Scientific publications

In 1982, the Raptor Grid, a nation-wide programme for monitoring both diurnal and nocturnal "common" birds of prey was started by the Finnish Ringing Centre. Voluntary ringers were asked to select a 10 x 10 km study plot and find annually all active nests or at least locate occupied territories of birds of prey from their study plot (annual total has averaged 120). Since 1986, additional information has been collected with the Raptor Questionnaire. After that, more than 40,000 potential nest sites of birds of prey have been checked annually. During 1982–2005, most of the Finnish populations of birds of prey remained on the same general level, although the annual fluctuations of vole specialists have been extensive. In the Honey Buzzard Pernis apivorus, Goshawk Accipiter gentilis, Common Buzzard Buteo buteo and Eagle Owl Bubo bubo the population trend has been negative during several years. In contrast, the populations of Kestrel Falco tinnunculus and Pygmy Owl Glaucidium passerinum have increased steeply due to extensive nest box projects. International cooperation is needed to monitor nomadic species.