Spring territories of 17 adult capercaillie (Tetrao urogallus L.) cocks were 10–79 ha in extent; they varied inversely in size with the relative proportion of mature forest within them. The number of resident cocks at leks increased with the amount of mature forest within a 1 km radius of each lek center. Leks in two areas (n=46) were regularly spaced with mean distances to nearest neighbors of 1.98 and 2.07 km, corresponding to the territorial space occupied by adult cocks of adjoining leks. In one area with intensive logging, interlek distance increased with decreasing amounts of mature forest between them. Spring home ranges of 18 adult females averaged 51.3 ha±8.2 SE. The spatial relationships did not fit recent models of interlek spacing based on female spacing behavior. Instead, the results suggested that spacing of leks may be related to the territorial requirements of males.