Japanese Journal of Conservation Ecology
Online ISSN : 2424-1431
Print ISSN : 1342-4327
Volume 28, Issue 1
Displaying 1-22 of 22 articles from this issue
Special Feature Endangered species conservation and ecotourism
  • Mitsuhiko Takahashi, Yuko Hayashi, Naoki Kikuchi
    2023 Volume 28 Issue 1 Article ID: 2232
    Published: July 05, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: July 05, 2023
    JOURNAL OPEN ACCESS

    Wildlife tourism is a significant part of ecotourism, which is an important sector in the hospitality industry. However, wildlife tourism presents several risks to conservation, especially because wildlife tourists favour the viewing of rare and endan-gered species. The special edition 'Endangered species and ecotourism' consists of four papers. Hayashi (2023) describes tourism activities that target the Blakiston's fish owl, Ketupa blakistoni, in Shiretoko, Hokkaido. Hayashi identified several risks to the recovery of owl populations due to pressure from birdwatchers, cameramen and lodges. Kikuchi (2023) studied owl tourism in Shiretoko and found that local stakeholders' views were not significantly different from those of conservationists. Kikuchi argues that conservation policies should incorporate multiple interests and pursue a reciprocal goal through capacity building. Okahisa (2023) focused on the crested ibis, Nipponia nippon, on Sado Island, by analysing the risks presented by birdwatching-tourists in comparison to the economic benefits. Okahisa found that birdwatchers bring significant economic benefits to the island, while the risks could be minimised by strictly observing certain recommendations, such as visitors keeping an appropriate distance from the birds. Takahashi (2023) outlines the Japanese laws used to regulate wildlife viewing and photography. Several statutes provide a means to regulate certain wildlife-viewing activities in protected areas; however, Takahashi concludes that these laws are weak or lacking, especially in relation to the protection of endangered species and breeding wildlife.

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  • Yuko Hayashi
    2022 Volume 28 Issue 1 Article ID: 2036
    Published: April 15, 2022
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 15, 2022
    JOURNAL OPEN ACCESS
    Supplementary material

    Organized by the government and conducted by a group of professionals, conservation programs for endangered Blakiston's fish owls Ketupa blakistoni have been underway since 1984. The government has kept habitat information and the location of owls undisclosed to prevent human disturbance, especially from bird watchers and photographers. However, intruders who seek to see and photograph this rare species have increased in number in some accessible habitats, with upsurges in the 2010s. Moreover, some private lodges have been feeding owls to facilitate visitor photographs. An internet search for personal blogs showing photographs of wild Blakiston's fish owls revealed that 47.4% of the blog pictures from specified locations were taken from lodges where it had been announced that owls could be seen. Three of the four lodges were feeding owls, and the remaining one was helping visitors to see owls feeding and nesting in the national forest surrounding the lodge. On Instagram, photograph location was stated for 55.1% of pictures and all of these were taken at lodges where owls were being fed. Eighty-seven percent of the blog photographs were shot at night, either using strobe photography or making use of lighting fixtures installed by the lodges. Of the 12.7% of daytime photographs taken under natural light, 32.9% were of immature fledglings and parent birds on the alert for intruders. Photographers who visited wild owl habitats were significantly older and male-biased compared to participants in guided zoo tours designed to watch and learn about Blakiston’s fish owls in captivity. Awareness of owl conservation projects also differed between the two groups, i.e., those who visited habitats were more knowledgeable about conservation measures for wild individuals than were guided zoo tour participants but less knowledgeable about efforts being undertaken in captivity. Furthermore, while photographers thought that their actions related to photography and birdwatching had a minor impact on owls, guided zoo tour participants had the opposite view. In particular, feeding was considered to have a negative impact on the conservation of Blakiston's fish owls by 86.3% of guided zoo tour participants compared to only 25% of photographers. This study revealed five problems with the current tourism uses of Blakiston's fish owls that need addressing: 1) disclosure of habitat information, 2) feeding owls as a tourism attraction, 3) use of artificial lighting, 4) acclimation to human and artificial conditions, 5) discordance with national conservation projects.

