The genetic legacy of multiple beaver reintroductions in Central Europe.

The comeback of the Eurasian beaver (Castor fiber) throughout western and central Europe is considered a major conservation success. Traditionally, several subspecies are recognised by morphology and mitochondrial haplotype, each linked to a relict population. During various reintroduction programs in the 20th century, beavers from multiple source localities were released and now form viable populations. These programs differed in their reintroduction strategies, i.e., using pure subspecies vs. mixed source populations. This inhomogeneity in management actions generated ongoing debates regarding the origin of present beaver populations and appropriate management plans for the future. By sequencing of the mitochondrial control region and microsatellite genotyping of 235 beaver individuals from five selected regions in Germany, Switzerland, Luxembourg, and Belgium we show that beavers from at least four source origins currently form admixed, genetically diverse populations that spread across the study region. While regional occurrences of invasive North American beavers (n = 20) were found, all but one C. fiber bore the mitochondrial haplotype of the autochthonous western Evolutionary Significant Unit (ESU). Considering this, as well as the viability of admixed populations and the fact that the fusion of different lineages is already progressing in all studied regions, we argue that admixture between different beaver source populations should be generally accepted.

Notoedric and sarcoptic mange in free-ranging lynx from Switzerland.

Between March and December 1999, five free-ranging lynx (Lynx lynx) affected by mange were found dead or shot by game wardens in the Swiss Alps. In the first two cases, Notoedres cati was isolated from the skin; in the third and fourth case, Sarcoptes scabiei was the cause of the infection; and in the fifth case, a mixed infection was diagnosed. Red foxes (Vulpes vulpes) affected with sarcoptic mange and domestic cats infested with N. cati are likely to be the sources of infection. It seems improbable that mange will occur as an epidemic in lynx in Switzerland, but losses due to infections with N. cati and/or S. scabiei may have an impact on this small, geographically limited lynx population. This is the first report of notoedric mange in a free-ranging lynx and the first report of mange in lynx from Switzerland.