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Providing evidence to improve practice

Individual study: Effects of the provision of supplementary calcium on pied flycatchers Ficedula hypoleuca breeding in an area of pine forest near Kilingi-Nõmme, Pa'rnu, Estonia

Published source details

Mänd R. & Tilgar V. (2003) Does supplementary calcium reduce the cost of reproduction in the pied flycatcher Ficedula hypoleuca? Ibis, 145, 67-77


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

Provide calcium supplements to increase survival or reproductive success Bird Conservation

A replicated, controlled trial in a pine forest site in Estonia in 1995-7 and 1999 (Mänd & Tilgar 2003) found that pied flycatchers Ficedula hypoleuca provided with supplementary calcium laid larger eggs and their chicks were larger, compared to control (unsupplemented) birds (average size of 1.63 cm3 for 172 supplemented clutches vs. 159 cm3 for 178 controls; average leg length of 17.3 mm for 81 supplemented chicks vs. 17.2 mm for 89 controls). In addition, supplemented female flycatchers laying seven or more eggs were significantly heavier than controls. There were no differences in laying date, clutch size, number of fledglings or chick weights between treatments. Calcium was provided in the form of small snail shell and eggshell fragments in a feeder within the nest boxes. Control nest boxes had empty feeders in. A subset of the data from this study is discussed in (6).