著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.2, no.2, pp.53-54, 1963

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.2, no.1, pp.17-22, 1961

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An imperfect body with a complete skull of <I>Crocidura dsinezumi orii</I> Kuroda 1924, was found in a stomach of <I>Trimeresurus okinavensis</I>, which was colleced in July, 1960 by Mr. T. Morita and Dr. K. Koba at Yuwandake, Amami-Oshima, Japan. It is the second and unique specimen of <I>orii</I>, because this form has only been known by a type, a skin and an imperfect skull, collected in 1922 and destroyed by fire in 1945. The second specimen, adult male, is easily distinguished from <I>russula, sodyi, tanakae, thornasi, dsinezumi, umbrina, chisai, shantungensis, watasei</I> and <I>tadae</I> by relatively longer fur of the back (6.0-6.5 mm against 2.5×5.0 mm), decidedly larger claws of manus (2.7 mm against 1.1-1.8 mm), much shorter braincase (nearly circular against oblong), and posteriorly located posterior border of anteorbital foramen and anterior extremity of orbit. Therefore, this form may not be a subspecies of <I>dsinezumi</I> but a distinct species, <I>Crocidura orii</I>, peculiar to the small island.

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.5, no.6, pp.213-223, 1973

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The newly proposed method of taxonomic analysis employing the binomial distribution seems to be usefull to clarify the presence of the reproductive isolation among the members of a population from a continuous region. The binomial distribution is always observed in a local population composed of individuals belonging to a single biological species, but not in a false population containing two or more such species. The reason is briefly explained in the following lines.<BR>In a true local population, variation of a morphological character under the influence of several genes generally shows the normal distribution, so that an allelomorphic type refered to the left or the right half of the distribution always appears at the rate of one half. Therefore, all possible combinations of such allelomorphic types of several qualified characters may occur in the population. Each of the qualified characters here used is composed of two allelomorphic types which have an appearance ratio of one to one, and are not correlated to the other characters and independent with sex, age, season, etc.<BR>If the allelomorphic types of each of the qualified characters are expressed by a capital and a small letters, A a, B b, etc., variations in the number of capital letters in each individual of the true population always constitute a binomial distribution following the laws of combination and probability. But, such binomial distribution cannot occur in a false population composed of two or more distinct species, for the individuals are segregated by the reproductive isolation and random distributions of allelomorphic types are greatly disturbed.<BR>Close correlations between the nature of population and the binomial distribution were confirmed in a true population of <I>Clethriononiys bedfordiae</I> from the main island of Hokkaido and in a false population composed of <I>C. sikotanensis</I> and <I>C. rex</I> from Rishiri Island, off Hokkaido.

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.4, no.2, pp.35-39, 1968

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Two species of <I>Nyctalus</I>, the large noctule <I>N. lasiopterus aviator</I> THOMAS, 1911 and the lesser noctule <I>N. noctula motoyoshii</I> KURODA, 1934 (=<I>Nyctalus noctula</I> NAMIE, 1889), have been known from Japan. The former is common everywhere, but the latter seems to be rare and is known only by two missing syntypes studied by Namie. The author recently had an opportunity to examine several specimens of a kind of smaller noctule obtained from Japan, which were remarkably different from <I>motoyoshii</I> and much similar to the typical <I>noctula</I>. This raised a doubt about the taxonomic status of <I>motoyoshii</I>. Then, the original description and the figures of this species were carefully examined and several characters differing from the genus <I>Nyctalus</I> were found out by the author. On the other hand, all the characters of <I>motoyoshii</I> mentioned in the original description well agree with <I>Vespertilio</I> from Japan. Therefore, <I>motoyoshii</I> seems to be nothing but a synonym of <I>Vespertilio superans</I> which is rather common to the type locality of the former, Chichibu, central Japan.

著者

今泉 吉典 吉行 瑞子

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.2, no.4, pp.105-108, 1965

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A specimen, subadult female, of <I>Tadarida</I> was collected from Kumamoto City, Kyushu, Japan, by Dr. H. Tange in April, 1964. It is identified as <I>T. insignis</I> (BLYTH, 1861) and hence the third record for this species in Japan. If this identification is correct, <I>insignis</I> may not be a subspecies of <I>T. teniotis</I> but a distinct species differing in the following characters; 1) the wing membranes are only inserted to the lower third of the tibia instead of just above the ankle; 2) calcar with a distinct keel; 3) color of fur is fuscous, much darker than that of <I>teniotis</I>; 4) in the skull, zygomatic and lachrymal breadth are relatively narrower and the mandible is relatively longer than in <I>teniotis</I>; 5) lower incisors are strongly imbricated and the relatively larger second incisor extends to the middle of the inner lobe of the first incisor. The distribution of <I>insignis</I> is confined to China, Korea, southern Ussuri and Japan and clearly separated from that of <I>teniotis</I> by a broad region extending from Indo China and Tibet to Afghanistan.

