Recently, the red-crowned crane Grus japonensis occurring in eastern Hokkaido has expanded its habitat into farmlands from its original marsh habitat. We compared home range size, foraging habitat and the amount of food resources between the cranes inhabiting farmlands and those in marshlands. The home range sizes of the cranes in farmlands enlarged with the growth of their chicks, and consequently the cumulative home range sizes throughout the breeding period were larger in farmland-breeding pairs than in marshland-breeding pairs. As for foraging habitats, farmland-breeding pairs did not depend on wetland as much as marshland-breeding pairs and showed a tendency of shifting from wetland to artificial environment such as agricultural lands and cowsheds with the growth of their chicks. There was no remarkable difference in the total amount of food resources within a home range between farmland-breeding pairs and marshland-breeding pairs. However, food resource content differed between the two types: farmland-breeding pairs frequently ingested agricultural food such as dent corn, whereas marshland-breeding pairs ingested only natural food. The results suggest that stage-dependent and flexible expansion of home ranges and consequent acquisition of abundant food resources even in artificial environment enabled cranes to inhabit the farmland. If dependence on dent corn and artificial environment continues, it will increase risk such as ingestion of injurious substance and trouble with people and vehicles. Then, we suggest conservation measures for farmland-breeding cranes: (1) to keep cranes away from cowshed and road, (2) to create the habitat with abundant natural food at some distance from cowshed and road.

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Terrestrial soil erosion is a major factor that influences coral reef environments. We monitored changes in the amount of suspended particles in sea sediment (SPSS) every three months from August 2000 to May 2003 at 32 points on a coral reef at Shiraho, on the eastern coast of Ishigaki Island, Okinawa, Japan. The mean SPSS of all 32 points over the three years was 14.8 kg/m^3, and we found no significant differences among log SPSS values throughout the study period. The mean SPSS was highest near the coastline, followed by the center of the moat and the reef crest. The mean log SPSS was significantly greater in the Moriyama Channel, located northeast of the mouth of the Todoroki River, compared to other points near the reef crest. Four points north of the Todoroki River mouth, the main inflow source of the suspended substance, showed a mean SPSS of 50 kg/m^3 or more, suggesting influences of anthropogenic run-off that may have significant influences on coral reef ecosystems. There was no significant difference in mean SPSS among seasons in the entire moat. However, the mean SPSS at the four points north of the Todoroki River mouth was highest in autumn and tended to decrease toward the following summer. These observations and annual rainfall patterns suggest that major run-off events occur during late summer and autumn. The large amount of sedimentation in the area north of the Todoroki River mouth and the Moriyama channel indicates that topographical features of the moat influence the patterns of the suspended soil sedimentation, with a major supply from the river mouth and continuous outflow from the channel.

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In this article, we discuss the differences in biodiversity conservation policies between Japan and the United States, with a particular emphasis on ecological impact assessment, ecosystem restoration, conservation education, and public participation and collaboration for conservation practices. U. S. conservation policies have been developed over the last century on the premise that environmental decision-making is achieved through science, democratic conflicts, and collaborations. In Japan, on the other hand, the concept of biodiversity has only recently been introduced to the national administration sector during the last decade. As one of its important research tasks, conservation ecology in Japan must develop effective conservation education programs and communication skills to promote dissemination of ecological knowledge to the public and to better integrate ecological aspects into political decision-making and practices.

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In our earlier surveys of the Yancheng Nature Reserve in mid-December 2003, we overlooked the status of wintering Japanese (Red-crowned) Cranes, Grus japonensis Miiller, in China. Recently, many traditional wintering places of this species have disappeared because of land development in China. As a result, the cranes now gather in this reserve, particularly at its central part, which includes a core area that has been left as relatively natural wetlands. During our survey, 78.4% of 389 cranes were found in this central area, 4.1% in the north, and 17.5% in the south. Inner, somewhat dry, lands of the reserve are largely cultivated as paddy or wheat fields and coastal tidelands with shallow water have been transformed into huge salt fields and aquacultural ponds, which are usually drained for fishery harvesting in fall and winter. Even though these developments have not only brought economical benefits to local people but have also furnished a large amount of food for wintering cranes, they have also caused potentially serious problems for the Japanese crane population, including the destruction of natural wintering habitats, excessive habituation to humans, and concentration of the population in a small area. Therefore, we propose three countermeasures: reduction of wetland development, prohibition of human interference with cranes, and dispersion of small crane flocks in cooperation with local people.

