To conserve biodiversity in Switzerland, habitats need to be connected to each other. For wildlife, it is essential for the migration corridors used by species to stay ecologically intact. Habitat fragmentation due to urbanisation and transport routes is a major problem for many species, especially for species that have large home ranges such as deer, wild boar and lynx. The state of wildlife corridors is a good indicator of the permeability of Switzerland’s territory for large animals.
Of the 304 corridors inventoried in 2012, only 80 are intact. As over 57% of the corridors have noticeably to heavily affected functionality, and over 16% can no longer be used by large animals, the state of wildlife corridors is rated negatively.
The changes in wildlife corridors observed between 2001 and 2012 reveal a generally stable situation, in which some have deteriorated and others have improved. Accordingly, the states of 12 corridors have improved noticeably, while 20 others have deteriorated significantly (change of category). The cause of their deterioration most often cited by the cantons is the increase in traffic on roadways in the canton. Urbanisation also places a great deal of pressure on wildlife corridors. Notable improvements are due essentially to the construction of wildlife crossings.
Therefore, the overall situation of wildlife corridors did not improve from 2001 to 2012. The restoration measures that have been applied since 2005, mainly in connection with the national road network, have not sufficiently compensated for the clearly negative trend experienced by all wildlife corridors.
There is no comparable indicator in neighbouring countries.
The location, the perimeter and the functionality of wildlife corridors of supra-regional importance were determined in collaboration with the cantons on the basis of surveys of game wardens and hunting administrators, permeability models and statistics on hunting and road accidents involving wildlife. Based on their functionality, the corridors are divided into three separate categories: intact, disturbed or highly fragmented. Corridors that fall in the “intact” category are functional. The functionality of “disturbed” corridors is noticeably to heavily affected, while "highly fragmented" corridors can no longer be used by wildlife.