Diet of the Eurasian Hobby Falco subbuteo nesting in Western Aomori was determined from a study of food debris and parental pellets at five and seven nests in 2018 and 2019, respectively, and a video of parental feeding behavior for one nest in 2019 (Nest 2019 A). The food debris analysis indicated that the food items included small birds and insects, including 32 species of 21 families of birds, three species of one family of bats, and 24 species of 14 families of insects. The predated birds included Oriental Greenfinch (18.3% of preyed birds), Barn Swallow (17.9%), Chestnut-cheeked Starling (15.3%), and Eurasian Tree Sparrow (14.1%). Most of the predated insects were Cicadidae (52.8% of preyed insects) and Odonata (44.1%). In the parental feedings recorded by video, parents delivered insects (145 times) more than birds (23 times) to nestlings. These results indicate that hobbies breeding in Western Aomori mainly predated small birds and insects that inhabit the area around the nesting sites.

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We studied bird use of utility poles and overhead wires as perching locations in seven cities of Japan. Perch use included variations related to bird size and to seasonal patterns, including the following: (1) The ratio of perching on poles and wires to total perching sites varied among bird species. (2) Birds perched more frequently on poles and wires during the breeding season than during the wintering season. (3) The larger bird species tended to perch on poles rather than wires, and when perching on wires, they perched closer to the utility poles. (4) Many bird species perched more often on the uppermost wires than on the lower wires.

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Previous studies have shown that habitat preferences differ between Large-billed Crow Corvus macrorhynchos (formerly known as the Jungle Crow) and Carrion Crow C. corone in Japan. In this study, we observed the two species and identified the number of individuals observed in flocks, the heights above ground at which they perched and flew, the frequency of occurrence in four general habitat types in Hakodate (urban, agricultural, coastal, and mountains), and the variation of those observations among four seasons. Carrion Crows were observed to be more abundant in agricultural areas, and Large-billed Crows were more abundant in mountainous areas. Large-billed Crows were observed in flocks more frequently, and were observed to perch and fly higher than Carrion Crows.

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To assess the seasonal change of seabird abundance in the Tsugaru Strait, which is designated as a Marine Important Bird Area (IBA), we conducted surveys between Hakodate (Hokkaido) and Oma (Aomori) during 151 regular ferry transits from October 2006 to November 2010. We observed and recorded 51 species from 11 families of seabirds. The density of seabirds was highest during the spring migration period (April to May). In that period, the abundance of migrants such as Procellariidae (mainly Short-tailed Shearwaters Puffinus tenuirostris and Sooty Shearwaters P. griseus) and Red-necked Phalarope Phalaropus lobatus was highest. The species richness was highest during the late autumn to early wintering period (33 species in November and December). The Laridae (mainly Black-legged Kittiwake Rissa tridactyla and Mew Gull Larus canus) and Alcidae (mainly Rhinoceros Auklet Cerorhinca monocerata and Ancient Murrelet Synthliboramphus antiquus) increased during that winter season. Our results show the variety and seasonal abundance of various coastal and pelagic seabirds in the Tsugaru Strait.

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Pesticides are commonly used on golf courses for pest control. However, biological control using Eurasian Tree Sparrows Passer montanus is a more environmentally friendly substitute than using chemicals. For this purpose, it is necessary to specify the design of nest boxes that this species prefer. We examined the following two questions using data from Minegishi (2011). (1) What size of hole diameter and what ground height of nest boxes do this species selected, and (2) Whether the hole diameter and the ground height of the nest boxes selected by this species were the same as those suitable for their reproduction? The results showed that the Eurasian Tree Sparrow preferred nest boxes with a hole diameter of 30.82 mm, which was almost the same as that resulted in high reproductive success. The ground height of the nest box affected neither the percentage of nest box use nor the reproductive success of this species. Based on these findings, we concluded that the ground height of nest boxes should be anywhere between 140 and 370 cm and that the optimal hole diameter was 30-31 mm.

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We have discovered a new breeding colony of Streaked Shearwater Calonectris leucomelas on Takashima Island, situated in the Hoyo Channel on the southern edge of the Seto Inland Sea. We observed 122 nesting burrows without accumulated sediment, which indicates recent use, within 0.28ha of the breeding site. The island is located centrally between the three known breeding sites of Uwashima Island in the Seto Inland Sea to the north, and Okinokuroshima Island and Ojishima Island in the Bungo Strait to the south, forming a network of small colonies in this region. Infrared-triggered cameras were placed in the colony and identified three probable predator species, together with the shearwaters, using the burrows: rat Rattus sp., Pallas's Squirrel Callosciurus erythraeus, and Jungle Crow Corvus macrorhynchos. An eradication project is now reducing the population of the invasive Pallas's Squirrel on Takashima Island. The effect of rats on breeding shearwater should be monitored after the squirrel-eradication project, because the rat population may increase after the squirrel control because the species share food resources.

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I observed Barn Swallows Hirundo rustica breeding in November 2020 in Sendai City, Miyagi Prefecture in Northern Japan. Although Barn Swallows usually breed only in spring-summer in Japan, two autumnal breeding cases have been reported since 2019 in central Japan. The autumn breeding in Miyagi is assumed to be the northernmost case to date.

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Recent studies have revealed that Swinhoe's Rail Coturnicops exquisitus regularly overwinters in the Kanto Plain, Central Japan. Although some studies have suggested that the species also overwinters in other regions in Japan, only a few studies have assessed its status and distributions in winter. Here, we conducted the survey using a call playback method to confirm overwintering of the species at 10 survey sites in Okayama, Tokushima, Kagawa, Saga, and Nagasaki Prefectures, Western Japan. The surveys were conducted from January to February 2021. We confirmed five individuals at two survey sites in Saga and Nagasaki Prefectures, suggesting the species overwintering in Northern Kyushu.

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The Ministry of the Environment compiles information on injured and sick birds rescued by prefectures throughout Japan, and presents that data as 'Statistics on Birds and Animals.' Since this data set may serve to augment studies of trends in bird populations in Japan, the statistics from 1998 onward are presented here as a database. Data download: http://www.bird-research.jp/appendix/br17/17r01.html

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A national survey of birds has been conducted twice (1974-1978 and 1998-2002) and presented as "The Breeding Bird Atlas of Japan." From 2016 to 2021, we completed the third survey of this program. We conducted two complete survey courses within each cell of a 20km square mesh (total 2344 courses) placed as a graticule over the map of Japan. In addition to field surveys, literature information and bird observation records were collected and compiled to determine the status of birds in each 20km mesh cell. We release this dataset with the intention of providing useful data to researchers and conservationists, who may conduct various analyses to evaluate the distribution of birds in Japan during this period. Data download: http://www.biodic.go.jp/kiso/do_kiso4_bird_f.html#mainText

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Surveys of breeding birds of Tokyo were conducted twice (1973-1978 and 1993-1997) and presented as ”The Breeding Bird Atlas of Tokyo.” From 2016 to 2021, we completed the third survey of this program. We set survey courses within each cell of a 1km square mesh (total 2344 courses) placed as a graticule over the map of Tokyo. During this survey period, we conducted two field surveys in the early morning of the breeding season. In addition to field surveys, literature information and bird observation records were collected and compiled to determine the status of birds in each 1km mesh cell. Aiming at serving researchers and conservationists who seek to evaluate the distribution of birds in Japan during this period, we will release this dataset by aggregating the information into 5km mesh as a means of protecting rare species. Data download: http://www.bird-research.jp/appendix/br17/tokyo5km.xlsx

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