Albert de Jong
Larus cachinnans hybrid 2CY, 5CY & 7CY 4P60 June 2005 UK, September 2008 Lithuania, January 2010 Austria.
Hybrid Caspian x Herring Gull, green 4P60. Bird ringed as pullus on May 09 2004 at Wisla Wloclawek Tama, Poland. Bird from a mixed colony. Mother known as Caspian, father as Herring Gull. Ringed as a chick in the Wloclawek colony, Poland, May 09 2004. In many ways this bird shows classic intermediacy. Its bill is easily within the range of Caspian, but in adult plumage it has a Herring Gull-like pale eye and P10 pattern (more black than white). Its legs are yellow-toned, but this is of no real consequence.
below: 2CY 4P60 June 05 2005, Cambridge, UK. Picture: Dick Newell.
Bird in active complete moult, P7-P10 still old.
below: 5CY 4P60 September 10 2008, Dumpiai dump Klaipeda Caly Obszar, Lithuania. Picture: Hannu Koskinen & Visa Rauste.
Bird in active complete moult, P7 fully grown, P10 still old. Active moult in central greater coverts and outermost secondaries. Note plain grey greater primary coverts as indication for adult plumage. Pale yellow iris, streaking all over the head, darker mask around the eye indicate hybrid. White tongue on P10 not square ended, instead tappering as in many argentatus.
below: a real Caspian Gull for comparison, photographed the same day, same location.
below: 7CY 4P60 January 18 2010, Wörth, Austria. Picture: Wolfgang Schweighofer.
Full band on P5. Much black on bill and in general more compact-looking than other Caspians present.