Reproductive behavior of the Japanese dipper, Cinclus pallasii studied in spring, 1978 in Hakone National Park, Japan, and the American dipper, Cinclus mexicanus, studied in spring 1977 in the Sierra Nevadafoothills, California, are described and their mating systems examined. Similarities between the two species were as follows. 1) Both species were living in an area frequented by man, and in fact built their nests in man-made walls that formed dams. 2) Both species showed rigid territoriality, and rarely crossed the boundaries of their territories. Males and females engaged in territorial defense by means of the territorial defense flight. 3) The sequence of events during the reproductive season varied from what is usually seen in birds in that the pair bond was formed before courtship displays were performed. 4) The male of both species switched mates during the nest building phase. Both the old and new mate were later present together in the nest area when courtship and/or copulation took place, and in the case of C. mexicanus, the male copulated with both females. 5) Females showed partial asynchrony in reproductive cycles in adjoining territories. Differences were also observed. 1) Nests were situated in adjoining territories so that they occurred closer together for C. pallasii than for C. mexicanus. 2) C. pallasii showed a greater tendancy to fly over land rather than to follow the course of the stream as C. mexicanus did. 3) The courtship display performed by C. mexicanus was what I called the vertical stretch display, while a horizontal stretch display was performed by C. pallasii. Both species performed the circular display flight. I hypothesize that the striking similarities in reproductive behavior of C. mexicanus and C. pallasii are due largely to the similarities of the environment in this study, especially the effects man has on their habitat. The presence of man and his influences on the habitat through the building of dams, bridges, and fish hatcheries, works to limit or clump resources critical to the nesting behaviors of C. mexicanus and C. pallasii, especially nesting sites and feeding areas. This factor, along with the preadaptations of the two species of dippers for polygyny, through unequal parental care, the use of closed nests, allowing for less parental care, asynchrony in the reproductive cycles of females, and utilization of an aquatic food supply, allows these species to adopt a polygynous mating system. Inversely, since dippers are so well adapted to a polygynous mating system, they are able to cope with changes in their environment brought on by man.
The urban avifauna in the breeding season was studied in Obihiro City containing 150, 000 population from late May through mid-July of 1977 and 1980. Censuses were carried out by a strip census method using the road in four different habitats, namely the wood dominated by Quercus dentata, new and old residental areas with rich vegetation, and residental area with poor vegetation. During the study period each plot was censused 18 times, the total distance of transect censused being 23.4 to 27km in four plots. These distance of transects were sufficient to list up the common bird species occurred in each plot, since the total number of species observed stopped to increase at 11 to 24km of total distance. The number of bird species observed decreased as the proportion of area with vegetation cover decreased, 39 in the wood (plot A), 33 in the new residental area (plot B), 23 in the old residental area (plot C) and 9 in the central part of the city with poor vegetation (plot D). In the plot A dominant bird species were Emberiza spodocephala, Sitta europaea, Dendrocopos major, Passer rutilans, Parus palustris, Parus major and so on. Many of the species recorded there were known to prefer wooded habitats and they comprised 90% of the total number of individuals. Passer montanus was the most abundant in three residental areas. Other dominant species in urban habitats included Emberiza spodocephala, Sturnus cineraceus, Carduelis sinica and Anthus hodgsoni in the plot B, C. sinica, Motacilla alba and Corvus corone in the plot C, and Columba livia var. domestica and M. alba in the plot D. In the plot B, however, a few forest and grassland birds were fairly common because of presence of woodlot and open area covered with grasses. The species which were fairly abundant in the urban habitats were Passer montanus, Columba livia var. domestica, Carduelis sinica and Motacilla alba, and they comprised 53 to 99% of total number of individuals there. Of them first two species were the birds typically associated with the urban environment. The species diversity (H') reduced as the vegetation cover reduced, being the highest in the wood and the lowest in the residental area with poor vegetation. The index of similarity was high between the avifauna in plot C and that in plot D, and low between the avifauna in plot C and that in other urban habitats.
