At a permanent pair territory of Jungle Crow Corvus macrorhynchos in Tokyo, a total of 454 morning and 95 night return-flights from communal roosts were recorded through the seasons, 1972-'79. The distances from roosts to territory were 1km in summer and 4km in winter. The arrival time to territory was analysed with regard to month, season, and weather. Usual morning arrival from roost to territory was recorded from 0 to 70 minutes before sunrise. They were average 26-27 minutes before sunrise in spring or autumn, about 21 minutes in short-nighted summer and about 30 minutes in longnighted winter, thus probably correlated with the length of daytime feeding period. But, in spring, especially April, the breeding activity may suppress the above daylength factor, awaking early for feeding even during short-nighted period, thus consuming energy owing to short night rests. The morning movement was earliest and variable in fine weather, then in cloudy condition and was latest and least variable on rainy days, which suggested bird's inactiveness in rainy weather. The night returns were recorded from August to April, the peak season of night returns being November to January (52% of all records) prior to breeding, and 58% were recorded on fine, 28% on cloudy and 12% on rainy days. As for time, 73% were recorded between 1-3a.m., 16% 23-24p.m., 7% 20-22p.m. and 4% after 4a.m. It is not clear whether this is a natural behavior or is peculiar to crows of cities, but should reflect the territorial adherance before they acquire their stable breeding conditions. The original data of morning returns to territory from roost were statistically calculated by means of multiple range test and T-test, to analyse, 1. Inter-seasonal test by weather 2. Inter-weather test by seasen 3. Inter-weather test by month and 4. Inter-menstual test by season. These showed significant differences of winter return times from those in other seasons (spring and summer), fine-weather return times by seasen and month, while least variable were times in rainy weather.
The breeding season of the White wagtail Matacilla alba (from April to July) completely overlapped that of the coexisting Japanese wagtail Motacilla grandis which bred in and around towns. Both species built their nests on buildings, and some of these two species used exactly the same nest sites. Males of the White wagtail contributed to 8% of nest building, 6% of incubation, 36% of chick-feeding and 28% of faecal sac removal. These contributions were less than those of the male Japanese wagtail in incubation and chick-feeding. One of the two main food items for nestlings of both species was found to be the same, that is, the insect family Tipulidae. Japanese wagtails obviously dominated White wagtails in the breeding season. Although the interspecific aggressiveness of Japanese wagtails towards White wagtailes was not so severe as that towards conspecifics, it was sufficient to decrease the male White wagtail's part in incubation. This aggressiveness may be a cause of habitat segregation between the two species in the overlapping part of their breeding ranges.
During the bird-ringing in seven autumns (from late September to late October) in 1975-81, in Hokkaido, Japan, we studied the moult and clue of aging of the Marsh, Parus palustris, and Willow, P. montanus, Tits. (1) Both two species were in late stage of moult. Sixty-five per cent of 269 birds of the Marsh Tits and 73 per cent of 124 birds of the Willow Tits were moulting, at least, one of body-feather tracts; only two birds of the Marsh Tits were moulting their greater coverts; and 5 per cent of 269 Marsh and 2 per cent of 124 Willow Tits were moulting their tail, in pooled sample of seven seasons. (2) For the Marsh Tit, likewise some passerine species, the vanes and shafts of adult and renewed first winter juvenile rectrices tented to be harder and wider, and the tips more round than in the juvenile rectrices. These features were useful guide to age the species until, at least, late October, since most of the juveniles did not moult their rectrices. This was only one clue of aging the species by the plumage. (3) It was confirmed that, as mentioned by Svensson (1975), the examination of the pneumatization of skull roof is a useful to age the Marsh Tit, and probably in the Willow Tit, until, at least, late October. (4) Most of two species captured during these seven seasons seemed to be the juveniles.
In the previous paper we showed the morphological differences between the Marsh, Parus palustris, and the Willow, P. montanus, Tits under the urgent necessity of claryfying the identification criterion (Abe & Kurosawa 1976). It seems that this paper is still a useful guide for Japanese ringers, although there was careless error in the description on the longest and shortest tail feathers and the sample sizes were rather small. In the present paper larger samples taken at Hokkaido in seven autumns of 1975-81 are treated. The measurements are given in Tables 1-5; these percentage-distributions are shown in Figures 1-7. The ranges of all measurements of two species were overlapped, however these two species could be separated most clearly in the bill depth, the ratio of bill depth to exposed culmen and the graduation of tail. There was considerable variety in the longest and shortest tail feathers. It seems probably because the growth of juvenile tail feathers and the number of feathers renewed in postjuvenile moult are irregular and inconstant (Abe & Kurosawa in prep).
