1976〜2004年の4月下旬〜6月下旬(高標高地では7月下旬)に北海道中部・南東部の642区画(5km×5km),調査路725か所でルリビタキの生息状況を調べた.このうちルリビタキが出現したのは,それぞれ71区画(11%),81か所(11%)であった.生息環境別の出現率はハイマツ林で92%,常緑針葉樹林で54%,針広混交林で37%,落葉広葉樹林で10%,カラマツ人工林で4%で,農耕地や住宅地では0%であった.ルリビタキは東部では標高50m以上,それ以外の地域では標高250m前後以上に生息しており,出現率は標高601〜800m以上で高くなった.調査路2kmあたりの観察個体数(平均値±SD)は,ハイマツ林では2.5±2.4羽,常緑針葉樹林では0.4±1.0羽,針広混交林で0.3±0.6羽,落葉広葉樹林で0.1±0.4羽,カラマツ林で0羽で,生息環境によって違いがみられた.また出現率は温量指数の低いほど高くなった.

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The red-bellied tree squirrel, Callosciurus erythraeus, (common name : Formosan squirrel) has been introduced as a pet and naturalized in the suburban forests of Kanagawa Prefecture since the 1950 s. The study was conducted in 5.3 ha area in the forest of Yokohama Nature Sanctuary including various types of vegetation. Of 50 nests observed in the study area, conifer plantation and broad-leaved evergreen forests were preferentially used as nest sites. We collected 13 nests in May 2002 and 12 nests in January 2003, and the nest materials were examined. In outer layer of nests, the numerous twigs with leaves were used and included the tree species that the nest was established, such as, Castanopsis cuspidata, Quercus myrsinaefolia, and Chamaecyparis obtusa. Inner barks of conifer trees were most frequently used as inner nest materials. Mostly in winter, the middle layer made with large leaves (Q. serrata, Aucuba japonica) and outer barks of conifer trees were observed. The conifer plantation in suburban environments was important habitat for the alien squirrels in respect of nest sites and nest materials.

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I collected 7 individual of Sorex minutissimus hawkeri in the wetland of in Kiritappu Hamanaka-cho and in the sand area Kenbokuki Island. The capture record in Kenbokki is since S. m. hawkeri was already caught in Hichirippi, Hamanaka in 1985. S. m. hawkeri was captured until now was Wetland and a forest, this time they were caught in the sand area for the first time. The captures of this species were also recorded in Kunashiri, and Etorofu islands near Hokkaido. However the capture was no record in such a small island as Kenbokuki Island. S. m. hawkeri was observed eating beach fleas in a cage.

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Sorex minutissimus hawkeri of 9 individuals was caught in August, 2004 and September, 2004 on Kenbokki Island of Hokkaido. Nine individuals were caught, and among those, five individuals were alive and were caught. S.m. hawkeri was caught in the range from the position of 5 m to 15 m from the coastline. S.m. hawkeri made space between grass and was resting there. S.m. hawkeri rose and fell frequently to the grass upper part. Moreover, S.m. hawkeri might not move for tens of seconds to several minutes, where it is the grass upper part and the head is hung down downward.

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北海道のエゾヤチネズミの生息数の年変動は,春から秋にかけての繁殖期に生息数が増加し,秋から翌春までの非繁殖期に生息数が減少するというパターンがみられる.記号放逐法により月齢のコホートの生命表を作製し,それを基に各コホートの生存率,出生率を求めた.ある時点における各コホートの月齢組成ベクトルは生存率と出生率から成るレスリー行列をとおしてつぎの時点の月齢組成ベクトルに射影される.これらの連続した各時点の月齢組成を比較検討することによって年変動のパターンの経過を考察した.齢組成ベクトルの時系列が生息数の増減過程を検討する上で,非常に有効であることが示された.次篇では大発生(100匹以上)とみなされる生息数が繁殖期間の長さ・出生率のわずかな差によってもたらされることをシミュレイトにより検証し,レスリー行列による各時点の月齢構成が個体数の増加・減退を知る目安としても役立つことを示す.

