Grouse dynamics and harvesting in Kainuu, northeastern Finland

• Published in: Oikos
• Main Authors: Lampila, Petri, Ranta, Esa, Mönkkönen, Mikko, Lindén, Harto, Helle, Pekka
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2011
• Subjects: Ecology, Evolution, Behavior and Systematics; Kainuu; Sea ice
• Online Access: http://dx.doi.org/10.1111/j.1600-0706.2010.18788.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0706.2010.18788.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0706.2010.18788.x

We study the dynamics of the capercaillie, black grouse, hazel grouse and willow grouse in Kainuu game management district in northeastern Finland in the years 1989–2004. It appears that the 6–7 year periodicity that prevailed in this region from 1960s up to 1980s has now vanished in all species. The grouse data are modelled using a linear autoregressive model with lag terms for population dynamics including grouse harvest as annual bag and an index of winter severity (winter‐time area of Baltic Sea ice cover). We use the Akaike information criterion for selecting the best model for each species; first order lag is forced to the models. It turns out that a term is needed for harvesting (with a negative coefficient) in models for all species. For the capercaillie and the hazel grouse second order lag was included, for the black grouse and the willow grouse first order lag suffices. The willow grouse is the only species where the index of winter strength (with a negative coefficient) is needed in the model.