The succession of terrestrial ecosystems (seres) is studied in aspects of structure, function, production and energetics of the participating organisms. All aspects mentioned involve history and evolution of the communities integrating the ecosystems. The first approach is the structure, which is particularly dealt with in the present paper. Obviously, most knowledge of ecosystem succession regards the first step only. It indicates the need of study of other aspects, also, and a want for a clear image of structure. Birds and mammals take part in almost all terrestrial ecosystems. Within the seres of a particular succession-primary and secondary we recognize three, mainly dynamically defined groups of higher vertebrates named, viz. 1) progressive species entering populations, 2) regressive, disappearing species and 3) conservative constant species populations, called in the present paper the core of series. Some problems of structure, the sources from which group 1 penetrates and the function of the particular groups are there dealt with, based on author's own materials and data from some literature.
This is the 7th annual report of monthly (except August for this year) census in the Imperial Palace from April, 1971 to March, 1972. The same route of 4.1km. was censused usually from 9.40 to 11.30 a.m. The results are tallied by two areas, one including moats of winter duck resort (chiefly Anas poecilorhyncha and Aix gelericulata) and heron (egrets) colony. The monthly species records in total area ranged 20-29 (av. 23.4) and the number of individuals 256-609 (av. 383.2). Only two species, Acrocephalus arundinaceus and Bubulcus ibis were added to the list, making a total of 49 species for 1971 and 81 species so far recorded. General avifauna was rather stable annually but egrets and ducks are decreasing, perhaps reflecting the effect of pesticides used in the field (dead egrets were found in the area), and the heron colony is attacked by Corvus macrorhynchos. Tables of feeding observation, dead birds, flock components of Parus major and Phasianus versicolor are presented.
1. The structure and distribution of pair territories of Aegithalos caudatus in breeding season was studied. Then, the winter flock territory was discussed in comparison with them. The field studies were made at foot zone in 5 breeding seasons during 1964 and 1968. The habitat was mixed woods of middle Honshu, Japan, consisting of Quercus serrata, Castanea creata, Larix leptolepis and Pinus densifrora. 2. Breeding territorialism was discussed with analyses on pair behaviors, distribution of activity loci, movements, fighting behavior and helpers. 3. The pair formation behavior was not observed in spring but was confirmed in summer and autumn of the previous year. Pairs split from winter flock, and at interval stage of pair formation, one or several pair flocks existed. These flocks were involved within their common range of winter flock. The range of pair flock was communally defended by members of the same flock against adjacent such flocks. Pairs occur in the winter flock and gradually become isolated with each other, but never go out of the winter flock range. 4. At night, all the pairs assemble to one winter roost, but during the day each of them is engaged in nest-building at separate place. In early spring, nesting is done only in the morning, returning to flock life in the afternoon, especially when the weather is bad. As breeding season advances, pairs remain more of the time in their own territories. 5. Pair ranges established by dividing a winter flock range are considerably overlapped, especially at their previous center of the flock. The pair of dominant male first become independent against the group of pairs of subordinate males, which settle at or near the flock center. 6. During early stage, all the pairs splitted from a common winter flock make a group and communally fight against the members of other such groups. At the stage of completion of outerwall of the nest, pairs roost in it and completely isolate themselves from the flock. 7. The highest frequency of fighting is seen in nesting period when copulation occurs, and thus the territoriality in this species becomes the most evident and its territorialism is perfectly established. After that, the fighting frequency and territory size markedly decrease. Under such condition, the social structure settles and production of the next generation is under way. But, in reality, this stable condition is greatly disturbed by predation on their nests and various behaviors of renesting are resumed. 8. A pair has a few central areas with highest activity density which never overlap with those of adjacent pairs. The patrolling course for maintaining the pair range starts from the central area and return to it. On patrolling along the periphery of the pair range, the pair would fly against the adjacent pair when they meet. 9. The male show many available nest sites to the female who determines one of them as their nest. The male after this event performs several nest-invitation displays which remind behavior patterns of courtship and mating. The nest is not necessarily located at the central area, though in most cases it is found in or near it. Although the nest is made often in a branch of pine, typically it is concealed in a dense bush. 10. Pairs renest when the first nest is destroyed, often beyond a few adjacent pair ranges. However, the site of renesting is never selected outside of the winter flock range and tend to be correlated with the previous activity range. 11. In nestling and fledgling periods, the helpers are observed, but never before that. The helpers consist of unmated birds and unsuccessful breeding pairs. As soon as young birds become independent from the parents, the helpers and young birds make a family flock with the parent birds.
