‘Self-cleaning’ en broedsucces van een zwaar met olie besmeurde Kleine Mantelmeeuw Larus fuscus op Texel

incubating eggs on 24 May 2010. One particularly severely oiled individual (60% of body oiled) occupied a territory and incubated a 3-egg clutch within the main study plots of a large mixed gull colony on Texel. The nest was marked in anticipation of a breeding failure. When the eggs hatched, however, the oiled bird was colour-ringed (green ring, code M.AMZ) to monitor its possible recovery and breeding success. Self-cleaning was time-consuming, but successful within a period of four weeks (nearly completely clean; some specks of oil in the wing and neck remaining). The progress of self-cleaning was documented with digital photos and a log (Table 1), while for each of 25 feather fields the amount of contamination was scored on a six-point scale (0-clean, 5= black and shiny; Table 2) Meanwhile, the affected bird successfully shared the incubation of a 3-egg clutch and produced fish boluses during handling (indicating foraging activities at sea). The eggs hatched and at least one chick fledged successfully with a growth rate that was not different from the overall colony mean. The chick was marked with a green ring, code K.ACN.