The breeding habitats and the local population size of Japanese Marsh Warblers Locustella pryeri were surveyed annually from 2007 to 2014 in Watarase Marsh, Tochigi Prefecture. The warbler began breeding at the marsh in recent years, and the number of territorial males increased during the study period. Notably, the breeding population increased by eight to fifteen males after 2010, when large patches of reeds remained in the study site in March and April, instead of the reeds being removed by typical controlled burns. Two major factors are assumed to be related to the increasing warbler abundance in the study site: the general increase in the breeding populations at the major breeding sites in other parts of Japan, and the persistence of unburned reed beds in early spring, which is the crucial season for acquisition of territories by males. Large patches of older reed beds remained in the study site in 2010 due to wet weather, and in 2011 and 2012 due to the cancellation of the prescribed burning of the reeds. The vegetation in the study site was composed of tall monocotyledons such as the common reed Phragmites australis and the Japanese silver reed Miscanthus sacchariflorus. The reeds had a density of 16.2±9.1 stems / km² at ground levle, and a height of 209.2 ± 32.7cm. The understory was composed of dense sedge cover. The warblers tended to occupy territories within a limited area of the study site, which suggests that the local population had not yet begun to disperse into habitat patches with lower quality.

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I recorded the seasonal fluctuations of abundance for Eastern Marsh Harriers Circus spilonotus and Hen Harriers C. cyaneus wintering at two sites in Okayama Prefecture from 2011 to 2014. Individuals were identified by external plumage and morphological characteristics. The peak period for arrival of Eastern Marsh Harriers was between October and December each year. The peak of their roosting abundance was between October and February, when the arrival of newcomers augmented the number of regularly observed individuals. The peak of roosting abundance in Hen Harriers, on the other hand, was reached between December and January. This period for peak numbers of roosting Hen Harriers was different from that of other wintering sites in Japan. The peak of roosting abundance for Hen Harriers is assumed to be influenced by the location of the roost site relative to the migration route.

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Hunting flights by Eastern Marsh Harriers Circus spilonotus were studied to investigate the effect of ponds created for restoration in Watarase Marsh, Tochigi Prefecture, Japan. The frequency of hunting flights, hunting behaviors and time spent (minutes) on hunting flights were recorded from mid-October to November of 2004 and 2014, and from January to February of 2015. The study area was classified into two habitat types, including a restoration site with newly created ponds, and a dry reedbed consisting of common reeds Phragmites australis and Japanese silver reeds Miscanthus sacchariflorus. In November of 2004, before the creation of ponds, the frequency of hunting flights by harriers were significantly more frequent in dry reedbed than at the restoration site. From mid-October to November of 2014, after the ponds were created, the frequency of hunting flights and hunting behaviors by harriers were significantly more frequent in the restoration site than in dry reedbed. In the autumn season, the newly created ponds had numerous waterfowl such as ducks, grebes, and Coots Fulica atra, which are major prey species of the harrier in the study site. The duration of hunting flights was also significantly longer over the restoration site than at the dry reedbed. From January to February 2015, however, there was no significant difference between the two study sites in the frequencies of hunting flights and hunting behavior, nor of the time spent during hunting flights. At the restoration site during that time, the availability of waterfowl as prey appeared to be poor. In order to create ponds as hunting habitat for the harriers throughout the wintering season, therefore, it is necessary to construct wetlands with ponds that have more suitable structure for wintering waterfowl. This can be accomplished by managing water depth and vegetation structure.

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Sympatric breeding of Russet Sparrow Passer rutilans and Tree Sparrow P. montanus was observed during 2013 and 2014 at a camping site at Ogawara Lake in Aomori, Japan. In 2013, both species began to build nests almost simultaneously. Two of three Russet Sparrow broods and two of four Tree Sparrow broods successfully fledged young. The distance of the nearest adjacent nests of the two species was about 2m. Of those neighboring nests, the Russet Sparrow succeeded in fledging young, but the Tree Sparrow failed. In 2014, we established 20 nest boxes at the study site. Six Russet Sparrow broods, including a pair that used a natural cavity, were observed that year. Although Tree Sparrows did not nest in 2014, they visited 700m from their nest only to forage in and below cherry trees at the site. A pair of Russet Sparrows was assumed to have bred in a nest box stuffed with moss, which suggested that the box was used previously by one of the Parus species. Hada (1953) advocated a "Rutilans Line" that demarcates preferable habitat for Russet Sparrows in areas where the average annual temperature is below 10 degree Celsius. Such cool climate conditions occur at this study site due to the “Yamase” cold winds of early summer.

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We report a recent increase in the number of visiting Snow Geese Anser caerulescens as passage migrants visiting Mawarizeki Pond, Aomori Prefecture, Japan. Between 2005 and 2015, we counted the number of geese 1 to 2 times per week during October through December. The annual number of geese visiting this site grew rapidly, concurrently with the population increases observed at other rest sites in Japan. Mawarizeki is a pond with a large area of adjacent farmland, and it seems to offer an appropriate rest site for flocks of this species during autumn migration along the route from Urahoro, Hokkaido, to Hachirogata, Akita.

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I studied the diving behavior of Teal Anas crecca in the Nishi River of Wakayama Prefecture, which is located in western Japan. As part of a larger study of Teal populations in the river, which was conducted from October 6th, 2010, to May 31st, 2015, the diving behavior was observed from January to February in 2011 and from October to November in 2014. The percentage of teal observed diving was 1.8% (405 individuals) of the total number of individuals observed (n=22,592 teal). There was no relationship between sex and occurrence of diving behavior. The diving duration was 3 to 6 seconds / dive. The teal appeared to dive for feeding, because the teal that dove were observed to consume algae after they had surfaced.

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We recorded songs of a Large Hawk-Cuckoo Hierococcyx sparverioides at Tairajima Island, Tokara Isles, Kagoshima Prefecture, Japan, on May 26, 2012. This is the first audio record of Large Hawk-Cuckoo songs in Japan. The species was identified by comparing the sonogram of the recorded songs to other confirmed recordings of Large Hawk-Cuckoo and related species. This species was observed on the same island for 4 consecutive years starting in 2012.

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