The “Trace Recorder”, a new device for surveying mammal home ranges, and its application to raccoon dog research

Abstract

A new telemetric system known as the “Trace Recorder” was developed in order to reduce labor costs and to avoid radio-tracking location errors. It was first tested during studies of habitat utilization by raccoon dog, Nyctereutes procyonoides viverrinus, in Japan. The Trace Recorder (TR) consists of four separate units : beacons, recording units (RU), an automatic collar release system (ACRS) and a personal computer for processing data. The beacons emit 8 kHz magnetic signals periodically. A total of 600 different magnetic codes can be used in order to identify locations. The collar-based RU intercepts and records signals when the study animal is within 3 m of a beacon. The ACRS installed on the collar alongside the RU allows the collar to be released by a special code and recovered so as to facilitate the retrieval of stored data. In order of evaluate the capabilities of the trace recorder system, we used the TR in the analysis of the habitat use of a raccoon dog for 25 days between 16 November and 10 December 1996 in Hinode Town, suburb of Tokyo. Twenty-four beacons were set at along paths, at a garbage site, and at badger setts and animal latrines. The RU recorded 91 time units and durations of visits to trails and to some cores sites were collected. The TR system is capable of recording census data 24 hours every day for three months. The new TR system proved to be more accurate than current radio-telemetry equipment for recording frequency, duration and times of visits to target sites by the study animal.