著者

今泉 吉典 吉行 瑞子 土屋 公幸

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.3, no.2, pp.44-45, 1966

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.2, no.5, pp.131-135, 1965

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The so-called Fissura palatina of <I>Equus</I>, broadly used in the veterinary anatomy, is undoubtedly homologous with the Foramen incisivum of <I>Homo sapiens</I>. The latter seems to be derived from the pared incisive foramina of the lower Primates by reduction of the size of the incisive foramina and reduction of the palatine processes between the foramina and the Fissura palatina of <I>Equus</I> by an enormous development of the processes. Therefore the Fissura palatina of <I>Equus</I> must be strictly called Foramen incisivum. On the other hand, the so-called Foramen incisivum of <I>Equus</I> is a quite different structure and has no concern with the same named foramen of human anatomy. Therefore, the author wants to designate such a foramen between the medial border of the palatal portion of the premaxillaries as Foramen intermaxillare. Such a small foramen is not infrequently found in <I>Mogera, Microtus, Rattus</I>, and etc. An enormous foramen, posterior to Foramen incisivum, found in Ursidae-and some Mustelidae, is also considered to be Foramen intermaxillare, because it is bordered completely by the palatal process of the premaxillaries.

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.6, no.3, pp.127-136, 1975

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<I>Lutronectes whiteleyi</I> GRAY, 1867, based on two young specimens collected from Hakodate, Hokkaido, Japan, seems to be extinct in the native land, and no specimens have been known in Japan.<BR>While studying the river otter of Japan, the author was attracted his attention by an adult rough skeleton of the subgenus <I>Lutra</I> in the mammal collection of the National Science Museum, Tokyo. Unfortunately the locality of the specimen is uncertain, but there is little doubt that it was collected at the beginning of the Mei ji era, nearly 100 years ago, in the territory of Japan at that time, that is Hondo or Hokkaido. As the specimen is evidently different from the otter of Hondo, the locality is inevitably estimated as Hokkaido.<BR>This estimation coincides with the result of identification of the specimen as <I>Lutra whiteleyi</I> based on strong similarities to OGNEV's adult specimen from Nemuro, Hokkaido, and dissimilarities to the most of the named forms of the subgenus <I>Lutra</I>, in several cranial measurements.<BR>If this identification is correct, <I>whiteleyi</I> seems to be a well established taxon of <I>Lutra lutra</I> group characterized by relatively narrow mastoid breadth and shorter muzzle (Table 6, F and G) .<BR>An opinion that <I>whiteleyi</I> covers whole populations of the Japanese otter, proposed by Pococx (1931), the present author (1949), etc., is not correct. <I>L. whiteleyi</I> must be confined to the Hokkaido population.

著者

今泉 吉典 吉行 瑞子 小原 巖 土屋 公幸 今泉 忠明

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.4, no.3, pp.63-73, 1969

被引用文献数

1

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Three distinct mammal communities were recognized in a forest region on the western slope of Mt. Fuji, Honshu, Japan. Among them, the subalpine conifer forest community is relatively poor both in the number of species and in the density of populations of small mammals and is distinguished from the subalpine deciduous forest community by the absence of <I>Apodemus speciosus speciosus</I> and rarity of <I>Eothenomys kageus</I>. The low mountain mixed forest community is characterized by the presence of <I>Urotrichus talpoides hondonis</I> and the absence of <I>Dymecodon pilirostris</I>.<BR>In the most of species found in this region, the habitat range seems to clearly correlate with the nature of forests. However, those of <I>Dymecodon</I> and <I>Urotrichus</I> are exception and seem to be mainly determined by a kind of competition between them.<BR>In the region above Shôjiguchi Ni-gôme, 1, 500-2, 380 m alt., the habitat range of <I>Dymecodon</I> was completely confined to an area above and that of <I>Urotrichus</I> mostly to an area below a line at about 1, 600 m alt. in a mixed forest. However, two specimens of <I>Urotrichus</I> were obtained in the habitat range of <I>Dymecodon</I>, one at 2, 380 m and the other at 1, 670 m alt. This indicates that the habitat ranges of these two species are mostly segregated, but the territory of <I>Dymecodon</I> population is not so exclusive as that of <I>Urotrichus</I> and contains several individuals of the latter. Quite same phenomena of such special segregation between these two species have been known from Mt. Hayachine, Tohoku District, and Mt. Yatsugatake, Central Honshu.<BR>This can be explained clearly by a following hypothesis. There is a "competition by power" between those two shrew-mole species which are nearly related and similar in general habits including the ecological niche but are slightly different in size and physical strength. So that the individuals of the stronger species, <I>Urotrichus</I>, able to successfully maintain their territories against the individuals of the weaker one, <I>Dymecodon</I>, but the reverse is not true. If the population density of the stronger species is nearly in saturation in an area, then the individuals of the weaker species may be completely driven out from there. But, the stronger species probably able to invade rather freely into the range of weaker species and to live on there.<BR>It is probable that <I>Dymecodon</I>, evidently more primitive and older in origin than <I>Urotrichus</I>, had probably covered nearly completely the foot of Mt. Fuji in ancient times. After that <I>Urotrichus</I> had arrived there and gradually drove out <I>Dymecodon</I> from the foot to subalpine region. However in some regions where <I>Urotrichus</I> perhaps had failed to invade by some kinds of barriers, populations of <I>Dymecodon</I> have been maintained well to the present day. A population of <I>Dymecodon</I> at Lake Motosu region, 910m alt., may be such living remnant.

