Factors affecting habitat use by Appalachian ruffed grouse

A goal of many resource selection studies is to identify those habitats selected by a species. However, favorability of a particular habitat feature is likely contingent on such factors as landscape composition, predation risk, and an individual's resource needs. Thus, habitat selection may vary depending on context, and identifying causes of variability in habitat use could increase our understanding of functional aspects of a species' habitat ecology. Clear-cuts afford ruffed grouse (Bonasa umbellus) important escape cover, whereas access routes (roads and trails) and mesic bottomlands are viewed as important foraging areas for this species. We present a study of factors influencing strength of selection (i.e., use-availability) for these 3 habitat features by individual ruffed grouse. We analyzed radiotelemetry data from > 1,000 ruffed grouse monitored on 10 study sites in the central and southern Appalachians. Five sites were typified by mixed-mesophytic forests, and 5 were predominantly oak-hickory forests. Selection for clear-cuts was positively related to selection for access routes, but it was inversely related to selection for mesic bottomlands. Selection for mesic bottomlands and selection for access routes were positively related in oak-hickory forests, but they were unrelated in mixed-mesophytic forests. Clear-cuts were more strongly selected in mixed-mesophytic forests, and within each forest type, use of clear-cuts was strongest by adult males. Mesic bottomlands were only selected in oak-hickory forests, and within these forests they were most strongly selected by adult females. Following poor, hard-mast crops, use of access routes by female grouse increased. Use of clear-cuts and bottomlands increased for some or all sex and age classes of grouse following closure of hunting, suggesting that hunting discouraged use of these covers. Animals typically face a trade-off between survival and condition to maximize fitness, and our observations suggest that (relative to one another) male grouse favor refuging habitats whereas females favor foraging areas. At a landscape scale, grouse in areas having oak-hickory forests selected foraging habitats more strongly, whereas those inhabiting mixed-mesophytic forests made greater use of escape cover. Our findings indicate that habitat management prescriptions for Appalachian grouse can be tailored by forest type.