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Individual study: Supplemental food provision has little effect on final nestling weight, tarsus length, growth rate, or survival of house wren Troglodytes aedon, the Mackinaw Study Area, Illinois, USA

Published source details

Styrsky J.D., Dobbs R.C. & Thompson C.F. (2000) Food-supplementation does not override the effect of egg mass on fitness-related traits of nestling house wrens. Journal of Animal Ecology, 69, 690-702

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Provide supplementary food for songbirds to increase reproductive success Bird Conservation

A randomised, replicated and controlled trial in a forest in Illinois, USA, in 1998 (Styrsky et al. 2000), found that ‘early-season’ house wren Troglodytes aedon nestlings (i.e. from clutches laid in mid-May) in nest boxes provided with supplementary food were significantly heavier than nestlings from early-season control broods (fed nestlings approximately 2% heavier than controls, 62 tested). There was no difference in weight between fed and control late-season (laid in late June to early July) broods (53 tested). There were no differences between treatments for tarsus lengths, growth rates or survival until fledgling for either early or late season broods. Food consisted of 30 g of mealworms Tenebrio molitor supplied each day within the nest boxes.