Habitat use by spruce grouse in northern Wisconsin

Abstract

Spruce grouse (Falcipennis canadensis) habitat use varies widely across their range and is not well-understood near the southern extent of their range. Threats to conifers from climate change make understanding habitat use at the southern edge of the range increasingly important. We obtained habitat information on 55 radiocollared spruce grouse in northern Wisconsin, USA from 16 May 2007 to 10 July 2012. Black spruce (Picea mariana) and tamarack (Larix laricina) were the most common habitat components. Some of our findings differed from previous reports, including little use of eastern hemlock (Tsuga canadensis) or northern white cedar (Thuja occidentalis), use of tamarack in summer more than any other tree species, and winter roosting and feeding in red pine (Pinus resinosa), especially where jack pine (P. banksiana) was not available. Male display points contained fewer small broadleaf saplings (x¯ = 652 trees/ha), greater percent conifer (87%), more jack pine (x¯ = 148 trees/ha), and denser canopy (x¯ = 65% closure) compared with random points (3,288 small broadleaf saplings/ha, 70% conifer, 7 jack pine/ha, and 51% closure). Dense ground cover was the best predictor of brood points, although brood points were similar to random points. Winter flock points were typified by dense canopy cover (x¯ = 76% closure) and more jack pine (x¯ = 407/ha). Management should be focused on areas with extensive conifer, especially near black spruce–tamarack swamps. Retaining or establishing closed-canopy coniferous uplands, especially jack pine stands 15–30 years old, adjacent to lowland conifer swamps should benefit spruce grouse populations. © 2013 The Wildlife Society.