Some species which had died out in Switzerland are returning, either of their own accord, or under scientific control – although they are not always welcomed by the population. The programme to reintroduce the lynx has been particularly controversial; the aim is to bring the animal back to the north east, but most of those released have died or disappeared.

Less controversial is the return of the bearded vulture, which died out around the end of the 19th century. The first captive-bred birds were released in the Swiss National Park in 1991, as part of a European venture which started with releases in Austria in 1986. Although some pairs are breeding successfully, more need to be released in order to ensure the survival of the population.

A great popular success was the reintroduction of the ibex in 1906. This was not done scientifically: the very first were two young animals smuggled over the mountains from Italy, after the Italian king, Victor-Emmanuel II, had categorically refused to sell any to Switzerland and banned their export. Other animals were subsequently acquired, also illegally. A century later there are some 14,000 living in the Swiss Alps. However, since they are all descended from a very small stock of smuggled animals, there are fears lest at some point the effects of interbreeding will show.

Two large carnivores have tentatively reintroduced themselves. Wolves, which died out in the second half of the 20th century, have reappeared in Switzerland, although only as isolated individuals. The first was sighted in Canton Valais in 1995.

The last bear was shot in Switzerland in 1904, but in August 2005 a brown bear caused a stir when it appeared in Canton Graubünden; it subsequently left Swiss territory and all traces of it disappeared at the end of September, leaving specialists to presume that it was dead. Two more young bears appeared in Graubünden in 2007.