1. Breeding biology and territoriality of Japanese Reed Bunting Emberiza yessoensis were investigated on Kirigamine grassland, central Japan. Observations were made by means of territory mapping and time mapping methods 1961-1971 on three quadrate plots. 2. On Kirigamine grassland, the Japanese Reed Bunting is a summer breeding resident arriving in May to June and departing in September. On arrival, males gather in small flocks in some parts of the grassland, before the females arrive. Pairs are formed after various consorting behaviours for the first brood. They begin the nest-building for the second brood while they are feeding their first brood fledglings. 3. The clutch size of the first broods was 4.5±0.72 and that of the second broods 3.6±0.53. Both sexes feed their nestlings and fledglings. The nestling period is about eleven to twelve days. Of the pairs which raised first broods, 42.9% raised the second broods. The nest success was 56.5% in total of breeding nests, 78.6% in first broods and 14.3% in second broods. 4. Detailed observations, especially of territorial and sexual behaviour patterns were described. 5. Frequency of territorial fighting by males fluctuated seasonally showing approximate bimodal curve. The first peak of this bimodal curve tended to coincide with nest-building stage and the second one with fledgling and second nest-building stages. 6. The intensity and seasonal fluctuation of singing activities were different between mated and un-mated males. That of the former had moderate singing frequency and the bimodal curve was coincident with the seasonal fluctuation of territorial fightings. The depression between two peaks results from male's increasing feeding activity for nestlings together with the female. The second peak of singing frequency is highest in the season. The curve of singing frequency of un-mated male rises as mated males enter the stage of nest-building, and the curve is maintained at the same moderate level during incubation to nestling stages of mated males. And, the highest peak of singing frequency of un-mated male parallels with the highest peak of that of neighboring mated males. 7. The nesting site of Japanese Reed Bunting is on or near the ground in grassy area. It is mostly (74.2%) constructed on or among the base of bunched Miscanthus using its leaves. 8. Fifty-five nestlings and eight adults were banded with colour rings. The recovery rate in next breeding season was 7.9% in nestlings, 40% in adult males, and 25% in adult females. The sites of recoveries were on or near the places where they were reared or in the previous territories. 9. The size and contents of home-ranges are different between mated and un-mated males. The average territory size of mated male was 4 to 5ha, while that of un-mated male was 7ha. 10. Male's singing area tends to change with the territorial range. The size of singing area was about 2ha, both in mated and un-mated males, except in 'temporal' singer. Mated males had several concentration of singing posts in their singing area, but un-mated males did not have such concentrated singing posts. The singing posts of bachelors were loosely dispersed in their singing area. Of the concentrated singing posts of mated male, one was located near the nesting site and others were scattered along outer parts for defense against neighboring males. Mostly, the nest was situated in or on the edge of the singing area. 11. Location of territories of mated pairs do not change seasonally, but those of un-mated males do. Although the site is different by year, un-mated males establish their singing areas in spaces vacant among stable territories of mated males. These un-mated males hold their vigorous singing centers and foreward singing spots to keep contact with stable pair territories. These temporal singing locations of un-mated males change with stages of breeding and by time of day.
1. Growth and survival of asynchronously hatched siblings in the Little Egret Egretta garzetta were investigated. A total of 13 broods was observed in two heronries in 1976 and 1977. 2. The growth rates of the first- to third-hatched nestlings were similar, and higher than those of the subsequently hatched nestlings. The fifth-hatched nestlings grew most slowly. The survival rate decreased with the sequence in hatching. 3. Two parents of a pair contributed almost equally to feeding the nestlings. The parents alternately stayed on the nest and fed the nestlings by intermittent regurgitation. During a single stay on the nest, which was average 175.4min, a parent regurgitated the food for nestlings average 7.3 times, until the first-hatched nestling was 10 days old. 4. Within a few days after hatching, nestlings changed the way of feeding from pecking a food bolus regurgitated on the nest floor to receiving a food bolus directly from the beak of a parent. The older nestlings adopting the latter way were usually advantageous to obtaining food. 5. When two nestlings were competitive in obtaining a food bolus, the older tended to take precedence over the young one. On the occasion when a large amount of food bolus was supplied, the younger one could also obtain food without competition after the older one had been satisfied. 6. Our observations support Lack's proposal (1947, 1954) that avian asynchronous hatching seems to be an adaptation by which brood sizes will be brought into adequate sizes corresponding with food availability.
During bird-banding operation of 1-5, May 1981, on Awashima, 63km north of Niigata City, the following rare species and subspecies were obtained. 1. Dupetor flavicollis Band No. 090-89101, May 4. First record for Japan. 2. Emberiza chrysophrys Three examples: Band Nos. 022-75873, 022-75874 (May 3), 030-60576 (May 4). So far considered as straggler, but may be a winter migrant in small numbers. 3. Emberiza tristrami Three examples: Band Nos. 022-75964 (May 4), 022-75994, 030-60579 (May 5). Also to be classed as rare winter visitor. 4. Emberiza spodocephala spodocephala Continental race spodocephala. Three examples: Band Nos. 022-75911, 022-75978 (May 4), 010-21429 (May 5). This race has been known by very few specimens from Japan proper. 5. Emberiza pusilla Two examples: Band Nos. 010-21419 (May 4), 010-21427 (May 5). This species may also to be called an uncommon winter visitor. 6. Emberiza aureola Band No. 022-75921 (May 4). A common summer breeder in Hokkaido, but very rarely occurs in Honshu, a new record for Niigata. A female was also observed. 7. Emberiza rutila Not banded, but observed and photographed (May 4), as new record for Niigata. Additional notes: A Locustella fasciolata when banded and being photographed, began to sing in the hand (Though it was quite different from its tipical song), Breeding of Falco peregrinus on Awashima was suggestive from its circling alarm flight (Formerly had been breeding until 1964).
A weakened Antient Auk Synthliboramphus antiquus in juvenile plumage was washed up on the beach of Niigata city, 26 July, 1980. Judging from sea currents, its breeding place on Awashima I. is suggested, though not known so far in this sea area of Japan Sea.