HOOGERWERF A (1975) Short announcements: About double clutches of the Oystercatcher Haematopus ostralegus. LIMOSA 48 (1): 116-116.

Eurasian Oystercatcher Haematopus ostralegus When visiting the Wadden island Ameland in 1967, on 27 May a clutch of 6 eggs was found of the Oystercatcher, Haematopus ostralegus and again at about the same locality on 24 May 1968 (see LIMOSA 41: 113-115). On 5 June 1974 such a clutch was found on the Wadden island Vlieland and two days later, at quite a different locality, one containing 5 eggs. Because the normal clutch contains 3 eggs it is almost certain that two female birds deposited their eggs in the same nest in all four cases, although the presence of 3 birds was established at one occasion only (in 1968).

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