Habitatwahl des Alpenmurmeltieres Marmota marmota (Rodentia, Sciuridae): Ein Vergleich zwischen dem Dachsteinplateau und den Hohen Tauern [Sélection de l'habitat de la marmotte alpine Marmota marmota (Rodentia, Sciuridae) : une comparaison entre le plateau de Dachstein et le Hohe Tauern].

Résumé

In two areas of the eastern Alps (Dachsteinplateau and Hohe Tauern ridge) habitat selection of alpine marmots was investigated. According to the criteria of Bibikow (1996) habitat selection was discussed in terms of protection against abiotic factors, availability of food and avoidance of predation. In the Hohe Tauern ridge marmot dens were found between 1400 m and 2700 m. These results correlate well with other studies. On the Dachsteinplateau all dens were situated below 1840 m, the lowest den was found at 1690 m. This is possibly due to the harsher climatic conditions in the northern Calcareous Alps. Marmots can therefore not settle as high on the Dachsteinplateau as in the Hohe Tauern ridge. In terms of possibilities to dig a den, we found, that in the Hohe Tauern ridge marmots prefer rubble heaps. On the Dachsteinplateau they only use moraine ridges. These preferences may depend on similar proportions of different rock sizes and fine material in the underground. Marmots feed exclusively on alpine meadows. This type of vegetation is widely distributed in the Hohe Tauern ridge. On the Dachsteinplateau it is found only in small habitat patches. Accordingly, the distribution of marmots differs between the two study areas. In the Hohe Tauern ridge marmots were distributed in an elevation belt between 2000 m and 2700 m, whereas on the Dachsteinplateau they where only found on the patches described above. Concerning predation avoidance we found in both areas that the dens are at a significant larger distance to possible fox shelter when compared to the offered habitat. The distances on the Hohe Tauern ridge were greater than those on the Dachsteinplateau. This may be a further consequence of the different habitat situations.