Biodiversity decline detected in bird observations 1981–2018 around the islands of Seili, the Archipelago Sea, SW Finland

  • Jari Hänninen University of Turku
  • Miro Pietilä University of Turku
  • Katja Mäkinen University of Turku
  • Jasmin Inkinen University of Turku

Abstract

Bird sightings have been documented during the years 1981–2018 on the Seili and nearby islands in the Finnish Archipelago Sea, northern Baltic Sea. In this study, trends in sightings of bird species / groups and families or orders were classified as increasing, stable, decreasing or sporadic (random) based on monthly observation data. A total of 213 species were noticed in monitoring. Many species and groups declined during the study period, taxonomically 65 % of the bird families or orders showed decreasing abundances for over half or more than half of their species. The decline in bird diversity was evident also in the community composition of bird groups which has been narrowed down during the study period. Only a few species showed an increasing trend, most notably the White-tailed Eagle (Haliaeetus albicilla) and the Great Cormorant (Phalacrocorax carbo sinensis). Presently many bird species spend lesser time at the area than during early observation years.

Author Biographies

Jari Hänninen, University of Turku

Archipelago Research Institute, Biodiversity Unit

Miro Pietilä, University of Turku

Department of Geography and Geology

Katja Mäkinen, University of Turku

Archipelago Research Institute, Biodiversity Unit

Jasmin Inkinen, University of Turku

Archipelago Research Institute, Biodiversity Unit

Published
2020-10-13
How to Cite
Hänninen, J., Pietilä, M., Mäkinen, K., & Inkinen, J. (2020). Biodiversity decline detected in bird observations 1981–2018 around the islands of Seili, the Archipelago Sea, SW Finland. Memoranda Societatis Pro Fauna Et Flora Fennica, 96, 38-47. Retrieved from https://journal.fi/msff/article/view/98690
Section
Articles