The bird communities of subalpine coniferous forest in Shiga-Kogen, central Japan were studied in nine breeding seasons from 1973 to 1981 and were compared with some bird communities of several subalpine coniferous and temperate deciduous forests. The census data were analyzed in relation to three parts, which are: coniferous part, deciduous part and the ecotone between the above two parts. The characteristic feature for the bird communities of subalpine coniferous forest is the extremely high and stable population densities of a few species. In the coniferous part, four species showed the high and stable population densities. These birds are Parus ater, Regulus regulus, Phylloscopus borealis and Tarsiger cyanurus. At lower fringe of subalpine coniferous forest, the bird community showed: high number of species, high bird density, high diversity index and low dominance index. These phenomena are due to invaded species from deciduous forest, such as Parus major, Ficedula narcissina and Erithacus cyane, and existence of ecotone preferring edge species, such as Emberiza variabilis and Phylloscopus tenellipes. Excepting Parus ater, remaining main three species of coniferous part suddenly disappear through ecotone in the deciduous part. For analysis of the structure of bird community, the concept of adaptive space (Nakamura 1978•1980) was applied. About 70% out of overall population density of bird community in coniferous part consisted of main three groups of adaptive spaces, that are the titmice, warbler and thrush types. Especially, the adaptive space of warbler type, which includes two high density species, Regulus regulus and Phylloscopus borealis, has the largest volume of adaptive space in the subalpine coniferous forest studied.
Annual variation of breeding woodland bird communities was investigated at several plots for 4-12 years by territory mapping method. In young planted forests, number of territories increased or decreased in many species, showing certain trends, but the total number of territories in each plot increased year after year. However, the composition of dominant species-group did not change during the study period at each plot, except immediately after planting. In mature or natural forests, relatively few species showed trends of increase or decrease of territory numbers. The territory number fluctuated irregularly in each species, but this fluctuation did not exceed the twofold of annual mean. Coefficient of variance (C=σ/m) of total number of territories at each plot remained at more or less 10%. Breeding bird densities were affected variously by deforestation or weeding. Similarity indices of bird communities (Whittaker 1952) of each study area were calculated, and similarity dendrograms were composed. Annual data of bird communites at each study area were compared by χ2 homogeneity tests. Except for casual effects of deforesting or weeding, the structure of bird community in temperate zone forests would not change significantly within a period of about ten years, and the climax forest would persist unchanged for much longer period.
A survey on population density and habitat of the Tree Sparrow (Passer montanus) in a winter season was carried out at 18 areas in Hokkaido from November 1976 to March 1977. Results of this survey were compared with those in a breeding season. Population density was very much different in each surveyed area. The highest density was 1280.0/km2, which the lowest one was winter season reached 2.1 times of the one in the breeding season, but this winter season density was 0.4 times of the breeding season in the rural areas. This fact suggests migration of adult birds from urban to rural area in spring and vice versa in autumn. The correlation between population density and number of houses was conspicuous in the winter season (r=0.7537>r0.05). Furthermore, population density of the Tree Sparrow correlated with human population (r=0.6479>r0.05). Home range of the Tree Sparrow was restricted to the area near the house. In the urban area, 98.2% of their activity was seen with 20m of the house, and such percentage reached to 99.5% in the rural area. In urban area, they fed most commonly in the house (23.8%), but in the dump yard in rural area (53.3%).
Ecological segregation between Alpine and Japanese Accentors, Prunella collaris and P. rubida, was analysed by the relative abundance in several types of environments and the comparisons of foraging sites and song posts. This study was conducted in the alpine zone of Mt. Kisokoma, Central Honshu during April, 1977 and October, 1980. Results obtained were as follows: (1) P. collaris occurred principally on bare gounds (gravel field 30.3%, rock field 25.6%) and P. rubida in alpine shrubbery (58.3%). (2) In alpine shrubbery, P. collaris was observed on tree trunks or on the forest floor, while P. rubida was found on twigs to branches for the most part, the two species dividing the lower and upper strata of the forest. (3) The foraging sites differed by the two species; P. collaris took food mainly on gravel field (46.2%), and alpine grassland (25.2%), while P. rubida worked in alpine shrubbery (57.3%). (4) Both species used surface of remaining snow foraging place, on which insects are drifted by upward air current from the foot zone and they ligered on the snow as long as it persisted on the slope. (5) P. collaris selected as high as 68.2% of song posts on rocky slope, while 87.4% of song posts of P. rubida was in the alpine shrubbery.
An ecological survey of Cyanopica cyana was conducted from 1976 to 1980 in Hikage, Kinasa district (west part), Kamiminochi County, Nagano Prefecture. In this village it is resident through the year, even in winter with 1-1.5m of snowfall from December to April. Its maximum flock size ranged from 40-45 birds. Six nests were found within an area of 4km×0.3-0.8km and two were found 3.5km from the flock home range (non-breeding season wandering area). It nested in fir, Japanese cedar, Kaizukaibuki and Japanese apricot, and eggs were laid between early June and mid July, the clutch size being 6-7 and in three nests 1-2 eggs were left unhatched. One nest was parasitized by Cuckoo (Cuculus canorus). The Cuckoo chick, though it pushed out the Blue Magpie's eggs and a chick, starved because parent Blue Magpies abandoned the nest. Kenji Kobayashi reported to me four other cases, but only one nest was successful, in which chicks of both species, Blue Magpie and Cuckoo, fledged. During the feeding period, "helper behavior" by an individual hatched in the previous year was observed, which included feeding to chicks and females, taking away faeces and attacking enemies, etc.
The study was carried out on the bank surrounding ponds covering approximately 3.0 hectares and total 92 nests were surveyed. Males build the exterior of a few nests and after pairing, the pair use one of them as the real nest. Both male and female carry meterials for lining nest and complete the nest by the time when a full clutch is laid. Only females incubate, but when the eggs hatch, both male and female feed the nestlings. In this study area, all the nesting birds observed were monogamouse. Over 95% of the nests were found in clumps of Miscanthus sinensis and Imperate cylindrica. At the beginning of the nesting season in May the nests are low, but toward the end of nesting season in August, nests become higher from the ground. Of the nest exteriors made by males, 58.7% were utilized as a real nest after pairing. Nestlings were fledged in 42.6% of the utilized nests. The total number of eggs counted was 249, and the fledging success was 49.4%. Since the average clutch size is 5.7 eggs and annually there are two breeds, 11.4 youngs would be raised. But since the fledging success rate is 49.4%, one pair produce an average of 5 youngs.
The artificial insemination between a male and a female White-naped Cranes Grus vipio, kept apart, was tested. The semen was collected by the abdominal massage method of Archibald (1974) and Erickson (1975). After collection, undiluted semen was carried to Ueno Zoological Garden from Tama Zoological Park at normal temperature and was immediately inseminated to female. All eggs laid after insemination were put incubator. The average volume of semen collected by the abdominal massage method was 0.17ml (0.01-0.40), and the number of sperms 2, 250, 000-2, 480, 000/mm3 pH 7.16 (7.1-7.2). Of the 11 eggs laid by insemination, only one egg laid 4 days after insemination was fertile, from which a normal chick hatched.