• Summary
• Text
• Details
• Map
• Resources

The site was identified as internationally important for bird conservation in 2002 because it was regularly supporting significant populations of the species listed below, meeting IBA criteria.

Populations meeting IBA criteria ('key species') at the site:

Species	Red List	Season (year/s of estimate)	Size	IBA criteria
Whooper Swan Cygnus cygnus	LC	winter (1990–2000)	130–197 individuals	C2, C6
Common Goldeneye Bucephala clangula	LC	passage (1990–2000)	2,700–3,056 individuals	B1i, C3
Red-crested Pochard Netta rufina	LC	breeding (1990–2000)	100–150 breeding pairs	B2
Red-crested Pochard Netta rufina	LC	passage (1990–2000)	5,500–10,803 individuals	A4i, B1i, C3
Common Pochard Aythya ferina	VU	passage (1990–2000)	32,000–44,450 individuals	A4i, B1i, C3
Ferruginous Duck Aythya nyroca	NT	breeding (1995)	1 breeding pairs	C6
Tufted Duck Aythya fuligula	LC	passage (1990–2000)	34,000–53,672 individuals	A4i, B1i, C3
Northern Shoveler Spatula clypeata	LC	passage (1990–2000)	2,100–3,846 individuals	B1i, C3
Gadwall Mareca strepera	LC	passage (1990–2000)	6,500–11,667 individuals	A4i, B1i, C3
Northern Pintail Anas acuta	LC	non-breeding (1990–2000)	550–983 individuals	B1i, C3
Common Teal Anas crecca	LC	passage (1990–2000)	4,200–11,000 individuals	B1i, C3
Little Grebe Tachybaptus ruficollis	LC	non-breeding (1990–2000)	700–1,102 individuals	A4i, B1i, C3
Spotted Crake Porzana porzana	LC	breeding (1990–2000)	5–15 breeding pairs	C6
Spotted Crake Porzana porzana	LC	passage (1993–2000)	20 individuals	C6
Little Crake Zapornia parva	LC	breeding (1990–2000)	3 breeding pairs	C6
Eurasian Coot Fulica atra	LC	non-breeding (1990–2000)	47,070 individuals	A4i, B1i, C3
Eurasian Bittern Botaurus stellaris	LC	breeding (1990–2000)	1 breeding pairs	C6
Eurasian Bittern Botaurus stellaris	LC	passage (1993–2000)	9 individuals	C6
Common Little Bittern Ixobrychus minutus	LC	breeding (1990–2000)	5–7 breeding pairs	C6
Black-crowned Night Heron Nycticorax nycticorax	LC	breeding (1990–2000)	1 breeding pairs	C6
Great White Egret Ardea alba	LC	passage (1993–2000)	9 individuals	C6
Ruff Calidris pugnax	LC	non-breeding (1990–2000)	537 individuals	C6
Wood Sandpiper Tringa glareola	LC	passage (1990–2000)	80 individuals	C6
Black Tern Chlidonias niger	LC	passage (1993–2000)	200 individuals	C2, C6
Common Tern Sterna hirundo	LC	breeding (1990–2000)	67 breeding pairs	C6
Western Marsh-harrier Circus aeruginosus	LC	breeding (1990–2000)	3–5 breeding pairs	C6
Western Marsh-harrier Circus aeruginosus	LC	passage (1993–2000)	10 individuals	C6
Hen Harrier Circus cyaneus	LC	winter (1990–2000)	32 individuals	C6
Black Kite Milvus migrans	LC	breeding (1993–2000)	10–30 breeding pairs	C6
A4iii Species group - waterbirds	n/a	non-breeding (1990–2000)	48,857–49,692 individuals	A4iii, C4
A4iii Species group - waterbirds	n/a	passage (1991–2000)	87,318–138,812 individuals	A4iii, C4

Year	Protected Area	Designation (management category)	% coverage of IBA
-	Untersee of Lake Constance	Ramsar Site, Wetland of International Importance (-)	13
1938	Halbinsel Mettnau	Naturschutzgebiet (IV)	2
1938	Bodenseeufer	Landschaftschutzgebiet (V)	1
1938	Wollmatinger Ried - Untersee - Gnadensee	Naturschutzgebiet (IV)	13
1941	Stehlwiesen	Naturschutzgebiet (IV)	<1
1951	Bodenseeufer	Landschaftschutzgebiet (V)	<1
1954	Insel Reichenau	Landschaftschutzgebiet (V)	1
1958	Hornspitze auf der Höri	Naturschutzgebiet (IV)	3
1961	Bodenseeufer (Gmk. Gaienhofen, Horn, Gundholzen)	Naturschutzgebiet (IV)	2
1961	Bodenseeufer (Gmk. Öhningen)	Naturschutzgebiet (IV)	6
1961	Bodenseeufer (Gmk. Iznang, Moos, Böhringen)	Naturschutzgebiet (IV)	1
1961	Bodenseeufer (Gmk. Wangen, Hemmenhofen)	Naturschutzgebiet (IV)	1
1961	Bodenseeufer (Gmk. Allensbach, Hegne, Reichenau)	Naturschutzgebiet (IV)	<1
1973	Radolfzeller Aachried	Naturschutzgebiet (IV)	5
1980	Wollmatinger Ried - Untersee - Gnadensee	Landschaftschutzgebiet (V)	<1
1982	Bodenseeufer auf Gemarkung Markelfingen	Naturschutzgebiet (IV)	<1
1996	Radolfzeller Aachmündung	Naturschutzgebiet (IV)	1

Habitat	% of IBA	Habitat detail
Forest	-	Alluvial and very wet forest
Grassland	-	Steppes and dry calcareous grassland; Humid grasslands; Mesophile grasslands
Shrubland	-
Wetlands (inland)	-	Standing freshwater; Water fringe vegetation

Land use	% of IBA
fisheries/aquaculture	-
tourism/recreation	-

---

Recommended citation
BirdLife International (2025) Important Bird Area factsheet: Untersee of Lake Constance (Germany). Downloaded from https://datazone.birdlife.org/site/factsheet/untersee-of-lake-constance-iba-germany on 19/01/2025.