Traditionality of Black Grouse Tetrao tetrix leks

Abstract

Many lek mating systems are characterized by traditional sites, which are used from year to year. We counted individual Black Grouse Tetrao tetrix on 6-171eks between 1987 and 1994 to study the traditionality of leks . We correlated male (adults and yearlings separately) and female numbers from each year against the corresponding figures of the previous year . There was a significant association in numbers of adult and yearling males both within and between successive years. Female counts were not correlated with past female or male numbers. Thus, it seems that the habit of young males to recruit preferentially to large leks, or to avoid the smallest leks, maintains the traditionality in Black Grouse leks .