This is the 9th annual report of monthly census in the Imperial Palace in Tokyo from April, 1973 to March 1974. The same route of 4.1km was censused from about 9.40-11.30 a.m. as in the previous years. The results are tabulated in the same order of bird species only to add at the end additional species newly recorded for the year. Tallies were made in two basic tables, one for wooded area with small ponds, the other with big moats used as duck resort in winter and heron colony in summer. The number of species and number of individuals recorded per one census day ranged 15-32 (av. 23.9) species and 275-789 (av. 496.1) birds, which were slightly higher than in the previous year but reflecting a stable status of common birds. The total number of species recorded for 1973 was 53, which is 59.5% of the species so far recorded (89 species) during recent years, thus quite many species on the recorded list are lacking for 1973, as in each previous year. Four species, Eophona migratoria, Motacilla grandis, Otus scops and Falco columbarius, were added to the bird list of the Imperial Palace. The kingfisher Alcedo atthis reoccurred in 1973-74 winter after its disappearance since 1963. Some observations and records on the flocking, feeding and breeding (nest boxes for Great tit and Mandarin Duck) of birds, especially of the Great tit and Green Pheasant, are tabulated, with also some records of insects, etc.
1. Census data of forest birds obtained by the author and his coworkers during 1966 and 1972 in JIBP-CTS and other projects or private surveys, are here analysed tentatively by using 'bird community curves' and other graphs. 2. All the raw data were obtained by line transect census in which passing time through every different forest habitat was recorded so as to calculate number of individuals per hour (N/h), the 'time-density' of birds which can be used as abundance index. 3. The data of time-density (N/h) were presented in a 'bird community curve', drawn with N/h on Y-axis and species on X-axis, arranged left to right from high to low value of N/h. Thus, the curve combines the relative number of individual (N/h) and number of species, therefore quantitatively representing the bird community. 4. The position of each species or related species can be checked or indicated by special marks on a bird community curve for the purpose of comparative analysis. 5. The area between X, Y axis and bird community curve represent the carrying capacity of the habitat for that bird community, and may be used as the bird communty index of the habitat or as the index of habitat value for the bird community. These indices are of numerical nature based on N/h and relative biomass index can be calculated from it by multiplying species' individual body weight. 6. Ecological grouping of forest birds was made by rough divisions of upper, middle and lower forest layer inhabitants for the purpose of analysis of bird distribution in the forest of each type. Group A comprises tits and other small species of upper to middle layers, including insect and tree-fruit eaters. Group B consists of warblers, flycatchers, etc., the small insect eaters, chiefly of middle or lower layer. Group C, chiefly small or middle sized thrush group and wren, etc, of ground foraging habits. Group D, the ground foraging Emberiza spp., which are granivorous and insect eaters, including however tree bud eaters such as bulfinch or grosbeaks, etc., and also shrikes. Group E is represented by middle sized woodpeckers and cuckoos with specialized food habit. Group F is formed by midde to large birds which inhabit upper layer (crow family, etc.) or ground layer (pheasants) (Being very few in record the birds of prey are not included). 7. As the result, small birds are far dominant in number over others occupying all the upper, middle and lower forest layers and the middle layer of the forest is considered to be the layer where small birds have evolved their diversity without pressure of larger birds which chiefly inhabit upper or lower layers. 8. The bird community curves can be classified into principal 3 types: 1. Mixed forest type 2. Broad leaved forest type and 3. Needle-leaved forest type, with other combined types. These were shown characteristically by graphs based on data from 13 habitats in Mt. Fuji area. Curves obtained from data of many other mountains from Hokkaido to the Ryukyus supported these types or showed variations due to avifaunal differences in bird community (With decreasing palearctic species toward the south to the Ryukyus, therefore showing abreviated shorter bird community curves). The seasonal difference of bird community curves of a same forest type was also shown for habitats of Mt. Fuji area. 9. For relative comparison of habitat selection by related species of birds represented by time-density (N/h) in 13 different habitats in Mt. Fuji area, circle and rod graphs were also used.
1. Bird accidents recorded during 1965-1972 on highway passing 8km through the warm zone mixed forest of Ise Shrine ground were investigated 563 times in total. 2. This highway, with the width of 6.5m had a traffic of average 1, 500 cars/day in 1965 when it was opened. The traffic increased about 3.5 times by 1972 and the bird accidents (the annual relative kill) also increased 3.2 times during these 8 years. 3. The frequencies of No. bird kill/No. observation were 2/48 (1965), 6/120 (1966), 8/118 (1967), 8/95 (196), 8/80 (1969), 5/65 (1970), 5/37 (1972), with the total of 42 birds killed/365 observations (1965-1972), and increase from 7.4% annual relative kill in 1965 to 23.5% in 1972. 4. Bird accidents included 10 families, 18 species, comprising 72.2% residents, 16.7% winter visitors and 1/3 of the total of 42 kills were young birds. 5. The species of highest kill rate was 21.4% of redstart Phoenicurus auroreus, the 14% of Emberiza cioides, 7.1% of Cettia diphone, Parus varius and Streptopelia orientalis etc. and ground feeding Turdus included three species. 6. Seasonally, the highway kill of 19% of the total in March was the highest and the monthly kill was 10% during November to February, the winter kills from November to April occupying 87% of the total, which was about 3 times more frequent than in summer period. 7. The cause of death confirmed included 33% cranial internal hoemorrhages, and 14% visceral haemorrhages, which were caused by liver or even aortic breaks. 8. The accidents of birds were concentrated at 9 places along the highway of 8km. At these points small valley (s) with the width of 2-5m crossed the road at right angle, but at a broad open cross point of two big roads birds that move by low flight, such as bush warbler, pale ouzel, etc., were found dead. 9. Some observations showed that road-side birds would take off with the speed of 30-60km/h, and car speed retained at about 40km/h may usually be safe for the birds from being struck at.
