USE OF BREAKAWAY COTTON SPACERS ON RADIO COLLARS

Abstract

Fixed-diameter radio collars often are attached to large mammals for purposes of field research. Neck collars have created problems such as abrasions, cuts, and discomfort attributed to collar tightness (Servheen et al. 1981, Strathearn et al. 1984). Collars need to be fitted snugly to prevent premature removal, yet neck growth of young animals or seasonal increases in neck size occasionally lead to neck damage. Expandable collars and harnesses for transmitters have been developed for black bears (Ursus americanus) (Strathearn et al. 1984), bobcats (Felis rufus) (Jackson et al. 1985), and ungulates (Hamilton 1962, Kolz and Johnson 1980) to remedy this situation. We tried to minimize discomfort and neck injury to radio-collared black bears by using a breakaway spacer inserted between the ends of collars. This spacer was developed for radiocollared grizzly bears (Ursus arctos) in Montana (C. Servheen, Univ. Montana, pers. commun.). It was designed to tear apart from excessive pressure as the neck grew or from rotting over time. This paper reports on an assessment of these spacers and compares their effectiveness in 2 habitat types, the eastern deciduous forest of Shenandoah National Park, Virginia, and the Coastal Plain forested wetland in Great Dismal Swamp National Wildlife Refuge in Virginia and North Carolina.