Territorial behavior of beaver (Castor canadensis) has not been well documented in the Southeast. Study of this behavioral mechanism may lead to methods which may aid in the control of nuisance beavers in economic and environmentally sensitive areas. Territorial behavior was evaluated for beaver in 4 study areas in the Piedmont of South Carolina by monitoring scent marking and movements of adjacent colonies. Scent marking was observed during January 1982 to June 1985 on 1 area with high (≥ 0.8 beavers/ha) and 3 areas with low densities (≤0.3/ ha), of beaver. Beaver (N = 9) from 2 adjacent colonies were implanted intraperitoneally with radio transmitters and monitored from February 1983 through March 1984. Beaver on the high-density area built and maintained scent mounds from mid-September through mid-June. Beavers built new mounds from mid- September to late December. Scent mound relative visitation frequencies peaked at 55% per week during October and November, declined to 35% in December and 25% in January and February. Scent mounds were observed on only 1 of 3 low-density areas. These mounds appeared during October or November and were usually visited only when constructed. Interactions between 2 adjacent colonies were highest in fall and winter and were close to a common boundary delineated by scent mounds, indicating a scent-fence function. Higher levels of intra-colony interaction caused by competition for woody forage during fall and winter may be responsible for increased scent marking activities during this period.
