Nestedness was examined for vascular plants and birds in the centres and edges of 26 sites of ancient oak-hazel woodland in Sweden. Both taxa exhibited significant nestedness in site centres and for whole sites, but not at the edges for birds. Woodland ranks of nestedness differed between plants and birds. Rank of nestedness of birds, but not of plants, depended on area. Horizontal habitat structure affected nestedness of both plants and birds. Mobility appears decisive for creating rank differences between sites for various taxa. High mobility may also explain a greater edge effect in birds from allochtonous, more or less transient individuals. Nestedness in relation to mobility, particularly at edges, should be of theoretical interest. The possible use of nestedness patterns in conservation makes further analyses urgent for less mobile taxa.