"You stink like a pig," we often say when we call a seriously disgusting human odour. But where do you find something that stinks to pigs? The solution is surprisingly simple. It seems that a certain displeasure is mutual and pigs are discouraged by human odor. And not just pigs.
Repellents containing a concentrated odour of human sweat are more or less repulsive to many species of wildlife. This can be used to prevent people and game from meeting in the least suitable places – on the roads.
Traffic collisions pose a serious risk not only to all animals, but also to the health and property of road users. In the period 1993–2012, a total of 30 people was killed in clashes with forest animals and domestic animals. According to statistics from the Police of the Czech Republic, the estimated damage to vehicles amounts to over CZK 2.3 billion a year. Experts from the Faculty of Forestry and Wood Sciences from the Department of Game Management and Wildlife Zoology therefore focused on research into the effectiveness and financial cost of using game-repulsive repellents on our roads, which can help prevent many damages.
The research took place for three years at the 2nd class road and the railway line around Vlašim. Every week, a patrol check of animal mortality was performed on defined sections. The first year in the absence of repellents, in the next 2 years with the application of Hagopur, Hukinol and Kornitol.
During the research, the authors walked an incredible 1,800 kilometres and found 1,208 dead animals ranging from amphibians, reptiles and birds to mammals of various sizes. The most frequent victims of traffic collisions were mainly European common frog, then common voles and hedgehogs. However, their behaviour is not affected by the tested repellents; it mainly affects medium size and large mammals. The number of killed mammals decreased after the use of repellents, especially in the second year of application, which could be due to the fact that the authors applied the experience with the application of products from the first year. By applying the repellent, a 37% reduction in total losses was achieved, including both property damage and the value of medium size and large mammals, which cause the greatest damage. Thus, the statistics do not include the values ??of other small animals, which do not cause damage to human lives or property in the event of a collision, but their death means far greater ecological damage than that of game.
Agents to repel game are one of the measures influencing their behaviour, however, their final effect depends on many other factors, such as regularity of application, weather effects, stress on game during hunting, etc. In some cases, game is motivated to crossroads for food on the other side of road. "Feeding on one's own site can also lead to a reduction in accidents, leading to a reduction in migration for food," recommends Tomáš Kušta from FLD, the first author of the study.
In some game species, more individuals are killed each year with a “motor weapon” than are hunted with a firearm. From the results of the work it can be stated that odour repellents are useful for reducing the mortality of game on the road and the consequent damage that occurs during these events. In particular, the work shows that when repellents are applied at the right time, in the right place and a suitable preparation or combination is used, their effectiveness appears to be high. In the future, the question remains how to prevent small animals from colliding with car wheels and thus reduce significant environmental impacts.
Ing. Tomáš Kušta, Ph.D.
He came to the Faculty of Forestry and Wood Sciences at the CULS in Prague in 2002 from the Secondary Forestry School in Písek. He has been working professionally in the field of game management since 2011. He focuses mainly on migration and game mortality and is currently working on the NAZV research project "Harmonization of game populations and forest ecosystems in the context of expected climate change and forest damage minimization" and the Ministry of the Environment project "Plan care for lynx, wolf and brown bear in the Czech Republic ”.
Prepared by: Jitka Krykorková