The site was identified as important in 2000 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.Populations meeting IBA criteria ('trigger species'):
|Species||Current IUCN Red List Category||Season||Year(s)||Population estimate at site||IBA criteria met|
|Black Tern Chlidonias niger||LC||breeding||1996-1998||30-35 breeding pairs||B2|
The current IUCN Red List category may differ from that which was valid at the time of IBA criteria assessment (2000).
|Habitat (IUCN level 1)||Habitat detail||Extent (% of site)|
|Wetlands (inland)||Standing freshwater, Water fringe vegetation||-|
|Artificial/Terrestrial||Highly improved re-seeded landscapes||-|
|Land-use||Extent (% of site)|
BirdLife International (2023) Important Bird Area factsheet: Lake Kasonys and adjacent wetlands. Downloaded from http://datazone.birdlife.org/site/factsheet/lake-kasonys-and-adjacent-wetlands-iba-lithuania on 02/10/2023.