Citation. Korschgen, C. E.; Maxson, S. J.; Kuechle, V. B. 1984. Evaluation of implanted radio transmitters in ducks. Journal of Wildlife Management 48(3):982-987.   [1353  CC]

Abstract. Radiotelemetry has been used extensively to study free-ranging waterfowl by use of externally mounted radio packs (Patric et al. 1982). Although such mounts (Dwyer 1972) are suitable for man, species, they may cause weight loss, feather wear, and abnormal behavior (e.g., Greenwood and Sargeant 1973, Gilmer et al. 1974, Perry 1981). For some species, especially diving ducks, the problems caused by external mounts have outweighed the usefulness of the technique. Perry (1981) described abnormal behavior of canvasbacks (Aythya valisineria) fitted with back-mounted transmitters and discussed problems associated with disruption of insulating body feathers caused by the harness. Woakes and Butler (1975) observed that back-mounted transmitters interfered with normal diving behavior in tufted ducks (A. fuligula) and pochards (A. ferina). Transmitters attached to nasal saddles caused fewer problems than body-mounts (Perry;, 1981), but we question the advisability of using nasal mounts on diving ducks that obtain their principal foods by probing for benthic root stalks, tubers, and invertebrates. C. E. Korschgen (unpubl. data) and J. R. Serie (pers. commun.) found that wild canvasbacks released with nasal-mounted transmitters had enlarged nares and abraded and softened mandibles when recaptured. Also, nasal-mounted radios must be small, which greatly restricts the operating life of the transmitter. Researchers have successfully used intraperitoneal implants on certain fossorial (Smith and Whitney 1977) and semi-aquatic mammals (Melquist and Hornocker 1979, Melquist et al. 1981) and on many species of fish (Hart and Summerfelt l975, Warden and Lorio 1975, Johnsen and Hasler 1977). Abdominal implants have been used in physiological studies of birds (Southwick 1973, Woakes and Butler 1975). This report describes an evaluation conducted in 1982 of radio transmitters that were surgically implanted in the body cavity of captive and wild ducks. Our objectives were (1) to develop surgical procedures that could be used under field conditions to eventually implant radio transmitters in diving ducks and (2) to test the feasibility of using implanted radios in field studies.