The forest areas and wetlands, which once used to be vast, currently are limited in their range as a result of human activity and transformation of the Earth’s surface. Through the acquisition of new areas for agricultural land and progressive development, the area of the most valuable flora and fauna habitats has been reduced and existing habitats have been divided into small patches isolated from each other. This is the phenomenon of the environmental fragmentation in which the special role is currently played linear infrastructure and, above all, highways.

Individual species of animals most often move repeatedly along the same areas – with which they are familiar with and which guarantee their safety. Large predators migrate for many years along traditional routes. This was used in the studies related to the arrangement of corridors – an analysis of the course of the migration routes of wolves and lynx in the 20th century, and the changes in the distribution of these species allowed to restore the network of forest ecological corridors for entire Poland (Jędrzejewski et al. 2001). In 2005, at the request of the Ministry of the Environment, a project of ecological corridors connecting the European Ecological Network Natura 2000 in Poland was developed (Kern et al. 2005). The basis for their demarcation was an analysis of the environment and of the current and historical distribution as well as migration of the selected indicator species: European bison, elk, deer, bear, wolf and lynx.