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  • Naoki Kikuchi
    2022 Volume 28 Issue 1 Article ID: 2035
    Published: August 03, 2022
    Released on J-STAGE: September 05, 2023
    Advance online publication: August 03, 2022
    JOURNAL OPEN ACCESS

    Allocation of local revenues from birdwatching to conservation projects can incentivize conservation of endemic bird species and other wildlife. However, nature tourism can also negatively affect target species and their habitats. In 1984, as part of a project to protect Blakiston's fish owl on the Shiretoko Peninsula of Hokkaido, the Japanese government purposely refrained from disclosing the owl's habitat to the public. However, lodging facilities on the Shiretoko Peninsula have begun to distribute owl feed to allow their guests to observe and photograph these rare birds. This practice has led to widespread dissemination of information on the owl's habitat, prompting concerns that conservation efforts may be adversely affected. As a countermeasure, conservationists have proposed a "show and protect" policy. The first step of this policy is to gradually reduce and eventually eliminate all artificial feeding so that the owl can be observed in more natural settings. The second step is to discourage any activities that will detract from the global and local value of the Shiretoko region. The third step is to provide an educational framework for people to learn about Blakiston's fish owl and its conservation. Implementing this conservation policy requires cooperation and consensus building among a diverse group of people, including local residents, members of the tourism industry, tourists, researchers, and government officials. In this study, to better understand the views of the public on the proposed policy, we conducted interviews with members of the local community, who will play important roles. The survey results indicate that there are no significant inconsistencies between the goals of the conservation policies and the views of local stakeholders. However, these groups differed in their perceptions of the natural environment, local community life, nature conservation initiatives, and profitable nature use. For this "show and protect" conservation policy to be effective, rules must be established in a creative and flexible manner to facilitate collaboration among people with diverse perspectives. The main challenges to this goal are recognizing a plurality of values, mutual acceptance of different objectives, and consensus building among stakeholders.

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  • Yuji Okahisa
    2021 Volume 28 Issue 1 Article ID: 2034
    Published: August 31, 2021
    Released on J-STAGE: September 05, 2023
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS

    Birdwatching tourism is presumed to contribute to conservation programs for endangered species by providing tourists with opportunities to learn about conservation activities and by improving economic incentives. However, it is important to evaluate and manage the negative impacts of tourism on the target species. The crested ibis Nipponia nippon became extinct in the wild in 1980s, although efforts towards its reintroduction to Japan are ongoing. In this study, I assessed the flight-initiation distances, vigilance, and fecundity of wild crested ibises, and evaluated the economic ripple effects of tourism on the regional economy and ibis conservation programs based on literature published before extinction. When foraging crested ibises were approaching by cars, the maximum flight-initiation distance was 145 m; the average distance decreased from 106.9 m in 2015 to 62.5 m in 2019. Crested ibis vigilance behaviour increased with vehicle approach, but was reduced when the flock size was large. For solitary birds, vigilance increased at a distance of 184 m, but when ibises were in a flock of five, vigilance increased at a distance of 128 m. Based on literature published before extinction, ibis fecundity significantly increased with restricted access to nest sites in forests. An estimated 52,902 tourists visited Sado Island annually to see crested ibises. From an economic input-output table, the economic contribution of the ibis through tourism was estimated to be 4.45 billion yen. The ripple effects on agriculture, forestry, and fisheries, which play important roles in preserving crested ibis habitat, were approximately 34 million yen; tourists donated approximately 16 million yen to Toki Forest Park. Based on these results, I make recommendations regarding ibis tourism. First, flocks of crested ibis in paddy fields should be observed from a minimum distance of 150 m and solitary birds should not be approached. Second, tourists should be prohibited from observing nesting ibises. Finally, a system should be developed to share the profits from ibis tourism with those engaged in agricultural, forestry, fishery, and conservation activities. The information presented here will help to promoting sustainable conservation activities for the crested ibis.

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  • Mitsuhiko Takahashi
    2022 Volume 28 Issue 1 Article ID: 2037
    Published: October 20, 2022
    Released on J-STAGE: September 05, 2023
    Advance online publication: October 20, 2022
    JOURNAL OPEN ACCESS

