Overall impression of Caspian Gull but see ringing data below.
Species: Larus cachinnans / argentatus (born in the nest of pair: cachinnans female x hybrid argentatus/cachinnans male; both parents known and trapped during 2006 season; thus 46P1 shall be a backcross hybrid (second generation hybrid),despite looking quite like pure cach.
Date: 17.05.2006
Age: pullus (from egg B, laid on 19 April, hatched 16 or 17.05.06)
Place: Wloclawek, Vistula river, Kujawsko-Pomorskie province, Poland, 52:39N, 19:08E
Ringer: Grzegorz Neubauer