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Providing evidence to improve practice

Individual study: The effects of supplementary feeding on clutch size and egg weight of American coots Fulica americana nesting at Turnbull National Wildlife Refuge, Washington, USA

Published source details

Hill W.L. (1988) The effect of food abundance on the reproductive patterns of coots. The Condor, 90, 324-331


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 rails and coots to increase reproductive success Bird Conservation

A small randomised and controlled trial on a lake in Washington State, USA, in 1982 (Hill 1988), found that American coots Fulica americana from three territories given supplementary food (1 kg of dog food provided three times a week in each experimental territory) laid heavier eggs than coots from four control (unfed) territories (30 g/egg for fed birds vs. 28 g/egg for controls), but that there was no consistent effect on clutch size (first laid clutches: 8 eggs/clutch for fed territories vs. 9 eggs/clutch for controls; when including replacement clutched: 8.7 eggs/clutch vs. 9.0 eggs/clutch).