To determine the effects of substrate characteristics and macrobenthos abundance on the abundance and species richness of shorebirds, field surveys were conducted on the northern (Funabashi Sanbanse Bay Park and Yatsu-higata) and western tidal flats (upper and lower Tama River estuaries) in the inner part of Tokyo Bay, Japan, in August and September 2014, and in April, May, August and September 2015. The shorebird abundance and species richness were greater on the northern than on the western tidal flats throughout the study period, due mainly to greater species richness and abundance of two foraging groups (pause-travel and tactile-continuous) present in the northern area. The most dominant species in the pause-travel and tactile-continuous foraging groups were Pluvialis squatarola and Calidris alpina, respectively. Analyses of the relationships between the densities of both dominant species and a variety of environmental variables on the tidal flats, using generalized linear mixed models, indicated that the abundance of large, and large and small polychaetes may be the most important determinants of P. squatarola and C. alpina densities, respectively. These results suggested that the distribution pattern of shorebirds in the study area is primarily influenced by polychaete abundance.

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The jungle crow Corvus macrorhynchos and the carrion crow C. corone in urban and residential areas often damage plastic garbage bags, by ripping open the plastic, and scatter the contents. Their foraging behavior on garbage (trash) bags causes littered and stinking streets, and decreases the efficiency of garbage collectors. To solve the problem, we need to determine the best way to protect the garbage from crows while the bags wait on the street for collection. We obtained three findings after researching 2000 garbage bags during the winter of 2015–2016 in Hakodate City. First, the garbage bags placed in front of apartment houses were ripped open more frequently than those placed in front of detached houses. This may be because people living in detached houses are personally responsible for cleaning up their own litter when their garbage is scavenged by crows, so they pay more attention to the manner in which they dispose of their garbage. Second, garbage bags were ripped open by crows more frequently when the bags were either unprotected or when covered only by a nylon net or a blue plastic sheet. Those placed in various types of containers, such as a steel mesh basket box or a plastic basket box, were less frequently opened by crows. Third, garbage bags placed in steel mesh basket boxes with additional protection, such as when mesh sides were covered by a wooden or an acrylic board, were less frequently ripped open by crows than those placed in steel mesh basket boxes without additional protection. These three findings suggest that to solve the problem, (1) people living in apartment houses should pay attention to the manner in which they dispose of their garbage, (2) a container with lid should be used instead of a nylon net or a plastic sheet, and (3) when using a container with mesh sides, the mesh sides should be covered with a wooden or an acrylic board to prohibit access by crows.

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I studied the characteristics of roosting habitat for Eastern Marsh Harriers Circus spilonotus and Hen Harriers C. cyaneus in Okayama Prefecture from October 2011 to September 2015. Harriers were observed to roost in three types of reed bed habitats, include sites with reed and sedge, sites with reed only, and parts of the reed bed where the reed was lodged by wind. Reeds are said to be “lodged” after wind has blown them from a vertical to a partially horizontal position. The majority of Eastern Marsh Harriers and Hen Harriers roosted in habitat with only reeds. Eastern Marsh Harriers, however, changed roost habitat seasonally. In July to October, use of reed-and-sedge habitat decreased, and use of the reed bed sites where the reed was lodged by wind increased. It is assumed that the seasonal changes of roost habitat was influenced by temperature, risk of predation, and density of plants.

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In Hokkaido, northern Japan, accidental collisions with wind turbines have become one of the largest conservation issues for white-tailed sea eagles Haliaeetus albicilla. To investigate whether the presence of food in the vicinity of wind turbines may result in behaviors that increase the risk of collision, feeding experiments were carried out at a safe location in Hokkaido from 2014 to 2016. For both white-tailed and Steller's sea eagles H. pelagicus, the frequency of flying looking downwards increased when the food was placed on the ground. Furthermore, the frequency of interference by other individuals also increased with feeding. It is known that eagles can visually recognize the wind turbines in front of them, but that they cannot recognize the structures when flying looking downwards. These results suggest that the presence of food in the vicinity of turbines induces behaviors that may increase the collision risk with wind turbines for both white-tailed and Steller's sea eagles.

