Habitat selection by capercaillie in summer and autumn: Is bilberry important?

Abstract

Abstract. The use of habitat by female and male adult capercaillie Tetrao urogallus during summer and autumn was studied by comparing the distribution of radio locations of birds with the availability of habitat at forest stand, home range and landscape level in an area of the Bavarian Alps, Germany. Capercaillie preferred forests with structural features typical of their main distribution range, the boreal forest: they selected large patches of old forest with moderate canopy cover of about 50%, and a well developed field layer with high proportions of bilberry Vaccinium myrtillus. Hens selected both home ranges and sites within home ranges in old forest. Ranges selected by cocks did not differ from availability in the study area, but they preferred old forest within their ranges. The size of home ranges was negatively related to bilberry cover both in hens and cocks. The distribution of bilberry also determined habitat use by capercaillie at the landscape scale. The study demonstrated that bilberry is the major determinant of the selection of habitat by capercaillie in landscapes with sparse and fragmentary cover of ericaceous shrubs, such as central Europe.

Home range, habitat selection and activity patterns of an arid-zone population of Temminck’s ground pangolins, Smutsia temminckii

“…One possible explanation concerns the uniform geology and climate at the Kalahari study site (Mucina & Rutherford 2006) presumably resulting in a fairly uniform ant community (Pietersen 2013;Pietersen et al, in prep.). As prey availability is one of the major driving forces behind habitat selection (Langvatn & Hanley 1993;Storch 1993;Alcala-Galvan & Krausman 2013), this uniformity probably invalidates habitat selection as there would be no energetic gain in selecting specific habitats if all have similar prey communities (Langvatn & Hanley 1993;Edwards et al 2002). This lack of selectivity may also be attributable to the individual vegetation types in the Kalahari being more extensive than those in Swart's (1996) study (Mucina & Rutherford 2006), with individual home ranges thus incorporating fewer vegetation types.…”

Habitat and survival of capercaillie Tetrao urogallus nests and broods in the Bavarian alps

“…Elevations vary between 700 and 1800 m. The lower slopes (<1000 m) include 51% of the area; 42% belong to the upper slopes (1000-1300 m), the range with the best bilberry Vaccinium myrtillus cover (Storch, 1993a). Only 7% of the area is above 1300 m altitude.…”

“…Glutz v. Blotzheim, 1973;Muller, 1974;Klaus et al, 1986). The proportion in the diet varies among studies (Kastdalen & Wegge, 1985;Spidsti & Stuen, 1988) and was not known on Teisenberg, but broods and single adults used habitats rich in anthills (Storch, 1993a). In adult capercaillie from Teisenberg, ants remained a minor component of the diet (Schwarzmiiller, 1990).…”

“…Because of the birds' large spatial requirements (Storch, 1993a; this study), both local habitat structure and landscape mosaic should be considered. Thinning and the creation of edges and gaps will favour the field layer in dense forests; bilberry develops best in stands with canopy cover of about 50% (Storch, in press).…”

Forest as Capercaillie’s habitat: applied research efforts and new management experiences

“…La specie è considerata come indicatrice delle foreste di conifere naturalmente rade, con elevate proporzioni di popolamenti vecchi e aperti: inoltre, notoriamente preferisce habitat ricchi di arbusti di Ericaceae, in particolare di mirtillo (Vaccinium myrtillus -Storch 1993a, Storch 1993b, Bollmann et al 2005a. Recentemente, il Gallo cedrone è stato documentato come specie-ombrello per un'elevata diversità delle comunità ornitiche sulle Alpi svizzere (Suter et al 2002) e possibilmente sui Pirenei francesi (Macabiau et al 2005).…”