著者

千羽 晋示

出版者

国立科学博物館

雑誌

自然教育園報告 (ISSN:0385759X)

巻号頁・発行日

vol.8, pp.121-134, 1978-02

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This report is the result obtained from a series of investigations on toads living in the National Park for Nature Study. I have not yet read the report by telemetry on investigations of moves by toads. Our efforts were undertaken by methods to confirm locations of toads. To pursue their moves, location telemetry was utilized. Our method was to place a transmitter on the back of toad, and we received by receiving apparatus (MM-BP type) produced by Meisei Electric firm. By this way, we confirmed locations, using flat board for survey. This method keeps high precision. As for the distance of 10 meters, maximum error might be I meter at most. Toads used had weight of 130 grams or more. Definitely they were adults. Transmitters had weight of 10-13 grams. Waves transmitted had 5 cycles. Investigation on five individuals at the same time was quite possible. However, in practice, interferences or jammings by hams, etc, were frequent. Consequently, investigation on two or three individuals was our inevitable limit. As for the entire result, examples of investigation are yet few. And definite figures are not yet gathered. However, roughly speaking, the following matters were clarified. As for toads, their particularly active zones of time are not yet ascertained. Comparatively speaking, encircling after sunset, midnight and before sunrise, their active time zones are likely to concentrate. The distance they move per day is fairly wide in individual difference, or by season, it seemed. But the maximum was 15-20 meters and the average was 15-20 meters. However, even the same toad differed in scope of move according to days. Or, sometimes similar tendency lasted. Interference by near-by toads has been considered nil. Anyhow, that point is not yet fully confirmed. Therefore, "home range" is regarded to exist. But it is difficult to form any positive assertion through the said recent investigation on the point.