Scent marking by Alaskan moose: characteristics and spatial distribution of rubbed trees

Abstract

We studied scent marking (rubbing of trees) in Alaskan moose (Alces alces gigas) in interior Alaska during 1989. Pole-sized trees were stripped of bark and rubbed by adult female and adult male moose; marking by females occurred during the peak of rut (late September – early October) when most females were in estrus, whereas marking by males was in late rut (mid-October – November). Moose selected white spruce (Picea glauca) as well as trees with particular physical characteristics for marking. The tops of 18.5% of 54 trees marked by moose were dead, whereas only 0.5% of 201 trees available for marking had dead tops. The distribution of scent-marked trees on rutting grounds was not spatially clumped. We hypothesize that rubbing of trees by females advertises their estrus, and that rubbing by males late in rut serves to attract females not successfully bred early in rut and may help prime estrus in these females.