The total number of wild geese migrating to Japan in recent years is estimated as about 6, 000-7, 000 and about two-thirds of them used to winter at Lake Izunuma, situated in the northern part of Miyagi Prefecture, Honshu. In January 1973. our bird census at Lake Izunuma revealed a flock of 3, 000 White-fronted Geese (Anser albifrons), 230 Bean Geese (Anser fabalis) and 3 Aleutian Canada Geese (Branta canadensis leucopareia (Brandt)). The majority of them had started from there to northward flight late in February. The junior author and Akio Watanabe observed early in March on paddy field at Hachirogata, about 2, 000 White-fronted Geese, 155 Bean Geese and 2 Aleutian Canada Geese. Hachirogata is located at the north-western part of Akita Prefecture, Tohoku district of Honshu, having an area of 22, 000 ha, and had been known as wildfowl resort since ancient days. Fifteen years ago, Hachirogata became reclaimed by drainage and now changed into large paddy fields. Our attention was directed to the appearance of Aleutian Canada Geese at Hachirogata. Since, the Aleutian Canada Goose is a rare bird, we concluded that the flocks of wild geese accompanied by 3 Aleutian Canada Geese had migrated from Lake Izunuma to Hachirogata on the way of north ward migration. Next year in 1974 we noticed the same phenomena, as listed below: Observed at Lake Izunuma Jan. Mar. 1974 (Most abundant number) White-fronted Goose … 4, 493 birds Bean Goose … 307 Aleutian Canada Goose … 2 Lesser Snow Goose … 1 Observed at Hachirogata Mar. Apr. 1974 (Most abundant number) … 3, 600 birds … 550 … 2 … 1 The Lesser Snow Goose (Anser caerulescens caerulescens (L.)) is also a rare bird and one wintering individual of this bird was recorded at Lake Izunuma during winter of 1974. It disappeared from Lake Izunuma on 24th of March and found at Hachirogata on 28th of the same month. The straight distance from Lake Izunuma to Hachirogata is about 170km and between the two places there are Oh-u mountain range and Mt. Kurikoma (1, 628m above the sea). In order to veryfy our presumption that wild geese fly along this straight line crossing over Oh-u mountain range to Hachirogata, we tried to obtain the informations by questionnaire to the villagers, farmers and hunters living beneath this flyway, whether they had seen wild geese passing high overhead on their way. We have collected 20 evidences that have witnessed passing wild geese within a period from autumn 1973 to spring 1974, and 29 persons answered that they had sighted during last sixty years passing flocks of wild geese high up in the sky. The migration course of wild geese has been hitherto supposed to be: (1) from Hokkaido southwards to Honshu, (2) across the Japan Sea to coastal prefectures in Japan, (3) along the Korean Peninsula to western Japan. Among them the first route, namely from Hokkaido to Honshu, is divided into two ways at Tohoku district (North-East District of Honshu), one way of which goes southward along the Pacific Ocean coast, and the other along Japan Sea coast, thus the the two ways run parallel and never meeting each other. But, we have added a crossing flyway from Pacific coast resort at Lake Izunuma to Hachirogata on Japan Sea coast, passing over Oh-u mountain range lying between them.
Long-eared Owl pellets were collected and analyzed during the breeding season of 1973 in the shelterbelts at Ishikari plain, Hokkaido. The shelterbelts consist of natural broad-leaved wood (Ulmus davidiana, Fraxinus mandshurica, Alnus japonica etc.) and planted trees (Populus nigra and Robinia Pseudo-acacia). The bush layer is thin but sasa-grass covers the ground densely. The prey taken were five species of Rodentia, one species of Insectivora and small sized birds. The main food of the owl was the Red-backed Vole Clethrionomys rufocanus, which was the most abundant species of small rodents in the shelterbelt (Table 1). The proportions of prey which appeared in the pellets roughly reflect the abundance of mammalian prey species which live in the shelterbelt and it seems that the owl was opportunistic concerning its predatory behavior. The average number of prey items per pellet was 2.6. The monthly age composition of Red-backed Voles which appeared in the pellets was similar to that of voles captured by snaptraps in a shelterbelt (Table 2. Fig. 2).
1. In 1971, Niigata Prefecture constructed a wildlife protection center, which includes pheasant raising and bird hospital. By April, 1974, 250 wounded or unhealthy birds of 52 species were treated and 18 of them were Ural Owls Strix uralensis, of which 6 were wounded (by car or shot) and 12 were nestlings fallen down from the nest. 2. This paper reports on Ural Owls about the treatment of wounds, cages (3.3m2 for wounded and 6.6m2 for recovered birds), food, artificial raising of chicks and hatching of eggs laid by protected birds. Also, their vocalization is described. 3. In March to April 1973, one of the protected owls (No. A) laid 5 eggs on the ground which were broken and confirmed to be unfertile after 21 days of incubation. 4. A fallen chick (No. D) picked up on 6 June 1972, laid 2 eggs, at 10 month old, on 27 March, 2 April, 1973 and one egg on 31 March 1974. 5. A wounded bird (No. F) protected on 25 March 1973, was kept with No. A from October and No. A laid 4 eggs on 14, 17, 21, 23 March 1974, of which 2 chicks hatched by artificial incubator. But they died on the 3rd and 6th days after hatching. After taking their own eggs (for artificial incubation), 4 chicken eggs were given which No. A incubated until 3 chicks hatched, but these were eaten by owls during that night. 6. All of D, H. and I chicks first uttered characteristic song at 8 month old after hatching.