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Providing evidence to improve practice

Individual study: Impact of supplementary feeding on within-clutch variation in egg size in American coot Fulica americana at Minnedosa, Manitoba, Canada

Published source details

Arnold T.W. (1991) Intraclutch variation in egg size of American coots. The Condor, 93, 19-27


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 randomised, replicated and controlled study in wetlands in Manitoba, Canada, in 1987-9 (Arnold 1991), found that within-clutch variation in the size of American coot Fulica americana eggs was slightly (and significantly) lower in territories where supplementary food was provided (at least one of steam- rolled corn, commercial trout food, commercial rabbit, chicken layer diet or oystershell), compared to in control (unfed) territories (3,219 eggs from 357 clutches measured, standard deviation of 1.2 cm3 for fed clutches vs. 1.4 cm3 for controls). Additional results from this study are presented in Arnold 1994.