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Skylark, Alauda arvensis, is known as one of the most popular birds in palearctic grassland and farmland in North Asia and Europe. A decrease of the European race, Alauda arvensis arvensis, has been pointed out, which is possibly responsible to the recent decrease and deterioration of farmland. A decrease of the Japanese race, Alauda arvensis japonica, has also been pointed out. To establish the conservation ecology of the species, it is vital to clarify the ecological and habitat characteristics. There have, however, been little ecological and habitat characterizations of the present Japanese race. The author investigated its breeding status in grassland islanded by surrounding forests in Tokyo District. It was confirmed that, as a habitat suitable for breeding and feeding, a grassland must not only involve suitable vegetation, but also be situated with limited distance from the surrounding forest.

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A bat survey was carried out July and September 2003 and August 2004, in Shihoro River and Osarushinai River, in the central part of Tokachi, Hokkaido. Seven species of bats were caught in mist nets : Myotis daubentonii, Myotis ikonnikovi, Myotis frater, Epitesicus nilssonii, Vespertilio superans, Plecotus auritus and Murina ussuriensis. Among seven species, five species seemed to breed in this area, as suggested by the capture of lactating or post-lactating females (M. daubentonii, Epitesicus nilssonii and P. auritus) and/or the capture of yearlings (V. superans, P. auritus and M ussuriensis).

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Myotis daubentonii (Chiroptera) was first recorded from Sapporo, Ishikari and Tobetsu, Hokkaido in 2005, as the new westmost records in Hokkaido. During the survey we captured a young individual, which was born early this year and still nursed. Therefore, it is highly probable that the species breeds in the area around the Ishikari River. This species possibly uses hollow trees as its breeding sites around the study areas

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In field investigation of mammals, it is usually very difficult to obtain precise habitat information. To identify field mammals precisely I tried to use animal hair examination methods. Three observation methods were compared, that of the cuticular scales by SUMP method, that of the medulla structure by the prepared slide method, and that of the outer morphology under stereo-microscope. Twenty small-sized mammal species which belong to Insectivora, Chiroptela, Lagomorpha and Rodentia, were supplied as experimental materials. Result indicated that classification of the samples into the four Orders is easily made. Also it was possible to identify families in some orders. Specific identification within the same genus was not easy, but it would be possibile if more adequate data are available.

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Insects inhabiting on a riverbed suffer erosion by running water and flooding, thus sopposed to assume ecological characteristics of species inhabiting unstable environment. Polyphylla laticollis, a scarabaeid beetle, is an example of such species, found in the middle riparian galleries of the River Tama since early 1980's, but its biology has not been well-known. Investigation was carried out to estimate population size, using mark and recapture method, at three sites involved in two cities, Inagi and Tama. The population peak, as estimated by mark-release method, was the end of July, after which the population decreased. The numbers and sex ratio of adults captured by light traps at three survey sites differed considerably. Their flight began at around 19 : 00 and ceased at around 4:00 in July, with the peak at around 21:00-22:00. The time period of flight activity of males was earlier than that of females. The results suggest that large and small-size populations are distributed patchily along the river sides.

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Evolution is one of the important points of view for biological studies, but most of the biologists studying ecology of recent living organisms know little about extinct species. In this paper, I introduce Japanese fossil birds of the Cenzoic era, excluding Preistocene and Holocene. The Japanese Islands were separated from the Chinese Continent, and surrounded by the sea since Cenzoic era, and many fossil seabirds, including some largest species, have been dug out from Cenzoic strata in Japan. A penguin-like Pericaniformes, copepteryx, was found in Japan, one of which species was the largest Plotopterigidae of the world, and another one of which was one of the most completely preserved fossil specimens. Also unique Pelecaniformes, Pelagornithidae, had tooth-like bony structure and wings of 5-6 m long wing span. They have been found widely and from Oligocene to Pliocene and are thought to be important in considering evolution of Pelagornithidae. In addition, there were scores of fossil birds that were extinct, and they have close relationship with recent birds found in Japan. It is reasonable to suggest that Japan is one of the most important places in which many fossil birds were found for studies on evolution and biogeography of birds

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