Mag. Myriam Promberger

PDF im Hochschulschriften-Service der Universität Wien

The conservation status of capercaillie and black grouse in the South-eastern Alps.

Outdoor activities, which have become increasingly popular in the last decades, often lead to a conflict with the needs of wild animals. As consequence, a substantial number of species are threatened and endangered due to tourism and recreational activities. In this study we tried to relate increasing human disturbance and changes in forest cover to changes in populations of black grouse Tetrao tetrix and capercaillie Tetrao urogallus on the level of hunting districts in the state of Styria, Austria.

Therefore, we distributed questionnaires to Styrian hunters to collect semi-quantitative data on spatiotemporal changes in the distribution of both grouse species as well as on changes in winter and summer tourism, and forest cover in hunting districts. For the decades 1990-1999 and 2000-2009, changes in grouse populations, and sources of human disturbance (hiking, mountain biking, ski hiking, snowshoe hiking) had to be ranked by the heads of hunting districts on a scale between -3 (strong decline) and +3 (strong increase), changes in the extent of forest clearings and windbreaks, and forest road density had to be ranked on scale between 0 (no change) and +3 (strong increase). Hunting districts were grouse populations vanished are located predominantly at the South-eastern margin of the species’ alpine distribution ranges. Both capercaillie and black grouse showed a continuous population decline in the study period from 1990-2009, while tourism, forest clearings and windbreak areas increased.

A model selection approach provided weak evidence that in time period 1990-2009 windbreaks had a positive effect and increasing forest road density had a negative effect on black grouse. In capercaillie, increased forest clearing areas appeared to have a weak positive effect. These results indicate that both grouse species may benefit from processes acting against forest maturation, at least when taking place on small spatial scales. Furthermore, our data provides evidence that recreational activities in summer (hiking + mountain biking) negatively affected black grouse and capercaillie. To stop the overall decline of both grouse species in Styria, visitor management measures, particularly in sensitive regions, may be important to reduce the negative effects of human disturbance on grouse populations.