Characteristics of Persistent and Transient Territorial Sites of Male Blue Grouse

Abstract

Male blue grouse (Dendragapus obscurus) are promiscuous and territorial, with territories serving as areas where males can display and breed without interference from other males (Bendell and Elliott 1967). Intensive studies on Vancouver Island, British Columbia, demonstrated that areas used by males for territories had unequal frequencies of use (Lewis 1979). Some were used regularly, others intermittently. Sites used at least 9 of the 10 years studied (1969-78) were called persistent, those used 8 years or less (Lewis 1979). Although the term persistent implies use in every year, sites occupied for 9 years were included in this category because of the chance that the site actually was used in the year it was recorded as vacant, even though the presence of a male was undetected by the field techniques used. Experimental evidence indicates that males prefer persistent sites for territories (Lewis and Zwickel 1980), and males using these sites had significantly more females near them in early spring and survived significantly longer than those using transient sites (Lewis 1979). Here I examine physical and vegetative characteristics of a series of persistent and transient territorial sites to identify those features that may be important in their selection by blue grouse.