| argentina | buenos aires province | chroicocephalus cirrocephalus | species | 0 | 1 |
| austria | burgenland | chroicocephalus ridibundus | species | 1 | 0 |
| china | hubei | chroicocephalus ridibundus | species | 0 | 1 |
| china | yunnan | chroicocephalus ridibundus | species | 0 | 1 |
| czech republic | south moravian region | chroicocephalus ridibundus | species | 0 | 1 |
| djibouti | | chroicocephalus genei | species | 1 | 0 |
| france | | chroicocephalus ridibundus | species | 1 | 0 |
| georgia | | chroicocephalus ridibundus | species | 10 | 0 |
| georgia | guria region | chroicocephalus ridibundus | species | 8 | 0 |
| hong kong | | chroicocephalus ridibundus | species | 0 | 1 |
| iraq | saladin governorate | chroicocephalus genei | species | 1 | 0 |
| iraq | saladin governorate | chroicocephalus ridibundus | species | 2 | 0 |
| italy | campania region | chroicocephalus ridibundus | species | 0 | 1 |
| mongolia | dornod province | chroicocephalus ridibundus | species | 1 | 0 |
| netherlands | | chroicocephalus ridibundus | species | 2524 | 0 |
| norway | oslo county | chroicocephalus ridibundus | species | 2 | 1 |
| russia | astrakhan oblast | chroicocephalus genei | species | 0 | 1 |
| russia | kaliningrad oblast | chroicocephalus ridibundus | species | 0 | 1 |
| russia | kamchatka krai | chroicocephalus ridibundus | species | 1 | 0 |
| russia | magadan oblast | chroicocephalus ridibundus | species | 1 | 0 |
| sweden | kalmar | chroicocephalus ridibundus | species | 0 | 1 |
| sweden | stockholm | chroicocephalus ridibundus | species | 1 | 0 |
| tunisia | sfax governorate | chroicocephalus genei | species | 0 | 1 |
| united kingdom | | chroicocephalus ridibundus | species | 1 | 0 |
| united kingdom | england | chroicocephalus ridibundus | species | 13 | 0 |