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The winter distribution of the endangered Ryukyu Robin Larvivora komadori was surveyed on eight islands within the southern-most island group of the Ryukyu Archipelago of Japan. The surveys were conducted in the Sakishima Island group, including Miyako-jima, Ishigaki-jima, Taketomi-jima, Kohama-jima, Kuro-shima, Hateruma-jima, Iriomote-jima, and Yonaguni-jima. Survey points were randomly located near suitable habitat, including forests or woodlots, and a playback method using the robin's song was used to enhance detectability. Robins were observed on all the islands that were surveyed, and 364 individuals were observed or heard at 300 out of 853 survey points. The scarcity of the past records of this species may be attributable to its low detectability. The species has limited vocal activity in winter, and its habitat preference for dense shrub vegetation in forested areas makes it difficult to observe visually. The plumage characteristics of the 53 individuals observed visually were consistent with those of the northern subspecies L. k. komadori, which breeds in the Amami and Tokara Islands, at the northern end of the Ryukyu Archipelago. The wintering robins were commonly found in evergreen broad-leaved forests, or in small woodlots around coasts or villages. In view of limited availability of these types of areas as wintering habitat for the robin, various types of forest should be taken into consideration when planning effective conservation measures for this species.

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To determine the avifauna of the small offshore island of Shinojima, which is located off Mikawa Bay in Aichi Prefecture, surveys were conducted from January 2014, to September 2015. During 18 surveys I recorded 58 species, 18 of which were assumed to be residents, one a migrant breeder, 20 winter visitors, and 13 were passage visitors. Ten of the 18 resident species were observed in various habitats. It seems likely that those species have a stable presence on this small island because of habitat generalization. Japanese Pygmy Woodpecker Dendrocopos kizuki and White Wagtail Motacilla alba colonized Shinojima Island and became a resident species. In the 2000s, those species expanded their distributions as residents on the Aichi mainland. They may have recently expanded their resident range to Shinojima Island. Pacific Reef Heron Egretta sacra was a resident species on Shinojima Island, but they are not a common species in mainland Aichi Prefecture. They are assumed to prefer the island to the mainland as habitat in Aichi Prefecture.

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A call playback survey of wintering Japanese Marsh Warbler Locustella pryeri was conducted at 32 wet-grasslands within the Kanto Region from late December to early February in 2014-2015 and 2015-2016. We located 94 individuals at 13 survey sites. Four occupied wintering sites were in urban areas that were isolated from other sites. Three sites included abandoned rice fields, and another three sites were maintained as urban ecology parks, suggesting these environments are useful for the wintering warblers. In this study, the Japanese Marsh Warblers were observed in various types of reedbed, suggesting that wintering warblers can use more varieties of vegetation structure than was previously expected.

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Japanese White Eyes Zosterops japonicus were observed foraging on the nectar of Golden Trumpet Trees Tabebuia chrysotricha in Okinawa Island. Rather than accessing nectar from the opening of the flower, the white-eyes mainly robbed nectar by creating a hole at the base of the flower. They probably robbed nectar because their bills were too short to reach deeply into the long flowers. They perched on branches as they foraged, which also hindered them from getting at nectar from the opening of the flower. They did not appear proficient at hovering in flight, which would have allowed them better access to the flower opening.Robbing behavior included two methods. One was to insert the bill between petal and calyx. The other was to tear the petals. The latter type seemed to allow the reproductive organs to touch the bird's bill, which may assist pollination. In both maximum and average values, sugar concentration of Golden Trumpet Tree was higher than either Hibiscus Hibiscus rosa-sinens or Taiwan Cherry Cerasus campanulata. Golden Trumpet Tree would appear to be a potentially important food resource, but naturally-occurring naphthoquinone and phenolic glycoside may cause white-eyes to avoid this plant. Although the nectar robbing was frequently observed in 2011, we saw no case in 2012, 2013 and 2014.