A study of the urban and suburban avifauna in the breeding season was conducted in relation to vegetation cover in Obihiro, Hokkaido, from 1976 to 1978. From the central part of the city to agricultural lands, 157 study plots (500×500m2) were established. Vegetation cover included parks, yards, shrines, cultivated fields, grasslands, shelter belts, woodlots in agricultural land, vacant lots, river beds and so on and was classified generously into two groups: wooded area and grassland. The percentage of vegetation cover on each plot was calculated on the basis of air photographs and a map of wooded area of Obihiro. Each plot was censused once at least by a strip census method from late May to early July, the total distance of transect censused being 278.7km. In addition to these, only bird species observed were recorded twice at least on each plot. Common species in plots in which vegetation cover was less then 10% were Passer montanus, Motacilla alba, Carduelis sinica, Corvus corone and Columba livia var. domestica. In addition to these species, the regularly occuring species increased as the percentage of vegetation cover increased: they included Emberiza spodocephala, Sturnus cineraceus, Cuculus canorus, Saxicola torquata and Acrocephalus bistrigiceps in the plots with 11 to 20% of vegetation cover, Gallinago hardwickii, Alauda arvensis and Lanius bucephalus in the plots with 21 to 60% of vegetation cover, and Dendrocopos major, Anthus hodgsoni, Erithacus calliope, Parus major and Uragus sibiricus in the plots where vegetation cover was more than 60%. The species which prefer wooded area occurred mainly in the higher percentage of vegetation cover. Thus the number of bird species observed increased as the percentage of vegetation cover increased, although the increase in the number of bird species was inconsiderable in the higher percentage of vegetation cover. The relationship between the number of bird species (y) and percentage of vegetation cover (x) is y=4.1744+0.3542x-0.0020x2. Paralleling the trend in changing number of species, bird species diversity (H') increased from A (wooded area is less than 10%) through B (wooded area is 11-20%) to C (wooded area is more than 20%). The increase in diversity was found with increase in the percentage of grassland within A group. The similar trend was found in B and C groups, respectively. Bird species diversity was the highest in habitats having both woodlots and grassland.
The observations of occurrence of Pterodroma externa cervicalis were carried out in the west area of North Pacific Ocean during the several cruises by R. V. Hakuho Maru as follows: KH 74-2 (30 April to 26 June, 1974), KH 74-4 (6 November to 7 December, 1974), KH 75-3 (14 May to 2 June, 1975), KH 80-2 (25 April to 18 June, 1980), KH 80-3 (14 July to 6 September, 1980), and KH 80-4 (24 September to 13 October, 1980). 1) P. externa cervicalis did not appear in the area of 30°N and northward in May and June, but this bird was found in the same area late in July. In August, the flocks of P, externa cervicalis (individual number of 2 to 15) associated with several species of tropical and subtropical sea birds, wedge-tailed shearwater Puffinus pacificus, sooty tern Sterna fuscata, white noddy Anous albus and common noddy Anous stolidus, occurred frequently in the east of Mariana Islands and they attacked the fish schools on water surface. And the flyings of solitary or two individuals of this bird scattered widely in the west area of North Pacific Ocean between 25°N and 35°N from September through November. 2) P. externa cervicalis occurred in the area where the water temperature of sea surface ranged from 20.7°C to 31.4°C, and especially this bird distributed abundantly in the area between 27°C and 30°C. 3) From those observations, it is concluded that some considerable number of P. externa cervicalis migrated regularly to the west area of North Pacific Ocean during the period from July through November.
