Fig. 2.

The frequency of feeding visits (number per minute) by wood warbler parents to nests containing nestlings: a during the 3 min of presentation and b during the 20 min after an empty mount, mug and a taxidermy model of least weasel Mustela nivalis and Eurasian jay Garrulus glandarius were concealed. Shown are means (black squares) and standard errors (bars). In each treatment, the reaction of parent birds was tested at eight nests. The number of nests at which a feeding visit was recorded is given above the bars