Tomohiro Ichinose

Urbanization and its implications for avian aggression: a case study of urban black kites ( Milvus migrans ) along Sagami Bay in Japan

Urbanization has caused countless changes in the lives, behaviors, and community structures of wild animals. Habitat loss in urban areas has led to the proliferation of certain species over others; in the case of birds, frugivores and certain predators can be found in abundance in cities. These birds, however, occasionally show novel behaviors that can cause stress within human-wildlife interactions. The black kite, Milvus migrans, for example, has displayed a tendency to attack humans for their food in certain urban areas in Japan. In order to determine how habitat availability and land-use types affected these aggressive tendencies, field observations were combined with GIS analysis of five locations along Sagami Bay in Japan. The following locations were assessed according to the amount of each land-use type present and the aggressive tendencies of each location’s black kite population: Enoshima, Fujisawa; Kamakura Beach, Kamakura; Zushi Beach, Zushi; Oiso Beach, Oiso; and Iwa Beach, Manazuru. The aggression of each population, designated by the log of the aggression index, was found to be significantly affected by the amount of forest area per black kite, the amount of non-rice-paddy agricultural area per black kite, and the season. Thus, aggression was higher amongst populations with less forested or agricultural area within their foraging zones, and aggression increased during spring, which is the breeding season.

Land-use change and irrigation systems in the agricultural landscape of terraced paddy fields in Awaji Island, central Japan

We analyzed changes in land use from 1963 to 2000 in the northern part of Awaji Island in central Japan, using topographical maps and aerial photographs. We compared these changes between two different irrigation systems: tazu, in which a community group jointly owns the rights to a water source, and private management. The study area consisted of 57.3% paddy field, 22.2% woodland, 7.2% urban land use, 6.3% grassland, 5.8% water body, and 1.2% dry field in 1963. In 2000, the area consisted of 44.3% paddy field, 21.0% woodland, 12.6% urban land use, 11.6% grassland, 5.3% water body, and 5.0% dry field. The proportion of agricultural use had decreased markedly over the 37-year period. In the tazu area, 38.1 and 37.7% of former paddy field had changed into urban land use and grassland, respectively, and 19.3% of former paddy field had become dry field by 2000. In contrast, 30.6% of former rice paddy had become dry field in the private management area. About half of the former rice paddy had changed into grassland (26.3%) and urban land use (24.0%) in the private area, and 18.6% had become woodland in 2000. In the tazu area, there were fewer abandoned fields, because farmers still manage their fields according to strict regulations. In the private management area, the set-aside or abandoned fields had changed into woodlands as a result of vegetation succession, because farmers had abandoned fields located far from their homes or on steep slopes. These results suggest that the irrigation system may influence the pattern of change in land use.

Relationship in Species Composition between Vegetation and Bird Communities in Remnant Woodlots on the Musashino Uplands and Sayama Hills

樹林地内部の植生の種組成が鳥類の分布にどのような影響を及ぼしているか明らかにするために, 武蔵野台地および狭山丘陵に位置する比較的規模の大きな樹林地において, 鳥類の分布と植生の種組成の対応関係を調査した。 それぞれの樹林地に植生の異なる複数の調査地点を設定し, 1994年の繁殖期に鳥類の個体数調査を行った。 その鳥類調査地点内に方形区を設定し植生を調査した。 調査結果から, 樹林性の種の中には, ヤブサメやメジロのように, 常緑樹林への遷移が進行している二次林を特に好む種があることが明らかになった。 また, 林床植生の貧弱な二次林には, 草地や疎林の環境に現れる鳥類が侵入することが示された。

Prey Items Delivered to Young Northern Goshawks Accipiter gentilis by a Single Pair Breeding in Central Tokyo, Japan

Abstract We examined the diet of young Northern Goshawks Accipiter gentilis before and after fledging through the direct observation of prey items delivered by a single pair breeding in central Tokyo. Observations were conducted from 13 May to 14 August 2015. Three hundred prey items primarily belonging to five bird species and two genera of mammals were recorded both before and after fledging. The species contributing most to the total diet were White-cheeked Starling Spodiopsar cineraceus and Feral Pigeon Columba livia, with pigeons contributing most to total biomass followed by White-cheeked Starling. Prey item composition differed between the periods before and after fledging. After fledging, the contribution of White-cheeked Starling to the diet decreased, whereas that of pigeon increased.

Green Infrastructure in Reconstruction After the 2011 Earthquake and Tsunami: A Case Study of Historical Change on Awaji Island in Japan

The magnitude 9.0 earthquake that struck the northwestern Pacific Ocean off Japan on 11 March 2011 and the subsequent tsunami wrought massive destruction and reawakened Japan to the importance of green infrastructure.

Factors Affecting Breeding-Site Selection of Northern Goshawks at Two Spatial Scales in Urbanized Areas

Abstract We determined breeding-site selection of Northern Goshawks (Accipiter gentilis) by comparing 33 breeding sites to 40 nonbreeding sites at the small (nest tree and vegetation structure within an 11.3-m radius of the nest) and the large scale (biomass of prey species and landscape structure within a 500-m radius from the nest) in the urbanized area of Kanagawa Prefecture, Japan. Goshawks selected primarily Japanese cedar (Cryptomeria japonica) trees over 50-cm diameter at breast height (DBH) as nest trees. Trees smaller than 35-cm DBH were avoided. We used univariate logistic regression to assess vegetation structure of the nesting area. At the small scale, canopy trees in the nest plots were larger and taller, with more canopy cover, than those in non-nesting plots, and nests were farther from human habitations. In addition, nest plots had fewer understory trees than non-nest plots. In multivariate logistic regression, the DBH of canopy trees, number of understory trees, and distance to human habitation were highest in importance. At the large scale, nest plots had a greater percentage of forest area, smaller percentage of built area, more forest edge facing open land, and more forest edge facing PCDRS (parks, cemeteries, developed land, recreational fields, and small-scale vegetated areas <0.01 km2 in a matrix of ≥30% residential areas). In the multivariate model, the length of forest edge facing open land and the percentage of built area were of highest importance.

Significance and limitations of the support policy for marginal hamlets in the strategy of self-sustaining regional sphere development

In Japan, less-favored areas known as “marginal hamlets” have multiplied rapidly, and the continuous care of such areas has been major problem for national land-use planning. This research aims to scrutinize how the positioning and directionality of the support for marginal hamlets are defined in the National Spatial Plan, the plan’s compatibility in solving the problems of a broad area and the requests from individual marginal hamlets, and the plan’s limitations. We conducted a field survey at Monzen town in Wajima City, Ishikawa Prefecture, and carried out the study’s purpose through a comparative analysis on the future image of bottom-up and top-down processes.

A Procedure of Compositional Data Analysis for Land Use Planning

Ecological analysis is essential for environmental assessment and planning. Based on ecological analysis we can recognize the ecological situation of the study area, and understand how environmental factors should be controlled to improve the ecological situation. Biological indicators have often been referred to in case of environmental evaluation. Various kinds of indicator organisms and methods have been proposed and practically used. For example, the simplest indicator is the number of species. But species richness can not always evaluate the quality of an area as a habitat appropriately. Especially in urban and suburban areas, species rich habitats are usually boundary habitats.