Population trends of the Dotterel Charadrius morinellus in Finland during the past 150 years

Abstract

The population trends of the Finnish Dotterel were studied for the past 150 years. A comprehensive study of Finnish ornithological literature was undertaken, the main bird archives were worked through and additional data were gathered through personal correspondence. Thus an almost complete coverage of the published observations was obtained, augmented by many previously unpublished records. The number of observations was fairly stable up to the mid-twentieth century, the slight apparent increase being mostly due to an increase in the numbers of bird-watchers. In reality the numbers probably decreased. The peak abundance was most likely in the 1880s. The main reason for the subsequent decline was obviously overhunting. In the 1950s the Dotterel was still fairly numerous; a decrease probably started sometimes during the 1950s-1960s, although little published information is available. At the main Finnish study area (Värriötunturi fells) the number of breeding pairs has dropped dramatically since the early 1970s. The main reason for the recent decline is probably the use of pesticides in the wintering area . During the Finnish ornithological history the number of Dotterel have decreased to 1-10% of the original, perhaps even more. As no exact data were available for the Dotterel it was not included in the "Red Data Book" of Finland. The data presented in this report suggests that it would belong at least to the category "in need of monitoring". The Dotterel is listed in the EC Directive on the Conservation of Wild Birds (Directive 79/409/EEC).