Several collar materials (nylon webbing, nylon-covered rubber tubing, nylon webbing lined with nutria fur, boltaron hard plastic, latex tubing, and a nylon harness) and 2 transmitter weights (60 and 120 g) were comparatively tested for potential use as radio transmitter units for nutria (Myocastor coypus). Most collar materials caused dermatitis, abrasions, or lesion around the neck and the animals continuously worked their way out of the nylon harness. The only combination which did not cause any adverse physiological reaction was the nylon-covered rubber tubing collar with a 60 g dummy transmitter. The tubing collars were attached with a tightness approximately 14% greater than neck circumference; this expansion allowed normal feeding and grooming yet prevented the animals from getting their front paws caught between the collar and neck.
