An improved radiocollar for eastern cottontail rabbits

Premature loss of radiomarkers is a problem in many telemetry studies. We d escribe and report retention rates for 4 radiocollar designs used on easter n cottontail rabbits (Sylvilagus floridanus), January 1997 to January 1999, at Black Prairie Wildlife Management Area, Mississippi. These 4 designs ar e modifications of a collar developed by Advanced Telemetry Systems, Inc., and include a nylon collar with a single fastener (NSF), nylon collar with a double fastener (NDF), neoprene collar with a double fastener (NPDF), and modified neoprene collar with a double fastener (MNPDF). We estimated 90-d ay retention rates in a failure-time context to evaluate collar loss. Reten tion rate differed among collar designs (P<0.001) and was influenced by col lar material (P<0.001) but not number of fasteners (P>0.05). Neoprene colla rs had greater 90-day retention rates (NPDF=86.15%, MNPDF=100.0%) than nylo n collars (NSF=29.4%, NDF=25.5%). Reasons for collar loss were chewed, slip ped, fastener pulled through collar, or collar-related mortality and injury . We recommend the MNPDF as the best design because of the high retention r ate and well-positioned antenna.