Rapid advances in the field of electronics over the past several years have made powerful research tools available to pinniped investigators. In particular, the remarkable miniaturization of solid-state circuitry through semiconductor technology has made it feasible to deploy highly sophisticated instruments on free-ranging individuals. These instruments have become important assets in the study of pinniped behaviour, ecology and physiology.
This chapter briefly outlines some of the types of instruments that have relevance to studies of free-ranging Antarctic seals. No attempt has been made to include a description of instruments and devices principally used in captive or laboratory studies. The main categories of instruments described are radio tracking and telemetry, sonic devices, archival recorders (behavioural, ecological and physiological) and satellite-linked hardware. A section on attachment methods is also included. A list of the addresses of research groups or manufacturers is provided in Appendix 5.1, at the end of this chapter.
Radio tracking and telemetry
Radio transmitters have been utilized in wildlife studies since the early 1960s (Cochran & Lord, 1963), and have assisted research on Antarctic pinnipeds since 1968 (Siniff, Tester & Kuechle, 1969, 1971). Transmitters can be monitored for two basic types of information: (1) the presence or absence of a signal (e.g. haul-out patterns, location) and (2) the relay of various types of data (e.g. heart rate, ambient temperature). Most studies using radio transmitters attached to Antarctic seals have involved monitoring activity patterns and movements of individuals (e.g. Siniff J.L. Bengtson et al., 1975). In addition to the brief description given below, several other sources offer a helpful introduction to using radio transmitters in wildlife studies (Cochran, 1980; Amlaner & Macdonald, 1980;Cheeseman & Mitson, 1982; Kenward, 1987).