Black-headed Gull Chroicocephalus ridibundus

(last update: 30-05-2011)

Black-headed Gull x Mediterranean Gull

Sightings of this type of hybrids are documented in Belgium, France, The Netherlands, United Kingdom, Czech Republic and Norway.

Characteristics of an adult female hybrid, recorded in Molsbroek nature reserve (2011):

• Hood: shape as Black-Headed Gull (extending less far on hind neck), colouration as Mediterranean Gull (black with pronounced white eye-crescents).
• Bill: less strong and darker as Mediterranean Gull
• Wing: upperwing grey, outer primaries white triangle (P10-P7) with small black subterminal spots on P9-P6. Underwing without characteristic dark area of Black-headed Gull on mid to inner hand.

Second-generation hybridization is observed in France: successful breeding pair of male hybrid x female Black-headed Gull (Leray et al, 1999) and in Belgium: failed breeding attempt of female hybrid x male Black-headed Gull (Audenaert et al. in prep).

References
Leray V., Yésou P., Beaudoin J.-C., Fossé A., (1999). Un hybride Mouette rieuse x Mouette mélanocéphale a élevé deux jeunes en Maine-et-Loire en 1998. Ornithos 6: 40-45.

Audenaert T., De Smet G., Kearsley L., Van Lembergen E., (in prep.). Observations on a failed breeding pair of a female hybrid Black-headed Gull x Mediterranean Gull and male Black-headed Gull in Molsbroek Nature reserve (Belgium).

Poprach K., Haluzik M. & Chytil J., (2007) Breeding biology, biometry and ethology of the Mediterranean Gull (Larus melanocephalus) in the Czech Republic. Sylvia 43: 88–108.