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We recorded the songs of a Chestnut-winged Cuckoo Clamator coromandus at Hegura Island in Wajima City, Ishikawa Prefecture, Japan, on 20 May 2012. This is the first audio record and report of Chestnut-winged Cuckoo songs in Japan. The species was identified by comparing the sound spectrogram with the spectrograms of other confirmed Chestnut-winged Cuckoo recordings, and also by comparison with that of a similar species, the Moustached Hawk-cuckoo Hierococcyx vagans

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I studied the occurrence and habitat characteristics of Japanese Marsh Warblers Locustella pryeri wintering in southern Okayama Prefecture, conducted by seasonal observations from March 2014 to April 2016. I studied three reedbed sites: a former salt farm area called Kinkai, the shore of Kojima Lake, and the mouth of the Kurashiki River. I carried out the study using fixed-point observation with or without a call playback method. Warblers were recorded from late November to mid-April, and also recorded as they sang spontaneously, without making flight displays, from late March to Mid-April. Without flight displays, the birds were considered to be present as wintering and not as breeding birds. During the 33 total survey events between late March 2014 to mid-April 2016, 17 surveys resulted in positive detections of the species, and each detection ranged from one to three warblers. The characteristic vegetation of the occupied habitat was reedbed with an undergrowth such as sedge. The reed height was 1.9 to 2.2m, and the density of reeds was 48 to 58 stalks /m2. This study suggests that southern Okayama Prefecture has possibly been used regularly as a wintering site by Japanese Marsh Warblers.

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To discriminate between the two subspecies of the Ashy Minivet (Pericrocotus divaricatus tegimae and P. d. divaricatus), we used spectrograms to compare acoustic features between subspecific songs. Seven factors of a typical song phrase were assessed for each subspecies (P. d. tegimae n=17; P. d. divaricatus n=13). The factors included the following parameters: a) frequency (Hz) of the introductory part, b) frequency of the first peak, c) highest frequency of the phrase, d) frequency of the last peak, e) the duration of the phrase, f) the frequency at the maximum value of power spectrum, and a combination of b) and d). The average value for each parameter was calculated for each subspecies. Five frequency factors of P. d. tegimae were significantly higher than those of P. d. divaricatus. P. d. tegimae tended to sing flatly or in a falling tone, whereas P. d. divaricatus sang in a rising tone. In order to discriminate the two subspecies, we used two methods. For each spectrogram, we utilized a linear discriminant function, and we compared one of the measurable values and the 95% confidence intervals of that factor. Even when the focal acoustic files had been recorded under some unfavorable conditions, our methods were able to discriminate reasonably well between the two subspecies of Ashy Minivet. Using these methods, all four samples of unknown subspecies which were recorded in Kanagawa Prefecture were identified as P. d. tegimae.

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Citizen science approaches can result in larger data sets than studies conducted by individuals. However, it has the risks of errors and quality bias. To overcome these demerits of citizen science, we implemented a study of barn swallows Hirundo rustica, a well-known and well-regarded Japanese bird that frequently nests in railroad stations. The railroad stations are ideal survey sites for the citizen science approach because they inherently avoid several potential source of errors, including geographic bias and dissimilar conditions. Railroad stations enhance citizen science because 1) they include many locations from urbanized to rural landscapes, with appropriate distance intervals across several regions, 2) they have similar small-scale environmental conditions, consisting of open concrete buildings, and 3) they are easily accessible by the general populace of potential citizen scientists. In this study, assisted by 124 citizen scientists, we conducted a survey of nesting barn swallows in the Kinki District, which included six prefectures in south-central Japan. The data was collected from 1336 railroad stations between the dates of 16 May to 22 July, 2012. We posted all the nesting records as open data in the Creative Commons, license CC-BY 4.0 International. Data download: http://www.bird-research.jp/appendix/br12/12r01.zip

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