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Providing evidence to improve practice

Individual study: The effect of food supplementation on egg volume of Eurasian oystercatchers Haematopus ostralegus breeding on Schiermonnikoog, Friesland, the Netherlands

Published source details

Jager T.D., Hulscher J.B. & Kersten M. (2000) Egg size, egg composition and reproductive success in the oystercatcher Haematopus ostralegus. Ibis, 142, 603-613


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide supplementary food for waders to increase reproductive success Bird Conservation

A small controlled trial on a saltmarsh on the island of Schiermonnikoog, The Netherlands (Jager et al. 2000) found that seven female Eurasian oystercatchers Haematopus ostralegus, following the experimental removal of their first clutch, did not produce significantly larger eggs (as part of a replacement clutch) if provided with 50 boiled mussels Mytilus edulis (averaging 46 mm long) a day, compared with control (unfed) oystercatchers (average egg volume of 41.2 cm3 for fed females, n = 7 vs. 43.4 cm3 for control females, n = 19). In addition, the replacement eggs of fed females were, on average, smaller than original eggs (by 0.9 cm3), whereas replacement eggs for control females were larger than originals (by 0.2 cm3).