- Whitcomb, Scott Douglas
The Graduate School, University of Maine
I studied patch occupancy, fall dispersal and the population characteristics of spruce grouse (Dendragapus canadensis) in fragmented habitat on the southeaster edge of their range. I identified 36 insular patches of potential habitat that varied in size and were widely distributed on Mount Desert Island (MDI), Maine. I systematically surveyed each habitat patch during April-May 1992-1993 to determine patch occupancy and estimate population sizes. Female spruce grouse(n=18) and juveniles (n=9) were equipped with radio transmitters and monitored from nesting through fall dispersal.
Spruce grouse on MDI are confined to a few small patches of lowland conifer habitat which are at risk of local extinction. Successful dispersal among habitat patches is therefore important to the longer persistence of the island's population. Although dispersers moved great enough distances to reach habitat patches, only 2 to 9 moved to a different patch. Additionally, production on MDI was lower than previously reported. Several factors including productivity, patch occupancy, and dispersal probably combine to regulate the spruce grouse population on MDI.