More than two thousand animals are run over per year - and these are only the reported accidents, the real number is much higher. A new study examined how the characteristics of the road affect the trampling of animals, and what can be done to reduce the number of tramplings
By Rakfat Gross, Zwata - Science and Environment News Agency
Not only migratory birds. Most animals leave the territory where they were born and migrate between seasons from one habitat to another, for a variety of reasons - for the needs of culture, searching for food, finding new territory and more. On their way from here to there, many animals are forced to cross roads throughout the country. Many of them, too many, find their death on these roads: in the last decade more than 600 deer have been run over to death in Israel. For comparison, as of the end of 2021, The total deer population in Israel is about 6,400 individuals. A total of about 2,000 incidents of animal trampling per year are reported to the authorities on average, but the real number is much higher - and tens of thousands of wild animals are trampled in Israel every year.
What can be done to reduce the number of stampedes and is it possible to plan, pave and widen roads in a way that will allow all of us - humans and animals - to reach our desired district safely? A study led by Dror Danbom, a doctoral student who studies ecological connectivity inLaboratory for Human and Biodiversity Research At the Faculty of Architecture and Urban Planning at the Technion, he precisely tested the effect of road characteristics on animal trampling. The study was presented last week In the 50th Annual Conference on Science and the Environment.
There are solutions to the problem of wild animal migration and trampling that are common in the world and in Israel, such as special fencing on the side of the road to prevent the animals from crossing and risking being run over, and the creation of ecological crossings above or below the road. However, the costs of building such fences, as well as creating ecological transitions, are very high. In Israel they did this mainly on main roads, along most of road 6, on road number 1 and more. But many of the roads in Israel do not have such crossings and/or fences. Those who pay the price are the animals.
"The trampling of animals has two negative effects," says Danboom, whose research is his doctoral thesis (supervised by Prof. Assaf Schwartz of the Technion and Dr. Avi Bar-Masda of the University of Haifa), "it prevents the animals from moving from one area to another, causes them to stay in their place and so The ecological connectivity is damaged, as well as the resilience and health of the population. In addition, when it comes to species on the brink of extinction in Israel, such as the otter, every trampling is a significant harm to the population".
Looking for the dead roads
In a study conducted over the past two years, Danbom examined which road characteristics cause more run-overs. "We travel on different roads," he explains, "one has a separation barrier, the other has fencing on the side of the road, the number of lanes changes, so does the state of lighting, and more; The first question we asked is how these characteristics affect the amount of trampling by animals of different species. Another question we asked: does the traffic load affect the amount of trampling. That is, is there a difference between roads where the traffic is sparse and busy roads".
About 20 years ago, a Swedish ecologist named Andreas Seiler Put forward a theory according to which the amount of tramplings in low and high traffic loads will be low, and in medium traffic loads the amount of tramplings will be maximum. The reason: in low traffic loads animals will be able to cross without being run over, in high traffic loads they will avoid being run over, and in the middle we will see most of the tramplings.
"I tested this theory in depth", explains Denboom. "I had trampling data from the Nature and Parks Authority, which collected more than 20 reports over a 10-year period, and on average more than 2,000 tramplings per year, when in practice the number is greater because not everything is reported. The study was conducted on 20 species of wild animals, which had the highest number of tramplings (100 tramplings or more) out of trampling reports on 288 different species of amphibians, reptiles, mammals and birds. In addition, Danboom entered into the model the characteristics of 2,846 kilometers of roads, and data of traffic loads in Israel from the Central Bureau of Statistics, on roads where the load varies from 300 cars per day to 148 thousand cars per day. "I took the data", says Denboom, "I built a statistical model and checked whether Seiler's theory holds in practice."
When a wild boar and a rock rabbit cross the road
The answer Denbom discovered was that reality is much more complex than theory, and how could it not be? Although in some cases a trampling pattern similar to that proposed by Seiler was indeed observed, such as in the striped hyena and the gray wolf, but in most species other patterns were found. After all, the animals are different from each other and react differently to different road features - the pig does not cross the road like the rabbit and the deer does not react like the fox. The jackal is used to the presence of humans and the noise of cars, but the rock rabbit is not. Some animals freeze in front of car lights, some run away. Each animal crosses the road on its own terms.
Danboom gives them signs: "Animals that are preyed upon, like a rabbit, are very fearful and will run away from any noise. There are less apprehensive animals, such as wild boars, which do not react significantly to human disturbances, including cars. In contrast, foxes or small rodents freeze in the face of danger - and will be run over in most cases. Many animals, such as insects or reptiles, do not have the ability to perceive an approaching car, and so on."
Danbom tested one of the known solutions, a barrier in the center of the road, and found that the disadvantages outweigh the advantages. It is true that there are species of animals that are deterred by the barrier, but "such a barrier", explains Danboom, "makes it very difficult for an animal that enters the road to escape. The barrier has two essentially negative effects - either the barriers prevent the animals from moving to a habitat on the other side, or they increase the chance that they will be run over. Therefore, at least from an ecological point of view, it is better to avoid separation in the middle of the road."
Meet at the bus station
Where do the stampedes take place? "It's always customary to think that the places that need to be treated are the busy, big roads," says Danboom, "but according to the research's conclusions, quite a few run-ins also happen on small roads with little traffic that are in open areas, such as in the Golan Heights, where there are a lot of run-overs relative to the roads Others in Israel". Regarding the lighting on the roads at night, Danboom says, "We discovered that lighting helps in reducing trampling, but only for porcupines, rabbits and partridges".
"Another interesting thing we discovered," says Danboom, "is related to bus stops. Some species have significantly more trampling near bus stops. The theory is that bus stops are an attraction; They usually have a tin, which attracts the animals that dig for food. In addition, a station is a place where cars and buses pull over to the side of the road, which increases the chances of being run over."
"It is good to take into account the information collected and also take into account the welfare of the animals the next time a new road is paved", Danboom concludes.
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