Metsahallitus has organized an effective monitoring project of the Finnish Gyrfalcon population since the late 1990s for conservational purposes. During recent years all known territories have been controlled systematically, and new nest-sites have been searched for continuously. Territories have been controlled throughout the year to prevent disturbance and robbing of eggs and young. Except for a few tree-nesting pairs, practically all regularly occupied territories (22–32 per year) have been found. The number of pairs starting to nest, as well as the breeding success, varies considerably from year to year, probably mostly due
to density of the Willow Grouse Lagopus lagopus. The number of nestlings per occupied territory fluctuated from 0.91 to 2.00 in 2000–2005.