著者
阿部 学
出版者
日本鳥学会
雑誌
(ISSN:00409480)
巻号頁・発行日
vol.24, no.97, pp.P57-60, 1975-12
著者
阿部 学 北原 英治
出版者
森林総合研究所
雑誌
森林総合研究所研究報告 (ISSN:09164405)
巻号頁・発行日
no.356, pp.p29-45, 1989-12

新たに開発したヘリコプターセンサス法を用いて,群馬県の国有林2297haにおいてカモシカ等のセンサスを行った。1982~1984年の各々3月に実施したセンサスで,105個体,134個体,119個体のカモシカを数え,三者間に有意差はなかった。また,同調査地内の1314haで二日間にわたって行った再現性のテストでも,各々48個体,43個体を数え,互いに有意差はなく,当調査法の再現性の高いことが判明した。区画法との比較を行った結果,316haの中で地上では2.37~2.96個体/km2を,空からは5.7個体/km2を数え,空からの調査は地上調査の約2倍となった。三か年間の調査でカモシカをはじめノウサギ,ツキノワグマ,イヌワシ,ヤマドリなど13種の鳥獣が識別できた。ノウサギとヤマドリはカモシカと並行してセンサスを行い,各々74個体,54個体を数えた。この結果,当調査法はカモシカのみならず他の鳥獣への適用の可能性を示唆した。ヘリコプターセンサスの利点は,1)地形,植生,積雪などの地上条件に左右されない,2)動物に動きを与えるので発見が容易である,3)地上調査に比べて広範囲の調査が可能で,小面積調査に由来する誤差が小さい,4)再現性が高い,5)非積雪地帯でも適用可能で汎用性が高い,6)同時に複数の鳥獣のセンサスが可能,などである。
著者
阿部 学
出版者
ニュ-・サイエンス社
雑誌
動物と自然 (ISSN:03864782)
巻号頁・発行日
vol.15, no.9, pp.p12-16, 1985-08
被引用文献数
1
著者
富田 克利 上野 孝幸 河野 元治 三浦 英樹 北村 良介 大場 孝信
出版者
日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.42, no.3, 2003-03-28

第38次南極地域観測隊(1996-1997)によって採取されたリーセルラルセン山地域の地表から140cmの深さまでの試料について,粘土鉱物学的研究を行った.本研究では,粘土鉱物の種類や性質について,垂直的な変化や,風化の違いによる平面的な変化があるかを考察した.
著者
Yokohata Yasushi Ikeda Yukio Yokota Masatsugu Ishizaki Hideharu
出版者
「野生生物と社会」学会
雑誌
Biosphere conservation : for nature, wildlife, and humans (ISSN:13446797)
巻号頁・発行日
vol.5, no.1, pp.39-46, 2003-03
被引用文献数
1

The ecosystem of Uotsuri-jima, one of the islands in the Senkaku Archipelago, off southwestern Japan, has probably been devastated by a dramatic increase in goats (Capra aegarus) since their deliberate introduction in 1978. Because the Senkaku Islands are claimed as national territory by China, Taiwan, and Japan, scientific researchers have been unable to land on Uotsuri-jima, nor have there been opportunities to eradicate the goats there. The effects of the goats on the vegetation of the island were assessed therefore using remote-sensing techniques : aerial photographs, Landsat satellite images, and an IKONOS satellite image. The results showed that bare patches have emerged in several areas, and that particular floral communities on the raised coral reefs may have already been lost. Since the flora of the sub-canopy layers are not visible beneath the dense forest canopy that covers most of the island, using current remote-sensing methods, very little is known about the extent of damage to the flora of these layers. Land-based surveys are thus urgently required to assess the condition of the flora and to control the introduced goats.
著者
犬飼 哲夫 門崎 允昭
出版者
日本応用動物昆虫学会
雑誌
日本応用動物昆虫学会誌 (ISSN:00214914)
巻号頁・発行日
vol.18, no.3, pp.139-144, 1974-09-25
被引用文献数
1 4

The age of Ursus arctos yesoensis was known to be determined by teeth annuli, but the number and clarity of annuli sometimes differed from bear to bear or between the different kinds of teeth obtained from the same individual. In order to examine the characteristics of teeth annuli, 2 bears of known age (No.5 and 7) and 6 bears of unknown age were employed. The age of the bears of unknown was estimated by examining J_1 and P_4 teeth, which exhibited clear annuli. The teeth of J_1,J_2,J_3,C, P_1,P_4,M_1,M_2 and M_3 of the lower jaw obtained from No. 7 bear and some others were analyzed for detecting morphological and numerical differences of annuli. The age estimated from the annuli of C was sometimes younger than the actual age by one year due probably to the delayed development of the canine. The annuli numbers observed in the other kind of teeth coincided with one another (Fig. 9-17). There were 2 assertions that in the first one, the annuli formed in the period before the hibernation, and that in another, it begun to form in the fall and completed in April or May of the next year. In No. 1 (11 years and 8 months) bear which was killed at the end of September, J_1 showed 11 annuli in the inner part of the cementum, and the marginal cement layer was unstained. However, a little stained short line was found in it, indicating a new annulus formation (Fig. 1). P_4 of No. 2 (3y. & 9m.) bear which was killed in early October showed almost the same feature of new annulus formation as that of No.1 (Fig. 2). J-1 of No. 3 (14y. & 10m.) bear which was killed at the end of November had 15 annuli, of which the outmost one was stained faintly (Fig. 3). J_1 of No. 4 (2y. & 10m.) bear which was killed at the end of November showed about the same features as that of J_1 of No. 3 (Fig. 4). P_4 of No. 5 (5y. & 1m.) bear which was killed in the middle of Feburuary had 5 distinct annuli, and the outmost annulus was clear and perfect (Fig. 5). J_1 of No. 6 (11y. & 2m.) bear which was killed at the end of March had 11 clear annuli, and an unstained cementum layer was developing on the outer side of the outmost annulus (Fig. 6). P_ 4 of No. 7 (5y. & 3m.) bear which was killed in the middle of April showed 5 dark stained annuli, and an unstained cementum layer developed in some extent (Fig. 7). J_1 of No. 8 (10y. & 4m.) bear which was killed at the beginning of May showed 10 annuli with a well developed marginal unstained cementum layer (Fig. 8). It was clear that the formation of new annulus began in the middle of September and continued up to the end of April. The No. 5 bear was castrated male , so that it was suggested that the sex hormone had no relation to the annuli formation (Fig. 24). In this species the so-called accessory lines appeared, which closely resembled annuli and were also reported in grazzly bear. Therefore, in such a case, several kinds of teeth should be examined for an exact age determination. The mechanism of the accessory line formation and its significance are not known at present.
著者
青木 文一郎
出版者
社団法人日本動物学会
雑誌
動物学雑誌 (ISSN:00445118)
巻号頁・発行日
vol.22, no.257, pp.221-225, 1910-03-15