1)Data on time budgets, especially on the singing rate of male Great Reed Warblers were collected during the 1977 breeding season at Lake Biwa, Shiga Pref. in central Honshu.
2) Although the singing rate dropped dramatically with pairing, it recovered in the egg period of the mate and males during this period allocated time similarly as before pairing. Poly-gamous males acquired additional mates in this stage and it supports the hypothesis that song has a function to attract females.
3) Males just after pairing spent 40% of time consorting with their new mates. Consorting time declined sharply with the progress of nesting stage and a negative rank correlation was detected between the time spent consorting and singing before hatching of eggs. Care of the mate seemed to suppress the singing activity of males.
4) Males with nestlings or fledglings brought food to them and they sang little. Food collection for young deprived much potential singing time of males in this period.
5) Monogamous males during the egg period of the primary female sang as actively as polygamous males at the top of the vegetation, although they did not succeed in acquiring addi-tional mates. Bachelor males sang as many as others, but their songs were probably less effec-tive because some of them were uttered under the vegetation.

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In the polygynous Fan-tailed Warbler Cistcola junicidis, complete clutches and nestlings were frequently deserted by parent females late in the breeding stage.
1) Desertion by females inevitably means loss of offspring, because the eggs and young are left without parental care.
2) The mortality rate caused by desertion was 9.3% of eggs incubated and 15.2% of nestlings.
3) The desertion showed a strong seasonal pattern. Twelve (40%) out of 30 nests during and after August, were deserted in contrast to only three (1.9%) out of 160 nests before August.
4) Some proximate factors favoring such desertion are discussed. Self maintenance against delay of moult and migration seems to be important, although it is costly for females to desert grown offspring.

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1) The songs of the Siberian Meadow Bunting Emberiza cioides were investigated in Shinodayama hill, Osaka, from April to June 1980.
2) Individual birds were observed all day long. All song types of each bird were recorded and analyzed with a sound spectrograph.
3) Each bird had 65.9±8.9 syllables on the average (Table 1 and Appendixes 1, 2). Similar syllables were shared among neighboring birds (Table 2).
4) The first syllable of song tended to be unique for each individual (Fig. 2).
5) The mean duration of song was 0.9-1.4 seconds, containing 6.4-9.6 syllables. The mean number of song types per bird was 16.1±2.5 (Table 3).
6) The average bout length was 22.7-35.5 songs, while the average pitch was 7.8-12.6 songs per minute (Table 4).
7) Solitary males sang more frequently than mated ones. The mated males sang actively all day long in the incubation stage but sang only in the morning in the nestling stage (Fig. 4).
8) Among similar song types one song type was chosen over others from day to day (Fig. 6 and Appendix 3).
9) Song areas never overlapped each other (Figs. 8, 9). A particular song type was not associated with a particular song post (Table 5 and Appendix 4).
10) Birds tended to avoid the repetition of the same song type. They sang many more different song types early in the morning than in the rest of the day (Tables 5, 6; Fig. 10 and Appendix 4).
11) Two hours of observation in the morning suffice to record the complete repertoire of one bird (Fig. 11).

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Spring bird migration was investigated on Taira-jima Island (29°41′N, 129°32′E), Tokara Islands, Kagoshima Prefecture, from 1982 to 1987. Twenty nine families and 122 species were recorded in total and 66 birds with 30 species were ringed and released, including such unusual species as Muscicapa ferruginea, Turdus hortulorum, and Ficedula zanthopygia. Most species seemed to use this island on the way of the northward migration through the Ryukyu and Amami Islands. But several species, such as Erithacus cyane, Phylloscopus occipitalis, Regulus regulus, and Cyanoptilla cyanomelana are rare or unrecorded on the Ryukyus and Taiwan, suggesting a direct migratory course from south-eastern China to Kyushu.

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In order to investigate the seasonal fluctuation of damage intensity by doves, we sowed upland field of National Agriculture Research Center, Ibaraki Pref., with soybeans every other week and counted the number of soybeans damaged between April and August, from 1981 through 1986. Rufous Turtle Doves Streptopelia orientalis, the main predators on soybeans, were free to eat soybean seeds and/or cotyledons.
1) The percentage of seeds eaten before germination was low in April, high in May, and became low from June again. The percentage of seeds eaten in the first sowing of the year was always lower than the second sowing, probably due to that the doves are unaccustomed to the cropping field at the time of the first sowing.
2) The damage after germination (soybeans pulled out, growing point eaten, one or two coty-ledons eaten) was also intense in May but the degree of damage dropped in June. The percent-age of damage fatal to the plant (i.e. soybean pulled out and growing point eaten) was high when the percentage of total damage after germination was high.
3) The percentage of the number of soybeans (both seeds and cotyledons) damaged was high before the ripening of barley and became low just after the ripening.
4) The relationships between the seasonal fluctuation of soybean damage and the maturity stage of barley in other areas of Japan, the seasonal changes in the food habits of feral pigeons shot in the neighborhood of study area in spring, the change in behavior of Rufous Turtle Doves during the harvest period of wheat and barley, and the amount of barley and wheat that dropped on cropland at harvest were discussed. We suggested that a decrease in damage inten-sity of soybeans in June strongly related to the maturity stage of barley.

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Flocks of Ross's Gulls Larus roseus were observed along the coast of Shiretoko Peninsula, eastern Hokkaido, between 26 and 29 January 1984. On January 26, 24 adults and 8 juveniles in first winter plumage were seen at Maehama, Shari. They were hovering, circling, and occasionally surfacefeeding at sea 10-20 m off the beach. Sometimes they floated on the water, but did not dive. The flock moved from one place to another after foraging for about 10 minutes. Another flock of 67 Ross's Gulls was observed at the Shari Harbor at the same hour by another observer. Thus at least 100 Ross's Gulls were on the Shari coast on that day. Pack ice situated about 2 km off shore and there were brash ice and small ice cakes on the open water between the pack ice and the shore, the condition which seems to be especially favored by the gulls.
Next day (January 27) the flocks of Ross's Gulls disappeared from the Shari coast as the sea was covered by pack ice and no open water became available. However, several smaller flocks consisting of 5-27 birds were seen along the Shiretoko Peninsula between 27th and 29th. After January 30 the sea was closed by ice and no Ross's Gulls were observed. My observation supports those by DIVOKY (1976, 1981) and DENSLEY(1977) that Ross's Gulls chiefly feed at the edge of pack ice.

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