Open AccessThe 37-year dynamics of a subalpine passerine bird community, with special emphasis on the influence of environmental temperature and Epirrita autumnata cycles
Author(s) -
Anders Enemar,
Bengt Sjöstrand,
Gerhard Andersson,
Ted von Proschwitz
Publication year - 2004
Publication title -
ornis svecica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.104
H-Index - 14
eISSN - 2003-2633
pISSN - 1102-6812
DOI - 10.34080/os.v14.20236
Subject(s) - passerine , montane ecology , ecology , species richness , betula pubescens , geography , biology
The breeding passerine bird community of 9 km2 of a primeval subalpine birch forest in Swedish Lapland was censused yearly from 1963 through 1999. The community density remained stable, fluctuating around a mean value of 403 ± 85 territories/km2. Species richness increased by an average of one species every four years. Twenty species made up 98% of the community and Phylloscopus trochilus (40%) and Fringilla montifringilla (19%) remained the dominant species. The species turnover rate between successive seasons was on average 30%. The mean temperatures in June and July were positively correlated to the community density two years and one year later, respectively, less so for the densities of the individual species. Fringilla montifringilla increased in density during the first two years of each Epirrita autumnata caterpillar outbreak, whereas the other species responded only weakly or not at all. All species tended to fluctuate in parallel (no significant opposite trends) which together with the other results suggests that the investigated bird community is far from saturated.