Intraclutch variation in egg size of American coots


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for rails and coots to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for rails and coots to increase reproductive success

    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.


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