Ökologie, Verhalten und Schutz des Haselhuhns Tetrastes bonasia im Böhmerwald (Šumava, Tschechien)
Auteurs : Klaus (Siegfried) et Ludwig (Tobias)
Année de publication : 2018
Publication : Charadrius
Volume :
54
Fascicule : 2-3
Pagination : 119-128
Résumé :
Since 1972 the distribution, abundance and habitat use of Hazel Grouse has been studied in a 100 km2 area of the Bohemian Forest (Šumava, Czech Republic). Along fixed routes (80 km) reactions of the grouse to imitations of the males territorial song as well as indirect indications (dust bathing sites, feathers, droppings, tracks) were recorded. Hazel Grouse densities varied between 2.4 and 5.4 home ranges/km2. No statistical significant trend in numbers was found within 44-years of the study, but during the last 4 years the index of density declined by about 30%. Frequency of occupancy of home ranges was highest in habitats rich in alder (79%), followed by habitats rich in birch and/or hazel (64%), beech (59%), and rowan (49%). These differences were statistically significant (0.01 < p < 0.05, Fisher’s problem test). By modelling habitat requirements we found: Site occupancy by hazel grouse in the Bohemian Forest was high in dense spruce forests characterized by short sighting distances (20-40 m). It increased sharply with small proportions of deciduous trees (5-10%) in a conifer-dominated forest and remained high at ground vegetation height (20-50 cm). Other elements that were positively associated with hazel grouse site occupancy were the presence of anthills and dead wood (fallen logs), and higher crown closure. Hazel grouse site occupancy decreased with a higher proportion of grass cover but was positively influenced by higher proportions of herbs and bilberry. Conservation strategies should favour multilayered mixed forests with gaps and preservation of pioneer trees in spruce plantations.