What habitat parameters are important for the survival of ground nests in mountain forests? Recommendations for protection of Hazel Grouse Tetrastes bonasia based on an experiment with artificial nests

Abstract

ABSTRACT Capsule Predation risk of artificial nests resembling Hazel Grouse Tetrastes bonasia nests was reduced in more diverse habitats and when roads and trails were closer. Aims To determine the importance of habitat structure and the presence of roads and hiking trails for the predation risk of artificial ground nests. Methods We investigated predation on artificial nests in mountain spruce forests with high tourist numbers in the Tatra Mountains, Southern Poland, in 2012–2014. Some 174 artificial ground nests resembling those of Hazel Grouse were set up and monitored. For 98 artificial nests, we compared environmental variables at two area scales, and the forest structure between predated and surviving nests. Results At the local scale (within 5 m) artificial nests were more likely to be predated at sites with lower occurrence of ferns and lying dead wood. At the wider spatial scale (within 100 m), nests were more likely to survive if near to roads and tourist trails. The occurrence of different tree species in the forest stand did not significantly influence predation rate of artificial nests. The mean daily nest predation rate was not high and varied between years (0.003–0.009). Conclusion Greater habitat diversity and the presence of roads and trails increased the survival of ground nests. These results are potentially important for conservation planning for threatened ground-nesting birds, such as the Tetraonidae.