Removal and replacement of male blue grouse on persistent and transient territorial sites

Publisher Website
Google Scholar
Abstract
In the springs of 1978 and 1979 we removed all male blue grouse (Dendragapus obscurus), both original occupants and subsequent replacements, from a series of persistent and transient territorial sites (those used regularly and intermittently, respectively). In both years more replacements settled on persistent than on transient sites. Most replacement males were adults, most of which likely would not have taken territories had we not made these sites available. The presence of nonterritorial adults, reported here for the first time, suggests that territorial behaviour limits breeding densities of male blue grouse. Testes of replacement adults, although smaller than those of resident males collected at comparable times, all contained mature sperm. Yearling males are seldom territorial; but of eight that took territories on removal sites all except one selected persistent sites.