Data Zone
The site was identified as internationally important for bird conservation in 2007 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.
Populations meeting IBA criteria ('trigger species') at the site:| Species | Red List | Season (year/s of estimate) | Size | IBA criteria |
|---|---|---|---|---|
| Greylag Goose Anser anser | LC | winter (2006) | 4,000–6,000 birds | A4i, B1i, C3 |
| Smew Mergellus albellus | LC | winter (2006) | 50–100 birds | C2 |
| Common Crane Grus grus | LC | breeding (2006) | 10–15 pairs | C6 |
| Eurasian Bittern Botaurus stellaris | LC | breeding (2006) | 20–25 pairs | B2, C2, C6 |
| Black Tern Chlidonias niger | LC | breeding (2006) | 5–20 pairs | C6 |
| Common Tern Sterna hirundo | LC | breeding (2006) | 308 pairs | C6 |
| Osprey Pandion haliaetus | LC | breeding (2006) | 35–50 pairs | B2, C6 |
| Western Marsh-harrier Circus aeruginosus | LC | breeding (2006) | 20–25 pairs | C6 |
| White-tailed Sea-eagle Haliaeetus albicilla | LC | breeding (2006) | 4–5 pairs | B2, C6 |
| Black Woodpecker Dryocopus martius | LC | breeding (1984) | 8–10 pairs | C6 |
| Year | Protected Area | Designation (management category) | % coverage of IBA |
|---|---|---|---|
| 1900 | Lindön | Naturreservat (IV) | 1 |
| 1900 | Tedarön | Naturreservat (V) | 1 |
| 1900 | Kalvholmen | Naturreservat (Ia) | <1 |
| 1959 | Björnön | Naturreservat (IV) | <1 |
| 1968 | Söderfjärden | Naturreservat (V) | 1 |
| 1985 | Asköviken | Nature Reserve (IV) | 1 |
| 1985 | Lilla Skorven | Wildlife and Plant Sanctuary (-) | <1 |
| 1987 | Sundbyholm | Naturvårdsområde (V) | 1 |
| 1990 | Frösåker | Naturreservat (IV) | 1 |
| 1991 | Tidö | Nature Reserve (IV) | 1 |
| 1993 | Sundängen | Naturreservat (IV) | <1 |
| 1994 | Fullerö | Naturreservat (IV) | <1 |
| 2006 | Askholmen | Naturreservat (IV) | <1 |
| 2008 | Ridö-Sundbyholmsarkipelagen | Naturreservat (V) | 16 |
| 2008 | Torparudden | Naturreservat (Ia) | <1 |
| 2010 | Skutteröarkipelagen | Naturreservat (IV) | 1 |
| 2010 | Skäret | Naturreservat (IV) | <1 |
| 2012 | Ridö-Sundbyholmsarkipelagen | Naturreservat (V) | 8 |
| 2012 | Asköviken-Tidö | Naturreservat (IV) | 2 |
| 2012 | Lill-Skorvliden | Naturreservat (IV) | - |
| 2013 | Ängsö | Naturreservat (IV) | 21 |
The Local Conservation Group(s) listed below are working to conserve this IBA.
| Name | Year formed |
|---|---|
| Västmanlands ornitologiska förening | 0 |
| Habitat | % of IBA | Habitat detail |
|---|---|---|
| Wetlands (inland) | 75 | Standing freshwater; Water fringe vegetation |
| Forest | 15 | Broadleaved deciduous woodland; Mixed woodland; Native coniferous woodland |
| Artificial/Terrestrial | 5 | Arable land |
| Grassland | 5 | Humid grasslands |
| Land use | % of IBA |
|---|---|
| hunting | 100 |
| tourism/recreation | 90 |
| fisheries/aquaculture | 75 |
| nature conservation and research | 35 |
| agriculture | 5 |
| urban/industrial/transport | 5 |
| forestry | minor (<10) |
| military | minor (<10) |
| water management | minor (<10) |
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Western part of Lake Mälaren (Sweden). Downloaded from
https://datazone.birdlife.org/site/factsheet/western-part-of-lake-mälaren-iba-sweden on 23/12/2024.