Mean Size Of Females Research Articles

During spring 1970, locations of 10 male and 3 female ruffed grouse (Bonasa umbellus) were determined with an automatic radio-tracking system on the Cedar Creek Natural History Area in east-central Minnesota. Mean weekly range size of drumming adult males was significantly greater than that of drumming juvenile males. An inverse relationship was found between mean weekly range size of males and their level of drumming activity. Mean range size of females increased in an approximately linear manner during the six weeks prior to incubation but became much smaller (ca. 2 ha) during incubation. Cumulative ranges of drumming males were more fixed in space than, and approximately half as large as, those of females. Male ranges became more fixed in space after the onset of the drumming season. Cumulative ranges of drumming males contained centrally located core areas (anti x = 2.26 ha) of intensive use and consistent occupancy over time. Habitat quality and neighboring males are probably the two major factors influencing spring space use of drumming males.