22CY Black-headed Gull White LYD – 20180128
Category Archives: Black-headed Gull
Chroicocephalus ridibundus
Primary covert variation in 1st-winter Black-headed Gulls
Reading ringed gulls in Leiden – 20171204
Reading ringed gulls in Leiden and Katwijk – 20171117
Black-headed Gull White ECM9 displaying courtship and territorial behaviour – 20170304
Return of the Black-headed Gull with an extra ‘foot’ – 20161211
Celebrating my 200th ringed Black-headed Gull and 1600 sightings in Leiden
1CY Black-headed Gull with an extra ‘foot’ – 20151226
1CY Black-headed Gull White EFJ5 – 20150625
Group effort: ring reading during sand suppletion activities at Scheveningen – 2015
