Gordon S. Warburton

Ruffed Grouse Survival and Population Structure in Western North Carolina

Sound management of ruffed grouse (Bonasa umbellus) populations requires an understanding of survival and cause-specific mortality; however, these parameters have not been investigated at the southern extent of the species' range. Ruffed grouse were studied in the mountains of western North Carolina. Grouse (n = 276) were radiotagged and monitored >3 times/week. Mean annual survival was greater than reports from the northern core of the species' range. Seasonal survival was greatest in summer, followed by fall, winter, and spring. Of 155 mortalities, the greatest proportion was...


Use of Spring Drumming Counts to Index Ruffed Grouse Populations in the Southern Appalachians

We studied ruffed grouse (Bonasa umbellus) drumming behavior in the southern Appalachian Mountains of North Carolina. We conducted drumming counts from late March through mid-April 2002-2004. Concurrent with drumming counts, radio-tagged males (N = 30) were monitored to determine proportion of males drumming. Drumming activity increased from late March (20% of males drumming) to a peak in mid-April (56%-69% of males drumming). Consistent drumming coincided with mean nest initiation date by females (12 April, N = 44). Drumming count results were related to fall trapping success on the study...


Drumming Log Habitat Selection by Male Ruffed Grouse in North Carolina

We evaluated ruffed grouse Bonasa umbellus drumming logs in western North Carolina to determine criteria used by male grouse in selecting drumming sites. For every drumming log found (N = 34), we selected a random log within the same stand type and with a similar topographic position. We collected data on drumming log characteristics and on vegetation surrounding the drumming site. We found 85% (N = 29) of drumming logs on or near a ridge top in a mature (>40 years old) oak/hickory (Quercus/Carya) or northern hardwood forest stand with a dense mid-story of mountain laurel (Kalmia...


Characteristics of Black Bear Mortality on the Coastal Plain of North Carolina

Black bear (Ursus americanus) mortality data were collected in eastern North Carolina from 1976 to 1992. These data included registered harvest totals from mandatory hunter-harvest records, field reports, and tooth samples from bears dying of all causes (N = 1,107 for harvest; N = 350 for vehicle-kill). Increasing trends in harvest corresponded to establishment of seasons in 11 counties beginning in 1986. Vehicle-kills increased until 1990 but declined during 1991-92. Combined age structures did not differ significantly from the 1976-1985 period (before new seasons established) to the 1986...


Movements of Black Bears on the Pisgah National Forest

Nineteen black bears (Ursus americanus) equipped with transmitter units were monitored on the Pisgah National Forest, North Carolina from May 1981-December 1982. Home ranges of males (61.0 km2) were 3.6 times greater than female home ranges (16.9 km2). Fall shuffles were not observed possibly due to the abundance and diversity of mast on the study area. Extensive overlap between reproductive females was observed, and the home ranges of adult males overlapped some female home ranges more than others. Dispersal of 2 subadult males occurred after they began using the same area as an adult...