1. From 1963 through 1967, the roosting behaviour of Jungle Crow Corvus macrorhynchos and Carrion Crow C. corone was studied in Mie Prefecture. 2. Habitat segregation was observed between the two species; C. macrorhynchos from mountains to hills, and C. corone from hills to plain. 3. From feeding ground to roost, roosting flocks were formed in four processes: feeding ground pairs and flock-flight line assembly-pre-roosting assembly-roosting assembly (roost). 4. In the process of pre-roosting assembly, initial assembly place differs in the two species. Assembly place of the earliest flock tends to be the pre-roosting assembly place of the day. 5. Numbers at the pre-roosting assembly place, were correlated with the light intensity. Numbers increased remarkably under the light intensity about 100 lux. 6. Seasonal fluctuation of numbers at roosting place was at its maximum from December through February and minimum from April through August. This is caused partly by the dispersion of the roost, and partly by the fact that most of the breeding crows roost in their territories. 7. The number of roosts in the breeding season was seven in the northern part of Mie Prefecture. Roosting numbers were 200-300, most of them non breeding birds, but some breeding birds were mixed. 8. The autumnal roost was not found in the northern part of Mie Prefecture. 9. The number of winter roosts was ten in Mie Prefecture. Roosts were mainly found beside the river. The area of dispersal from the roost was from 400 to 500km2. 10. Roosts are usually found in the forest well protected from long before. In Mie Prefecture, Pinus thunbergii woods were most often used. 11. Total number of two species of crows in Mie Prefecture was estimated as about 20, 000, based on maximum roosting numbers in winter.
Winter (Kuroda 1969) and autumn (1970) bird censuses of the Ryu Kyu Is. have already been reported. The present paper is the result of the survey planned by the Ornithological Society of Japan, principally for analysis of the status of Sapheopipo noguchii of Okinawa I. This will be reported elsewhere. The bird census was made on Okinawa I. 24-28 May in the northern mountain zone, on Ishigaki I. 31 May and 5 June and on Iriomote I. 1-4 June. The weather was fine except on 5 June. In total, 51 species, 30 land, 16 water or waterside, and 5 sea birds, were recorded. The land bird species were 24 on Okinawa, 15 on each of Ishigaki and Iriomote. These land birds are residents and show the reduced number of breeding species in these subtropical islands where palearctic species (such as thrushes, flycatchers, warblers and tits, etc.) decrease or disappear and tropical elements are represented only by few species. The number of individuals is also generally low, especially in the montane zone in spite of the excellent and extensive forests. This may be due to the distributional periphery for both palearctic and tropical species. The most generally abundant species was Hypsipetes amaurotis with the dominance of 21% in totalized avifauna, followed by Streptopelia orientalis of 18% of dominance. This species was particularly abundant on Iriomote where it gathered on a few small coastal islets (Hatopanare, Usagi (newly named islet), etc.) for breeding (and roosting). They nested on the ground under dense grass and all had laid two eggs, with the density of a true colony, and flew out to perch on rocks or dead shrubs by small flocks. The environmental safety and potential habit of oversea dispersion of the pigeons and doves may, among others, be attributed to this peculiar island concentration. Three birds were seen flying low over the sea surface from the main island to the offshore island of Hatomajima, km apart. The next was Zosterops palpebrosa of the general dominance of 8%, but more may have been missed in the census. Cettia diphone was even more abundant with the dominance of 22% than Hypsipetes on Okinawa, but was not recorded on the other two islands. Next were dominant Passer montanus (common on Ishigaki but absent from Iriomote), Corvus macrorhynchos and Parus major and the subtropical nature of the avifauna of Ryu Kyu Is. was well characterized by such species with medium dominance, as Terpsiphone atrocaudata, Pericrocotus roseus, Parus varius (not encountered on Ishigaki and Iriomote this time), Cisticola juncidis, Halcyon coromanda, Otus scops, Sphenurus sieboldii and Turnix suscitator, etc. Coastal and marsh birds were not plentiful, egrets and waders having already passed north, and only a few remained. On extensive saltflats small flocks of Tringa brevipes, Tringa nebularia and one Tringa totanus were recorded. An Ardea purpurea and Sterna hybrida were found on Iriomote at the same places where they were seen in 1970. Ixobrychus cinnamoneus was common on rice fields with Gallinula chloropus. Alcedo atthis is said to have decreased due to the recent use of insecticides, and only one was seen in a mangrobe of Iriomote. Sea birds recorded were five species, Sterna sumatrana was arriving north to Okinawa and was seen in pairs. Its breeding places on small coastal rocky islets, Hatopanare off the north coast and other two islets off the western coast of Iriomote were first confirmed, but they were not laying eggs yet. Some flocks of Sterna fuscata were seen north of Iriomote, probably with the seasonal migration of the bonito to this sea area where schools of small fish were seen chased to the surface and a flying fish was observed.
We observed several flocks of the ground linnet Leucosticte arctoa at high levels of Daisetsu Mountains, central part of Hokkaido, during the summers (August) of 1970 and 1971. Some of the individuals observed had a juvenile-like plumage pattern and one of them was being fed something by an adult male (Fig. 4). Though it was not proved that the individual was a juvenile fledged in this season, this may suggest the breeding of the species in this area.