HABITAT USE BY SPRUCE GROUSE IN A FRAGMENTED SYSTEM

The spruce grouse is a boreal obligate species that has been protected in Michigan since 1915 (Ammann 1963). Despite protection, the status of spruce grouse is uncertain in Michigan and other parts of the Midwest, and there have been few attempts at large-scale surveys or monitoring (Williamson et al. 2008). I studied a population of spruce grouse near the southern edge of their range on the Yellow Dog Plains in Marquette County, Michigan. I investigated fecal pellet counts as a possible method to assess spruce grouse presence and habitat use. My results validated the use of fecal pellet occurrence as an indicator to habitat use. I used these data to determine which habitat patches were used by spruce grouse. Structure and composition of habitat used by spruce grouse were described on the Yellow Dog Plains at the levels of forest patch, and point of presence. I used vegetation cover and composition metrics, as well as measures of patch connectivity, size and complexity to predict presence of spruce grouse. Patch level habitat use by spruce grouse on the Yellow Dog Plains was greatly influenced by patch area and canopy density (Canonical Correlation2=0.36, df=2, P\u3c0.001) I analyzed historical aerial photography of the Yellow Dog Plains in Marquette County, Michigan, from 1937 to 2011 to determine how land cover change influenced spruce grouse habitat. To predict the likely effect of these changes, I created an index to habitat quality (a combination of patch size, and canopy coverage). Based upon these results, the Yellow Dog Plains has become increasingly fragmented and high quality spruce grouse habitat has decreased and is being replaced by intermediate quality habitat