A clearer picture of biodiversity is emerging across the West Estonian islands
The West Estonian Archipelago Biosphere Reserve marked two important milestones on 27 March 2025: the 35th anniversary of UNESCO recognition and the start of the second season of nature observations.
During 2025, local residents submitted a total of 2,556 nature observations across the islands. Observers ranged in age from 22 to 72, showing that interest in nature and biodiversity spans generations. The largest number of observations came from Saaremaa Municipality with 1,330 records, followed by Hiiumaa Municipality with 1,123. A further 94 observations were made in Muhu Municipality and 9 in Vormsi Municipality, while no new observations were recorded from Ruhnu this time. The most active period was spring, when biodiversity becomes more noticeable after the long winter.
A particularly valuable part of the dataset comes from the mapping of protected species. In total, 858 observations concerned protected species, including 9 records of Category I species, 164 of Category II species, and 685 of Category III species. These data provide important input for conservation work, helping experts understand where species occur and which areas may require greater attention.
Among the most frequently recorded species in 2025 was the red wood ant, observed 137 times. It was followed by the common toad with 64 observations and the common crane with 50. Other commonly recorded species included moose (45), red fox (43), grass snake and roe deer (34 each), common adder and European mantis (27 each), and globeflower (24).
This kind of citizen science contribution is highly valuable: every observation helps improve our understanding of species distribution and biodiversity on the islands. The organisers extend their sincere thanks to everyone who took part. Prizes raffled among all 2025 participants will soon be delivered to the winners.
The new observation season is already underway. In 2026, nature enthusiasts are once again invited to join the challenge “Discover the Biodiversity of the West Estonian Islands 2026”, which runs from spring until the end of the year.
This year, special attention will be given to observations of the hedgehog, Estonia’s animal of the year; the brown bird’s-nest orchid, the orchid of the year; magpie and rook nests; and nesting sites of the common swift, this year’s bird of the year, as well as swallows. In spring, participants are also encouraged to record locations of primroses. Observations can be submitted using the Nature Observations mobile app, which allows users to record both common and rare species, as well as animal tracks, calls and other signs of activity.
More information is available on the citizen science projects page of the Nature Web section of Estonia’s Environmental Portal. The challenge is organised by the activity centres of the West Estonian Archipelago Biosphere Reserve in cooperation with the Estonian Environment Agency. Thematic prizes will once again be raffled among all participants.
Now entering its third year, the challenge is producing increasingly valuable results. While individual observations show where species are found, data collected over several years also reveal broader patterns: when species arrive, how their distribution changes over time, and which places are becoming richer or poorer in species. This continuity is what makes citizen science especially important. Each new observation is no longer just a single record, but part of a larger story about the nature of the West Estonian islands.
The challenge aims to raise awareness of the islands’ natural values and encourage more people to spend time in nature and notice the biodiversity around them. Every observation — whether of a common toad on a road, a primrose on a ditch bank, or a grass snake among stones — adds another piece to the shared picture of local nature.
Time spent in nature allows us to notice more than we first expect. Sometimes a single observation can help us better understand something much larger. Biodiversity is not only important for conservation — it also directly supports human well-being by providing an environment that promotes rest, health and quality of life. In the new season, everyone has the opportunity to contribute.
Follow updates via the Facebook page of the West Estonian Archipelago Biosphere Reserve.
Citizen science project “Discover the Biodiversity of the West Estonian Islands 2026” on Nature Web (NB! page originally in Estonian): https://loodusveeb.ee/et/themes/harrastusteaduse-projektid/avasta-laane-eesti-saarte-elurikkus-2026
