Table (Supplementary material) Waterfowl congregation in wintering sites where H5N1 has been recorded in 2005-2006.

Country / Area / Recorded waterfowl aggregation / References
CzechRepublic / ˇCeske´ Budeˇjovice / Twelve infected mute swans were found in the district of Ceske´ Budeˇjoviceˇ at the bank of Vltava river. It is know that this region has a high proportion of mute swans during the winter because the Vltava-river is not frozen in this area. /

Nagy et al., 2007

Denmark / Baltic sea and inner Danish waters / Birds infected with HPAI H5N1 have been found in areas where the densities of wild ducks and swans are normally high during winter/early spring (i.e. mainly the coastal line toward the Baltic sea and shallow areas in the inner Danish waters). / Danish Veterinary and Food Administration, 2007
France / Dombes region / In February 2006 densities of mute swans in infected ponds were 6 times higher than those in non-infected ponds, while densities of Anatidae in infected ponds were 3 times higher than non-infected ones. / Hars et al., 2008
Germany / Baltic Sea -Island of Ruegen / In February 2006 crowding of mixed species of water birds was observed in ice-free water holes on the island of Ruegen. / Globig et al., 2009
Republic of Serbia / Vojvodina (north-western Serbia) / From 1999 to 2004 a field study was carried out at the fishponds of Kolut situated at the edge of Kolut village, Vojvodina province. The fishponds were covered with ice from December to mid-February. During this period waterfowl were absent from the area and concentrated on the Danube - the only unfrozen water body. Large flocks of mute swans appeared immediately after the ice melted, from mid-February, and disappeared from the Danube. Ponds are preferred habitats as they are probably richer in food. Kolut lies at approximately 10 km from the locations of two reported outbreaks: in Serbia on 28.02.2006 and in Croatia on 3.03.2006. / Tucakov, 2005 and Tucakov pers. com.
Slovenia / Drava river / The River Drava is the largest river to flow through Slovenia. There is an Important Bird Area (IBA) located between Maribor and Središèe ob Dravi on the Croatian border. Mid-winter counts carried out from 1999 to 2003 recorded a concentration of approximately 23,000 waterfowl on the river each year. / Stumberger, 1999, 2000, , 2001, 2002, 2005
Switzerland / LakeCostance / LakeConstance has a particular significance as a resting and wintering area for water birds and is the most important inland body of water for water fowl in Germany, Switzerland and Austria. During February 2006 a total of 160,000 water birds were counted at the lake, mostly comprising coots, tufted ducks and mallards, whereas 1600 mute swans and 616 whooper swans were registered. / Globig et al., 2009
Ukraine / Crimea peninsula / A mass passage of white-fronted geese and other waterfowls was observed from 19 to 25 November. Approximately15,000 white-fronted geese stopped over in the Sivash and were counted from 21-26 November, shortly before a major epizooty of H5N1 was recorded. / Atkinson et al., 2006

Full references:

Atkinson PW, Clark JA, Delany S, Diagana CH, du Feu C, FiedlerW, et al. (2006) Urgent preliminary assessment of ornithological data relevant to the spread of Avian Influenza in Europe. In: Report to the European Commission, Delany S, Veen J, Clark JA (editors), Study contract: 07010401/2005/425926/MAR/B4

Danish Veterinary and Food Administration (2007) Highly pathogenic avian influenza H5N1 in Denmark, Spring 2006- Report. Available: Accessed 22 March 2008

Globig A, Staubach C, Beer M, Koppen U, Fiedler W, Nieburg M,et al. (2009) Epidemiological and ornithological aspects ofoutbreaks of highly pathogenic avian influenza virus H5N1 of Asian lineage in wild birds in Germany, 2006 and 2007.Transboundary Emergency Disease 56:57–72

Hars J, Ruette S, Benmergui M, Fouque C, Fourneir J, Legouge A, et al. (2008) The epidemiology of the highly pathogenic H5N1avian influenza in mute swan (Cygnus olor) and other Anatidae in the Dombes region (France), 2006. Journal of Wildlife Disease 44:811–823

Nagy A, Machova J, Hornickova J, Tomci M, Nagl I, Horyna B, Holko I (2007) Highly pathogenic avian influenza virus subtype H5N1in mute swans in the CzechRepublic. Veterinary Micro-biology 120:9–16

Stumberger B (1999) Results of the mid-winter waterfowl counts in January 1999 in Slovenia. Acrocephalus 20:6–22

Stumberger B (2000) Results of the mid-winter waterfowl counts in January 2001 in Slovenia. Acrocephalus 21:261–274

Stumberger B (2001) Results of the mid-winter waterfowl counts in January 2001 in Slovenia. Acrocephalus 22:171–174

Stumberger B (2002) Results of the mid-winter waterfowl counts in January 2002 in Slovenia. Acrocephalus 23:43–47

Stumberger B (2005) Results of the mid-winter waterfowl counts in January 2001 in Slovenia. Acrocephalus 26:99–103

Tucakov M (2005) Numbers and seasonal activity of the mute swan (Cygnus olor) on the Kolut fishpond (NW Serbia). Ring 27:221–226