For the one form, Cettia diphone cantans, of Bush Warbler, it is well known that the colouration of the sexes is identical and that the general size is considerably different between them, though the numerical data of wing length have not been published sufficiently. An aim of this paper is to find a sexing criterion of cantans in autumn routine ringing. The data of this paper were obtained at Otayama Bird Observatory during autumn ringing from 1974 to 1981. One hundred and twenty birds were composed of 92 first winter juveniles and 28 adults. The measurements of wing and tail lengths of these birds are given in Table 1, and Figs. 1-4. Both wing and tail lengths were apparently bimodal. Based on the frequency distribution of wing length, these birds were divided into two groups; Group-A, birds have wings shorter than 61mm, and Group-B have wings longer than 60mm. It seems that these two groups are females and males, respectively. The separation point of the sexes as a criterion was proposed: the birds have wings (1) shorter than 61mm are females, (2) longer than 62mm are males, and it is safe to write (3) 61mm or 62mm are not decidable.
Birds of an agricultural land were censused by the line-transect method at the Obihiro University Farm in Obihiro, Tokachi District, Hokkaido from 1976 to 1983. The study area is a mosaic of cultivated fields, pastures, shelterbelts of larch, forest islands of deciduous trees and farm facilities. A total of 76 species of birds was recorded by censuses of 92 times during the study. The number of species was 19 to 23 from January to March, then increased to 39 to 40 by recruitment of summer visitors. After August it decreased as summer visitors left the study area. Seasonal change in the number of birds for all species was similar to that of the number of species except in September and October, in which more birds of Passer montanus and Carduelis sinica were counted than in other months. In breeding season main species included Passer montanus around farm facilities, Emberiza spodocephala and Anthus hodgsoni at forest island, Saxicola torquata and Emberiza aureola in pasture, and so on. During winter Passer montanus and parid birds dominated. Avifauna at agricultural land was characterized by mixed one of both forest and grassland birds.
A Spotted Eagle Aquila clanga was found dead on the shore of Maki-machi, Nishikambara-gun, Niigata Prefecture on February 12, 1984. Only a few records of this species were reported so far in Japan, and this is the first record both from Niigata Prefecture and along the coast of the Japan Sea. It was the female juvenile and its weight was 950g.
Between May 3 and 6, 1984, the authers did bird banding work on Mishima, an isolated island about 45km north-west of Hagi City, Yamaguchi Prefecture. During the period, they caught a Dusky Warbler Philloscops fuscatus which had been never recorded in Japan. The bird was mesured, photographed and then released.
1. M. Berezovsky who took part in the west China expedition under the command of G. N. Potanin, 1884-1887, observed colour change on plumage of Japanese Crested Ibis near Hoi-cyan, Gan-su province, west China, 1884-1885. 2. M. Berezovsky and V. Bianki (1891) described the result of Berezovski's observations as following items. a) All Japanese Crested Ibises observed in December have white plumages. b) In the end of January some of the birds have faint grey tint on the head and neck. c) In February some greyish birds are seen more often. By the end of this month some white ibises are met as exceptions. d) It is confirmed that the colour change takes place on the same birds, and that Nipponia nippon, var, sinensis described by A. A. David and M. E. Oustalet (1877) because of its grey plumage is nothing but Nipponia nippon itself with summer apparel. e) Spots where formation of black pigment takes place are found in the skin of head and neck. These are observed at the external surface of the skin, but particularly pronounced on the internal side. f) The change of colour begins in the end of January and is over by March, but during the whole time interval the behaviour of ibises is without any sign that would indicate beginning of the breeding period. g) Its plumage is white only in autumn and winter; they are grey in spring and summer. This fact is agreed by almost all data from China, Ussury-area and Japan which have descriptions of plumage colour and the time of observation or hunting. h) Nothing is known in the autumn change of apparel or moulting of the birds. 3. This description did not call any attention to every ornithologist except Karl Deditius (1897) who mentioned "Das mitgebrachte Material beweist vollkommen, daβ Ibis sinensis ein Sommerkleid von Nipponia nippon ist, " and Ernst Hartert (1936) who referred to Berezovski's pronouncement, but did not accepted it. 4. The author is grateful to Dr. Irina A. Dubrovo, Palaeontological Institute of the Academy of Sciences, U. S. S. R., for searching for this description and sending it to him and to Miss Kimiko Koshikawa for her help in translating old Russian of this description into Japanese.