著者

高田 靖司

出版者

日本哺乳類学会

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.10, no.3, pp.123-134, 1985-02-28 (Released:2010-08-25)

参考文献数

19

被引用文献数

1

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愛知県三河湾の佐久島 (171ha) と本土 (春日井市・名古屋市) の間で、野生ハツカネズミの分布と密度 (捕獲率を尺度とする) を比較した。1981年から1984年までの調査により次の事がわかった。1) 島には本種の他に, ドブネズミとジネズミが見られ, その他の野生哺乳類を欠く。2) 本土では本種の他に, アカネズミ, カヤネズミ, ハタネズミ, ジネズミ及びヒミズが見られる。3) 島のハツカネズミは森林を除いて、調べた総ての生息環境, すなわちイネ科の一年生と多年生の草地, タバコ・クワ畑及びヨシ湿地に独占して見られる。4) 本土のハツカネズミはイネ科の一年生草地にだけ優占し, ここでも他のネズミと共存している.また, 多年生草地と森林にはアカネズミが, ヨシ湿地にはカヤネズミが優占している。5) 本土の各生息環境におけるネズミ類の総密度は, 島の同じ生息環境におけるそれに等しいか, あるいはより高い.6) 他の優占的な競争種を欠く島におけるハツカネズミの密度, 繁殖, 齢構造及び食性は生息環境間で異なることが示唆された。ハツカネズミの生息地拡大と好みの分析から, その分布を決定する上で重要な要因として, 1) ネズミ共同体, 特にアカネズミやカヤネズミのような優占的な競争者, 2) 環境, 特に植生に働く人為作用が考えられた。

著者

古屋 義男

出版者

日本哺乳類学会

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.7, no.1, pp.39-43, 1976-11-30 (Released:2010-08-25)

参考文献数

4

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The otters (presumed as Amblonyx cinerea) were observed nineteen times during the period from November 1974 to February 1975 in Padas bay, Sabah, Malaysia. All of these nineteen observations were done in daytime and at eleven out of them they formed a group consisting of 4 to 8 otters. And thier food habit, vocal sounds and other behaviors that we observed are reported.

著者

古屋 義男

出版者

日本哺乳類学会

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.5, no.6, pp.199-205, 1973-07-30 (Released:2010-08-25)

参考文献数

4

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When was the masked palm civet (Paguma larvata) introduced into Japan and how has its habitat been extended? These problems have so far been discussed but no definite conclusion has been reached yet.The writer sent out questionaries to the game rangers in Shizuoka Prefecture asking them whether the animal lives or not in the area under their charge. Their answers seem to indicate that its habitat extends from four source areas. Therefore it is supposed that the civet was imported several times into several areas in the Prefecture from several places of origin.

著者

今泉 吉典

出版者

THE MAMMAL SOCIETY OF JAPAN

雑誌

哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)

巻号頁・発行日

vol.4, no.4, pp.102-106, 1969

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オオシマアカネズミの標本95点を調査した結果,次のことが判明した。(1)夏毛と冬毛は背毛では刺毛の有無により,腹毛では色彩によってほぼ判定することができる。(2)更毛は年2回,4・5月と10・11月に行なわれる。(3)腹毛には夏毛・冬毛ともほぼ2つの色型があり,冬毛よりも夏毛の方が明らかに濃色である。(4)腹毛の色彩は夏毛・冬毛とも♂ よりも♀のほうが濃色の傾向が強い。