Mag. Jelte Schember

PDF im Hochschulschriften-Service der Universität Wien

Habitat use of black grouse (Tetrao tetrix) at the Natura 2000 site "Niedere Tauern" (Austria).

Modeling habitat suitability has become increasingly popular in conservational science and wildlife management in recent years. For a species of conservation interest as the black grouse this approach gives researchers and conservationists the opportunity to acquire a helpful management tool. In this study we used incidence data from black grouse surveys conducted in July-August 2011 along 51 point-stop transects (mean length: 5.10 km) at the Natura 2000 site “Niedere Tauern” in Styria (Austria) to construct a habitat suitability model. Of 45 measured or estimated environmental variables only 16 variables, which proved to significantly affect black grouse occurrence, were further considered. After accounting for multi-collinearity, 10 variables remained for subsequent modeling. Effects of variables on black grouse occurrence were evaluated using a stepwise-forward and stepwise-backward model selection approach. Five explanatory variables significantly affecting occurrence of black grouse remained in the final generalized linear model: dwarf shrub cover, mean perimeter-area ratio (quantifying habitat heterogeneity within a 100 m radius), steepness of slope, topographical heterogeneity and distance to huts. Only for the last four variables GIS layers covering the whole study area were available. Therefore only these variables were subsequently used to calculate a habitat suitability map, which can be used as a preliminary tool to evaluate to what extent high quality habitat areas are covered by the currently designated area of the Natura 2000 site “Niedere Tauern”.