1) Mating behaviour of the Japanese Wagtail Motacilla grandis was studied from 1983 to 1986 in Kyoto, central Japan.
2) Most male wagtails paired with only single female wagtails, but in five cases (2.2% of 225 breeding attmpts) males mated with two females.
3) Two patterns of mating process of the secondary females were observed: a widowed female stayed in her original range and mated with the neighbouring paired male; and a wandering female entered the territory held by a pair, mating with the paired male.
4) From simultaneous observation of two bigamous females, we confirmed that they spaced themselves out within the male's territory, having mutually exclusive home ranges, or that the primary female was dominant over the secondary female.
5) A bigamous male escorted and guarded his mates in rotation, and escorted the primary female longer than the secondary female.
6) The bigamous male helped little with feeding offspring of the secondary female, so that the secondary female had lower reproductive success than the primary female. This prevents bigamy in the Japanese Wagtail

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1) The social system of Azure-winged Magpies Cyanopica cyana was studied at Hizume, Nagano City, from 1983 to 1984, and at Kawanakajima, Nagano City, from 1962 to 1965 and inwinter of 1983.
2) The six months from April to September were defined as the breeding season, because pairs with or without their fledglings were observed during this period.
3) In the non-breeding season, flocks consisting of about 20 magpies were formed and the size of each flock was stable throughout the day.
4) In the non-breeding season, all members of a flock always roosted together. In winter and spring, different flocks sometimes roosted together without any antagonistic behavior.
5) The home range of Hizume flock was 1.2 km long and 0.9 km wide, and included 18 units of premises consisting of some houses and surrounding woods. Magpies spent longer time in premises with closed woods than those with sparse woods.
6) Home ranges of flocks seemed to coincide nearly with territories, because the home ranges overlapped little with each other and chases were observed around the boundaries of the ranges.
7) Flocks broke up into some pairs, non-breeding adults and subadults in the breeding season. At Hizume, nests of pairs belonging to the same winter flock were built 10-20 m apart from each other in a unit of premises, and the flock members visited the nests without any antagonistic behavior.
8) The fledging rate was nearly 50%. Families consisting of pairs and their fledglings were observed from mid-May to mid-September. Family members moved and roosted together in the nesting woods about one month after fledging.
9) There was no antagonistic behavior between families of the same flock. Some adults which had failed in breeding joined families, and one subadult fed fledglings as a helper.
10) Even in the breeding season, not only pairs but also some non-breeding adults and subadults of the same flock sometimes moved or roosted together. They showed defensive behavior against conspecific intruders or natural enemies such as domestic cats and crows.
11) As a conclusion of comparison among group-living birds, the Azure-winged Magpie was considered as a typical species which formed stable flocks throughout the year.

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1) Interspecific relationships between sympatric Great and Schrenck's reed warblers Acrocephalus arundinaceus and A. bistrigiceps were studied at Sugadaira (36°20′N, 138°20′E), central Honshu, during the breeding seasons in 1982-87. An intensive observation on the breeding schedule, home range and interspecific behavior was made in 1987.
2) Great Reed Warblers usually arrived at the breeding ground earlier than Schrenck's Reed Warblers. The earliest arrivals were male Great Reed Warblers, followed by female Great, male Schrenck's, and finally female Schrenck's reed warblers.
3) The mean staying period of mated males in the study area was about 60 days for both species. The home ranges of Schrenck's Reed Warblers were unstable as compared with those of Great Reed Warblers; Schrenck's often changed their home ranges.
4) Breeding success (fledglings/egg laid) in the study area was 40.4% for Great and 61.1% Schrenck's reed warblers in 1987.
5) In establishing home ranges the two species were segregated by time and space. Great Reed Warblers usually establish their home ranges earlier than Schrenck's. Schrenck's Reed Warblers had their home ranges either in the neutral area among the treat's home ranges or in the area distant from them.
6) The habitat preferred by the two species differed horizontally, although both species were overlapped in their preference for reed beds. Mean nest height was 1.02 m for Great and 0.63 m for Schrenck's reed warblers.
7) Three types of territorial behavior were observed: counter singing, chasing, and fighting. In Great Reed Warblers counter singing was noticeable. Great Reed Warblers often preferred tall trees for singing post, while Schrenck's selected reed stem for it.
8) Sizes of home ranges and singing areas of Great Reed Warblers were considerably larger than those of Schrenck's. Some males of Schrenck's Reed Warblers travelled from their home ranges to further places and sometimes established a second home range.
9) Territorial Great Reed Warblers were always dominant against intruding Schrenck's, whereas the latter could not successfully chased out the intruded Great Reed Warblers.
10) The two sympatric reed warbler species enabled to avoid competition not by interspecific territory, but by different time schedule for breeding and establishing home ranges. Schrenck's Reed Warblers had their home ranges in the neutral area between neighboring territorial males of Great Reed Warblers and made their breeding successful by non-territorial sneaking behavior

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A single White-breasted Waterhen Amaurornis phoenicurus was observed and photographed at a pond near the mouth of the Rekifune River at Taiki, Hokkaido on 30 September 1988. The bird was an immature. This was the first report on the occurence of the species for Hokkaido, although there was an unauthentic record of its occurence in Tomakomai in December 1983.

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