Nest building in titmice Paridae: Selectivity in bryophyte use

In many bird species, reproductive success is dependent on nest quality. However, detailed data on nest composition are scarce, and quantitative analyses have generally used only rough categories, without species identification. Bryophytes dominate the nests of many passerine bird species, but little is known about whether birds have preferences for certain species. In this study, we determined the bryophyte species composition in nests of blue tits Cyanistes caeruleus and great tits Parus major in a forest near Oslo, Norway. We also sampled the abundance of the bryophyte species in plots on the forest floor surrounding a subset of the great tit nests. Blue tits and great tits both used 15 bryophyte species as nest materials, mainly the same pleurocarpous species but in different proportions. The tits preferred highly branched bryophyte species, i.e. Pleurozium schreberi, Rhytidiadelphus squarrosus and Sanionia uncinata, but avoided common forest-floor bryophyte species that are sparsel..., The data was collected in a forest nearby Oslo SE Norway and consists of two main types of data (but with derived files): bryophyte species composition of 69 nests of blue- and great tit and data on the bryophyte species composition, sampled in 167 plots, surrounding nine trees with nest boxes. Where the bryophyte species composition of these nests was recorded in two different years. For further details, please read the readme files and the published paper., All files are txt-files and can be opened in most softwares.