Forest Grouse Populations Stabilise in Finland After Years of Decline
Finland’s forest grouse populations have partially stabilised this summer following several years of decline, though regional and species-specific differences remain significant, according to the Natural Resources Institute Finland (Luke).
Nationwide, the densities of capercaillie and black grouse are close to last year’s levels and the long-term average, Yle reports. However, hazel grouse and willow grouse populations continue to show a slight decline, with willow grouse densities remaining far below the average. MTV Uutiset highlights that the situation of the willow grouse is particularly concerning in its more forested distribution areas.
Regional Variations in Population Trends
The development of grouse populations varies across the country, with a notable east–west divide. In eastern Finland—stretching from Southeast Finland to Kainuu, as well as in Northern Ostrobothnia—capercaillie populations have increased, and some local growth has also been observed in black grouse and hazel grouse (Yle, MTV Uutiset).
In contrast, western regions, including Southwest Finland, Coastal Ostrobothnia, and Southern Tavastia, have seen declines in forest grouse populations over the past year. In Lapland, most forest grouse species have decreased, with the exception of the capercaillie (Yle).
Breeding Success and Environmental Factors
A warm spring and early summer may have benefited grouse chicks by providing abundant insect food, though early nesting could have led to chicks hatching before peak food availability. Nationwide, the proportions of chicks for capercaillie, black grouse, and hazel grouse were at or slightly above last summer’s levels, indicating moderate breeding success. However, willow grouse chick numbers remained low in Lapland and Kainuu, though Northern Ostrobothnia saw an exceptionally high proportion (MTV Uutiset).
Forest grouse populations reached their lowest point in 2016–2017 before briefly recovering, but the trend has since turned downward again. While some regional improvements have been observed, no clear nationwide increase across multiple species has yet been detected (MTV Uutiset).
The findings are based on data from 826 wildlife triangles, Finland’s primary monitoring method for forest grouse populations. The results are used in game management, hunting planning, and research (MTV Uutiset).
