Table 1. Prevalence (%) of antibodies against the flavivirus envelope protein found in yellow-legged gull eggs for all the colonies sampled.
| Country | Colony | Coordinates | Year | Prevalence |
| France | Plane (1) | 43°11′14″N-5°23′13″E | 2010 | 0 (0/8) |
| Riou (2) | 43°10′39″N-5°23′04″E | 2009 | 0 (0/32) | |
| 2010 | 0 (0/20) | |||
| Frioul (3) | 43°16′27″N-5°18′15″E | 2009 | 0 (0/32) | |
| 2010 | 0 (0/32) | |||
| Carteau (4) | 43°22′40″N-4°51′27″E | 2009 | 0 (0/32) | |
| 2010 | 0 (0/32) | |||
| 2011 | 0 (0/30) | |||
| Besson (5) | 43°29′15″N-4°27′47″E | 2009 | 0 (0/32) | |
| 2010 | 0 (0/32) | |||
| Grau-du-Roi (6) | 43°32′15″N-4°08′17″E | 2009 | 0 (0/32) | |
| Villeneuve (7) | 43°30′55.94″-3°54′2.25″E | 2009 | 3 (1/32) | |
| 2010 | 0 (0/32) | |||
| Gruissan (8) | 43°06′36″N-3°06′25″E | 2009 | 0 (0/32) | |
| 2010 | 0 (0/32) | |||
| Corrège (9) | 42°51′15″N-3°01′21″E | 2009 | 3 (1/32) | |
| 2010 | 3 (1/32) | |||
| Spain | L'Escala (10) | 42°07′32″N-3°07′58″E | 2010 | 67 (4/6) |
| Medes (11) | 42°02′50″N-3°13′21″E | 2009 | 37 (14/38) | |
| 2010 | 49 (24/49) | |||
| 2011 | 67 (33/49) | |||
| 2012 | 67 (34/51) | |||
| Ebro Delta (12) | 40°34′17″N-0°39′37″E) | 2009 | 0 (0/32) | |
| 2010 | 0 (0/29) | |||
| 2011 | 0 (0/30) | |||
| Columbretes (13) | 39°53′52″N-0°41′06″E | 2010 | 0 (0/50) | |
| Dragonera (14) | 39°35′00″N-2°19′00″E | 2010 | 0 (0/39) | |
| Isla Grossa (15) | 37°43′40″N-0°42′27″O | 2009 | 0 (0/32) | |
| 2010 | 0 (0/32) | |||
| 2011 | 0 (0/30) | |||
| Algeria | Chetaïbi (16) | 37°05′79″N, 7°17′53″E | 2009 | 0 (0/32) |
| 2010 | 0 (0/32) | |||
| Jijel (17) | 36°47′21″N, 5°36′19″E | 2010 | 3 (1/31) | |
| Skikda (18) | 36°56′15″N, 6°53′09″E | 2010 | 0 (0/17) | |
| Tunisia | Djerba (19) | 33°39′10″N-10°58′59″E | 2009 | 0 (0/32) |
| Sfax (20) | 34°42′28″N-10°45′02″E) | 2009 | 0 (0/32) |
The number of positive eggs over the total number of eggs is indicated in parentheses.