Roosting Habitat of Merriam's Turkeys in the Black Hills, South Dakota

Lack of roost habitat (trees -40 cm diameter breast height [dbh] and _18 m2/ha basal area) can limit populations of Merriam's turkeys (Meleagris gallopavo merriami). The Black Hills region has relatively large populations of Merriam's turkeys, yet trees _40 cm dbh are uncommon. Consequently, I studied roosting habitat of this subspecies in a hierarchical manner to quantify roost habitat requirements in an area of apparent limited suitable roost habitat. Little or no selection for roosts occurred among macrohabitats. Basal area at roost sites averaged 19-25 m2/ha. Winter and summer (excluding hens with poult) roost sites were more similar than roost sites selected by hens with poults or random sites. Vegetative characteristics at roost plots showed trends toward trees with larger dbh, lower tree density (stems/ha), and higher basal area (m2/ ha). Roost trees averaged 35 cm dbh, but trees >23 cm dbh were used. Roost trees had layered horizontal branches and often large dbh, but large dbh was not a prerequisite for roost trees. Timber management practices in the Black Hills that modify the forest below 21 m2/ha and decrease the number of 25-35 cm dbh trees will reduce roosting habitat for Merriam's turkeys. J. WILDL. MANAGE. 56(4):750-759 Roosts are apparently important to sustaining populations of turkeys (Boeker and Scott 1969, Mackey 1984, Kilpatrick et al. 1988). Merriam's turkeys abandoned areas in Arizona where basal area at roost sites was reduced to 16.8 m2/ha (73 ft2/acre) (Scott and Boeker 1975). Bryant and Nish (1975) partially attributed nonuse of pinon-juniper (Pinus edulis-Juniperus spp.) habitats to the lack of suitable roost sites. Roost trees selected by Merriam's turkeys typically have been large (>40 cm dbh), mature, or overmature (large diameter old trees with flat tops and large horizontal branches) ponderosa pine (P. ponderosa) (Hoffman 1968, Boeker and Scott 1969, Phillips 1980). Narrowleaf cottonwood (Populus agustifolia), Engelmann spruce (Picea engelmannii), white fir (Abies concolor), and Douglas-fir (Pseudostuga menziesii) also are used for roosting (Hoffman 1968, Mackey 1984, Lutz and Crawford 1987). Trees >40 cm dbh are uncommon in the Black Hills, but the area supports large and sustaining turkey populations. My objective was to describe, in a hierarchical manner, the roosting habitat of Merriam's turkeys in an area where large (?40 cm dbh) trees were in short supply. This research was supported by the USDA Forest Service, Rocky Mountain Forest and Range Experiment Station; Black Hills National Forest; National Wild Turkey Federation; and South Dakota Game, Fish and Parks. Dr. A. J. Bjugstad (deceased) provided initial advice and encouragement. Technical assistance was provided by R. A. Hodorff, T. R. Mills, C. D. Oswald, K. J. Thorstenson, K. L. Jacobson, and L. J. Harris. M. P. Green volunteered his time throughout this study, and R. L. Taylor allowed access to his property. Appreciation is extended to W. C. Aney, J. G. Dickson, C. B. Edminster, R. W. Hoffman and 2 anonymous referees for review of manuscript drafts. STUDY AREA AND METHODS I conducted this study for 5 years (Mar 1986Jan 1991) in the central Black Hills of South Dakota. Elevation ranges from approximately 1,300 to 1,800 m above sea level. Most of the land was managed by the Black Hills National Forest, Pactola Ranger District. Private holdings associated with ranch operations occurred in some meadows and several private homes and cabins occurred within the study area. Vegetation of the study area was pure ponderosa pine forest (84%), with meadows and aspen (P. tremuloides)-birch (Betula papyrifera) vegetation in drainages. Some monotypic aspen stands occurred on northern exposures. Bur oak (Quercus macrocarpa) and white spruce (P. glauca) comprised <1% of the study area. Some turkeys in the Black Hills used ranch feed lots and suburban housing developments for winter feeding; others remained in the forest throughout winter or until deep snow forced them to use ranches (Petersen and Richardson 1975). My research was conducted on birds in the latter category. I trapped turkeys from late February to early March each year of the study using alpha-chlo750 This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain.