Information on the survey of the three atlases of Finnish breeding birds and descriptive statistics of the distribution of 114 European bird species which have their northern range margin in southern Finland (southern spp.) and 34 boreal and Arctic bird species with their southernmost distributional margin in northern Finland (northern spp.).

<p>For each atlas, the total number of reports (N_rep) and the number of atlas cells surveyed (Cells) are given. A species' national range size was estimated as the number of atlas cells occupied (not corrected for differences in the coverage). ‘Latitude’ is the weighted mean latitude of a species' presence in each atlas, where weighting was based on the proportion of surveyed atlas cells per latitude which were occupied. Latitude is given in Finnish uniform grid coordinates, equivalent to kilometres north of the equator. Means are presented with their standard error.