Forest grouse populations decline sharply in Kainuu and Northern Ostrobothnia, Finland

In Finland’s eastern regions, particularly in Kainuu and Northern Ostrobothnia, the populations of forest grouse have significantly declined this summer, as indicated by game triangle surveys, according to a report from the Natural Resources Institute. In Lapland, populations have also decreased. Conversely, in other parts of Finland, forest grouse populations have remained stable or slightly increased, especially in Southern Finland, where the numbers of black grouse and capercaillie have seen some growth.

Andreas Lindén, a specialist at the Natural Resources Institute, points out that forest grouse populations typically experience considerable regional fluctuations. Areas with the steepest declines now had seen growth and relatively abundant populations in recent years. For instance, the current changes in the black grouse population align with the species’ typical 6–7 year cycle, as the previous low year in many regions was in 2017.

In Lapland, when reviewing the entire province, all forest grouse species have experienced a downturn, but regional variations are significant. The density of capercaillies has decreased by 15% over the past year, yet remains close to five individuals per square kilometer. Only Satakunta and Uusimaa boast larger densities.

Within the province, the density varies significantly; in the area managed by the Pellon game management association, the density was eight birds per square kilometer, whereas in Tervola it was 4.42. The capercaillie population in Pellon increased by over 30%, while it decreased nearly as much in Tervola.