Dramatischer Rückgang der Auerhuhnpopulation Tetrao urogallus im Schwarzwald
Auteurs : Coppes (Joy), Ehrlacher (Judith), Müller (Gerrit), Roth (Klaus), Schroth (Karl-Eugen), Förschler (Marc), Braunisch (Veronika) et Suchant (Rudi)
Année de publication : 2019
Publication : Vogelwarte
Volume :
57
Pagination : 115-122
Résumé :
Capercaillie (Tetrao urogallus) are considered as indicator species of species rich, open conifer dominated forests and still occur over large parts of their natural range. In Western- and Central Europe populations are mainly restricted to mountain ranges, many of them are declining or became extinct. In the Black Forest, South-Western Germany, the population was first estimated based on lek counts across the entire mountain range in 1971, since 1983 this census was performed yearly. In addition, since 1988, all sightings of capercaillie are collated on a 5-year basis, to map the capercaillie distribution. The lek counts clearly reveal a negative population trend: While a total of 570 males were counted in 1971, only 167 males were counted in 2018. This decline is not evenly distributed across the Black Forest. The subpopulations in the Eastern Black Forest (Baarschwarzwald) and the Southern Black forest decreased most (from 48 males in 1993 to 8 males in 2018 and from 160 males in 1993 to 26 males in 2018, respectively). The Central Black Forest subpopulation remained stable with 11 lekking males. The Northern Black Forest subpopulation first increased (from 130 lekking males in 1993 to 197 in 2008) and decreased afterwards to 122 males in 2018. The distribution area decreased from 607 km2 in the period from 1989 to 1993 to 344 km2 from 2014 to 2018. The loss of distribution area was recorded for all subpopulations, but was largest for the Baarschwarzwald subpopulation. The causes of the decline still remain unclear and might include habitat deterioration due to changes in the forestry regime.