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Conventional paddy farmland consolidation in Japan, which aims to increase farming efficiency by improving the drainage conditions of paddy fields and independently creating irrigation and drainage canals, is thought to have negative impacts on biodiversity in rural areas. The Land Improvement Act of Japan was amended in June 2001 and requires agricultural and rural development projects to be harmonized with the environment. It is widely recognized that transforming concrete irrigation and drainage canals into earthen canals and minimizing the differences in elevation between paddy plots and drainage canals aid in the preservation of aquatic animals. However, most paddy fields that have been consolidated using conventional standards will inevitably remain intact, thus continuing to have a substantial influence on the regional environment. Therefore, at least the minimum environmental measures should be effectively implemented in consolidated paddy fields. To this end, the distribution of the aquatic animals associated with these fields requires clarification. In addition, this knowledge will be useful in determining how to effectively distribute water during the non-irrigation season. The purpose of this study was to clarify the distribution of aquatic animals in the canal systems of main, lateral, and farm drains in the consolidated paddy fields, with a special focus on canal structure and year-round water flow in the canals. A field survey at six sites, which were selected for their different canal levels, was carried out in Shimodate City, Ibaraki Prefecture, Japan (36°21'N, 139°59'E). Sampling was conducted at monthly intervals from April 2001 to March 2002. A survey of fishes revealed that Zacco platypus (Oikawa) was concentrated in the main drains, while Misgurnus anguillicaudatus (Dojou) was found mainly in the lateral and farm drains. Among aquatic insects, Calopteryx atlata (Hagurotombo) was concentrated in the lateral drains, while Orthetrum albistyrum speciosum (Shiokaratombo) was observed primarily in the farm drains. Zacco platypus preferred gravel-bottom main drains to those made of concrete. Calopteryx atlata and Orthetrum albistyrum speciosum preferred year-round water flow to seasonal flow in lateral and farm drains, respectively. In contrast, Sympetrum infuscatum (Noshimetombo) preferred seasonal water flow to year-round flow in farm drains. The drainage systems in the consolidated paddy fields are clearly composed of different levels of drains with peculiar physical conditions, e.g., water depth and flow velocity, each of which attracts certain aquatic animals. To enrich the biodiversity of the paddy fields, our results suggest the importance of year-round water flow and natural materials for canal beds.

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To conserve the brackish water damselfly Mortonagrion hirosei, a reed community was artificially established adjacent to a small natural habitat in Mie Prefecture, Japan, in 2003. From April to November, we measured the dynamics of the reed community as well as the changes in abiotic factors in the understory of the community in which M. hirosei adults were active. Reeds that emerged in the artificial community were thinner and shorter than those in the natural habitat, however reed density did not differ between the two habitats. Therefore, the established reed community provided a more open habitat for M. hirosei adults compared to the natural habitat. Although adults of many odonate species were observed flying over both reed communities, only larvae of Ischnura senegalensis were collected in November in addition to those of M. hirosei. Because a predator of M. hirosei is I. senegalensis that should be excluded from the community, maintaining a dense reed community must be important for the conservation of M. hirosei.

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[in Japanese]

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[in Japanese]

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During the past several decades, an overabundance of sika deer has caused dramatic increases in agricultural and forestry damage, and has severely affected natural vegetation and ecosystems in many areas of Japan as a result of heavy foraging pressure. In national parks and nature reserves, where conservation of natural environments is the highest priority, managing overabundant deer is an imminent and major concern. Sika deer, which were once locally extirpated, re-colonized the Shiretoko Peninsula in the 1970's. The population has been increasing since the mid 1980's, resulting in chronic effects on the natural vegetation of forests and grasslands. Although severe climatic conditions and scarcity of food resources during the winter may regulate the deer population in Shiretoko National Park, the deer are able to sustain a high density due to the high female survival rate as well as a high intrinsic rate of increase. The population can be reduced only by heavy snowfalls that are severe enough to kill females. Therefore, natural processes alone are unable to alleviate the impacts of deer on vegetation. Unfortunately, from the currently available data, we cannot determine whether the irruption of sika deer in the NP is caused by socioeconomic activities or by ecological processes. It is imperative to establish a comprehensive management plan for sika deer that considers differences in land use status and conservation purposes both in Shiretoko NP and in peripheral areas. Also, vegetation monitoring is essential for evaluating the extinction risk of plant species and communities. If habitat restoration and population control of sika deer are to be implemented in and around the NP, these measures must be closely linked with deer and vegetation monitoring results to adaptively manage sika deer and ecosystems in Shiretoko NP.

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A number of members of the Ecological Society of Japan (ESJ) are concerned about the change in the ESJ standpoint from that of a pure-science oriented society to a conservation-oriented society. During the 51st Annual Meeting of the ESJ held in August 2004, the Standing Committee of the EJS organized a symposium entitled, "Where is the ESJ going?". Some members worried about conflicts between pure scientists and conservationists. Some panelists of the symposium questioned whether it is appropriate for the ESJ to write appeals for nature conservation. In 2000, the ESJ Committee for Natural Conservation distributed a memorandum that clarifies the conditions of procedures for sending appeals. However, this memorandum does not indicate which appeals are academically appropriate. The ESJ is not a pressure group for nature conservation, and we must acknowledge variety in the political standpoints of our members. In addition, I think the value of and scientific reasoning behind nature conservation are still unclear. Articles published in this journal are peer-reviewed by EJS members and other experts including pure scientists. It is important that (1) appeals by the EJS acknowledge the procedures rigorously outlined in the memorandum; and that (2) appeals by the EJS are peer-reviewed by all EJS members, including pure ecologists. Our journal welcomes any opinions that EJS members may have regarding this issue.

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