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Location Japan, Niigata
Central coordinates 139o 14.00' East  37o 50.00' North
IBA criteria A4i, A4iii
Area 310 ha
Altitude 0 - 5m
Year of IBA assessment 2004

Wild Bird Society of Japan

Site description Lake Hyoko in Niigata Prefecture was meant to be a farm pond. As the numbers of the wintering swans are increasing, it has been enlarged. It is Hyoko Suikin Koen (Hyoko Waterbirds Park) now and has an area of 30 ha. There are paddy fields around Hyoko where ducks and swans forage. The Aganogawa river flows at the southwestern direction of Hyoko, and Tundra Swans roost on a sandbar along the river. Nelumbo nucifera and Euryale ferox grow in the lake, and Phragmites australis extend at northeastern side of the lake. Prunus x yedoensis was planted around the lake, and hydrophites grow in Ayameike pond.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Northern Pintail Anas acuta winter  2004  present  A4i  Least Concern 
Tundra Swan Cygnus columbianus winter  2004  present  A4i  Least Concern 
Mallard Anas platyrhynchos winter  2004  present  A4i  Least Concern 
A4iii Species group - waterbirds winter  2004  min 20,000 individuals  A4iii   

IBA Monitoring

2010 low not assessed low
Poor - based on little, or potentially unreliable/unrepresentative, data

No known threats no known threats happening now whole area/population (>90%) no or imperceptible deterioration low

Whole area of site (>90%) covered by appropriate conservation designation  A management plan exists but it is out of date or not comprehensive  Unknown  low 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Hyo-ko Wetlands of International Importance (Ramsar) 24 protected area contained by site 24  


IUCN habitat Habitat detail Extent (% of site)
Wetlands (inland) Freshwater lakes and pools  -

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Lake Hyoko. Downloaded from on 24/10/2016

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