1. In April 1974, a schizochroismic or buff-mutant Corvus macrorhynchos was observed among a group of young birds in the Imperial Palace garden. Three years later in 1977, possibly the same bird, presumed to be a male, occurred, with his 'normal' mate, in the territory of "A pair", to usurp its nesting tree, which was in my garden, about 1.5km from the Imperial Palace. 2.This would indicate that young crows may pass 3-4 years before first breeding. 3. The "buff pair" continued territorial quarrels between "A" and "D" pairs and occupied their territory between them. But, the territorial boundary changed through the season and by year, especially between that of "A pair". 4. Thus, the "buff pair" might haven't succeed to raise their young, although their possible nest was found and nest-site selection behavior was observed, during their territorial life of four years until 1981, when the buff-mutant male disappeared (Observations in years 1979-'80 were insufficient). 5. In years 1969-'70, the "A pair" had a territory size as large as 45ha, but lost more than 3/4 area in 1977, by invasion of "buff pair", maintaining only about 10ha. 6. This small territorial size of about 10ha is, however, about the same as or even larger than grouped territories at Roppongi. 7. In this area a pair raised two young safely in one of the trees in a small territory of about 6ha within a parking area surrounded by buildings. 8. The city condition with small houses (and only few large buildings) and good distant sight, and that with many high buildings and restricted sight, were compared with open country and forest conditions respectively. 9. In small house or open cities, the communication between members of a pair or finding of intruding rivals, is possible at long distances and human garbages, which are main food source for city crows, are scattered by small amounts. Under such conditions, the crows would hold a large territory. 10. In high-building cities, the mutual or rival sight is restricted to short ranges and large amount of garbages from buildings are collected at certain places. Therefore, a small territory is advantageous for defense and enough food supply can be obtained within it. 11. The "A pair" territory in 1969-'70 at Akasaka of 45ha is considered to have been a maximum territory size under "small-house city" condition, while, by the time when the "buff pair" invaded into it in 1977, many large buildings had been constructed and this area was already a "high building city". This may have made the "buff pair" succeed to invade deep into "A pair's" territory, which was oppressed to almost 1/4 (about 10ha) of the original size. However, this probably the minimum territory size (about 8-10ha) was found to be common and stable in "high-building" area at Roppongi. 12. It would follow that if only an enough food supply (human garbage) could be available, the crows may inhabit "high-building" area in fairly high density maintaining small territories. 13. But, if building garbage were more perfectly managed (not allowing the use by crows), crows would rely on natural foods of parks or garden area, showing patchy distribution and occupying large territory. 14. In a large territory of "small-house city" zone, that included some wooded hills and gardens where some natural food was available beside human garbage, three chicks were raised (as in Akasaka, 1967-'70), but in small territories of "high-building" area, where human garbage only is the food source, the brood size may be limited to two chicks, as observed in two cases in Rappongi area.
The purpose of this paper is to clarify the cause of death and emaciation of Puffinus tenuirostris that occur along the Pacific coast of Japan. The pathological, hematological and parasitological investigations were applied on 34 dead and sacrificed Puffinus tenuirostris which were mainly collected in Johga-shima area of Japan in the period from May to June, 1978. Gross lesions seen at necropsy were the atrophy and cloudy swelling of skeletal muscle and atrophy of subcutaneous adipose tissues (19/34). All the birds were considered to be very young from the histological findings of testis, ovary, bursa fabricius and other organs. Histopathologically, the following findings were obtained. The degeneration of skeletal muscle (21/31), hemosiderosis of liver (16/31) and kidney (7/26), atrophy of spleen (14/17), hyaline droplet degeneration of renal tubule (9/26), colloidal degeneration of bone-marrow (1/1), and degeneration of myocardium (10/32). Hematologically, severe anemia (2/10), and polychromasia and hypochromia of erythrocytes were seen (4/10). In the investigation of parasite, severe parasitism of Ixodoidea belonging to Procellariphahaga longithororacica (Piaget, 1880) and Halipeurus abonorimis (Piaget, 1885), and Cestoda of Tetrabothrius scoogi (Nybelin, 1916) were observed. However, malaria-like protozoa were not found. In summary, the investigation of the present cases revealed that no findings of infectious disease were seen, and anemia and malnutrition were thought to be the cause of death in very young bird.