Nest site characteristics and cuckoo-host egg phenotype contrasts at marsh warbler nests naturally parasitised by the common cuckoo and the nearest unparasitised nests.

Data are presented as Means ± SD (ranges). Spot cover and spot distribution are expressed as proportions (see also Material and Methods). Test statistic refers to paired t-tests or Wilcoxon's rank sum tests (indicated as V in brackets), depending on the distribution of the variables. Background and spot color color contrasts as well as luminance contrasts are calculated based on the Vorobyev & Osorio's (1998) perceptual model and the units are JND, meaning “just noticeable differences”. Degrees of freedom are 20 in some cases because for one pair of clutches we did not measure some of the variables.