up to three kilometers from roads. The researchers found that traffic noise negatively impacts bird nesting across 42% of Israel’s non-urban environments, making these areas significantly less attractive for breeding. Even within legally protected nature reserves and national parks, 23% of the territory is not actually protected from the intrusive reach of noise pollution. The long-range nature of road noise means it disrupts key behaviors, including communication and predator detection far beyond the visible footprint of the road itself. Lehnardt said, “While we can model and map physical noise levels, those measurements don’t tell us directly how an animal experiences its environment. By adapting soundscape mapping – a method usually used by urban planners to measure human subjective experience – we can finally see the world from the perspective of the animals.” She said she would not have chosen the subject if she thought it was hopeless, adding, “The technology to reduce road noise exists; we just need the policy shift and targeted management to apply it to wildlife conservation. This map is one more tool we have never had before.” She said noise can be reduced with trees and other vegetation and physical barriers, and that there is some regulation in Germany that protects the natural environment from loud traffic, but there is no such protection in Israel’s nature parks or one authority that is responsible for supervision and enforcement. Lehnardt added, “There’s a well-known gazelle park in Jerusalem, and they’re obviously disturbed not only by traffic from a nearby busy road, but certainly from the sirens and explosions from the missiles.” She also said, “Even in Iran, there have been studies on road traffic and how it affects gazelles there.” **What They Call Protection** The researchers suggest that noise mitigation technologies, often used to protect human residential areas, must be integrated into environmental planning to protect biodiversity. Solutions include improved road maintenance, strategic landscape design, and prioritizing acoustic corridors in areas of high ecological value. Lehnardt said, “The fact that nearly half of our non-urban environments are losing their appeal to nesting birds should be a wake-up call for authorities.” She also said, “Road traffic noise is shaped by the types of infrastructure, the number of vehicles passing in a day, the surrounding topography, weather conditions including temperature, wind speed and wind direction, and how much vegetation is present. Individual animals may tolerate certain noise levels while foraging but not during the rearing of young. These complexities underscore the need to consider physical, biological and temporal aspects when evaluating the influence of noisy infrastructures on wildlife or the impact distance of noise.”