    Wildlife viewing and photography are activities to be encouraged, both for conservation and economic reasons. The number of people participating in wildlife viewing and photography is increasing, and their economic potential is high. However, wildlife viewing and photography can have negative effects, including disturbing nesting habitats or feeding behaviours. Thus, various entities have facilitated education and introduced codes of ethics or conduct to deter negative actions. These voluntary regulations are beneficial but lack enforceability, which only legal regulations can provide. Japanese statutes do not contain comprehensive provisions for regulating wildlife viewing and photography. Several statutes give the Minister of the Environment the power to restrict certain wildlife-viewing activities in limited protected areas; however, the administrative rules necessary for the agencies to enforce such restrictions have not yet been developed. The United States also lacks comprehensive statutes to regulate wildlife viewing and photography, although the Endangered Species Act prohibits the "take" of listed species, which includes "harass" by definition. In the United Kingdom, disturbing nesting birds is prohibited by law, and a licensing system allows photographers to photograph birds in nesting environments. It is necessary to urge Japanese agencies to exercise their legal powers, including promulgation of administrative rules. Furthermore, for the sound development of sustainable wildlife viewing and wildlife tourism, national and local lawmakers must strengthen laws to regulate them, especially in relation to the protection of endangered species and breeding wildlife, as well as the management of protected areas.

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Original Article
  • Yusuke Ueno, Kento Eguchi
    2023 Volume 28 Issue 1 Article ID: 2218
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS
    Supplementary material

    The Internet trade of rare species is a pressing issue worldwide. Small salamanders are among the taxa whose local populations have been threatened by collection. As of February 2022, 45 small salamander species have been recorded in Japan, of which 42 are listed in the Red Data Book 2020 of the Ministry of the Environment. Recent taxonomic research has recognised local populations in various regions as new species. Most species gather in small breeding ponds in the mountains and spawn in groups, a habit that exposes the adults, eggs, and larvae to the risk of mass collection. In this study, we focused on Internet auc- tions in Japan, where customer-to-customer trade (C2C trade) is very active, to investigate the trade status of small salamanders and identify some of the issues related to the trade of rare wildlife species. We used a comprehensive archive of transactions (including product name, price, bid date, product image and description, etc.) from Internet auction sites in Japan; the sites either provide information free of charge or are run by companies that charge a fee. We examined small living salamanders listed and sold in the "Pets and Creatures" category of auction sites from January 2011 to December 2020. There were 4,105 confirmed transactions (total value of successful bids: 14,977,021 JPY) for 28 species over the past 10 years on one of Japan's largest auction sites. The most transactions per species was for the clouded salamander Hynobius nebulosus (962 transactions), which is listed as endangered in the Red Data Book (Category IB [EN] or II [VU]), followed in order by the Japanese Black salamander H. nigrescens, Hida salamander H. kimurae, and Ezo salamander H. retardatus. Initially, the total number of transactions for small salamanders was around 200 per year, but has increased dramatically in recent years, exceeding 1,117 in 2020 (with the success- ful bids totalling 5,282,518 JPY in that year). This rapid increase was due to a few individuals who frequently advertise on the Internet. In addition, the number of transactions of those species more than doubled after cryptic species were described as new species in taxonomic studies. Therefore, immediate action is required to preserve local salamander populations. The method used in this study can be easily applied to survey trades involving other plants and animals.

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  • Sakiko Orito, Takashi Masaki, Takashi Kamijo
    2023 Volume 28 Issue 1 Article ID: 2222
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS
    Supplementary material

    Biodiversity provides a foundation for the cultural value and ecosystem services of plants in urban forests. Although urban forests in Japan differ from those in well-studied montane areas in many ways (e.g. fragmentation by artificial elements), conifer plantations remain major components. Birds play important roles in urban forests, providing pest control and contributing to plant reproduction through seed dispersal. However, the effects of fruit availability and forest and landscape structures on bird community composition have not been studied in conifer plantations in urban forests. Therefore, we investigated the extent to which birds use conifer plantations as habitat in an urban landscape and how stand structure, landscape configuration, and fruit availability affect the local abundance and species richness of birds. We compared the effects among different bird species and considered conservation strategies to promote bird diversity in urban forests. We established 18 study sites in Tsukuba, Ibaraki Prefecture, Japan: six plantations consisting only of conifer trees (denoted 'plantation') and 12 consisting of conifers mixed with broadleaf trees (denoted 'mixed forest'). At each site, we conducted 27 15-minute bird censuses just after dawn during January - November 2021. The basal area (BA) and mean diameter at breast height (DBH) of the trees at each site and the areas and edge lengths of forests within a 200-m radius around each site were considered variables that might influence local bird communities. In total, 27 bird species were recorded, and the six most abundant species were analysed. We categorised the 27 species into six functional groups in terms of body length and fruit preference. Habitat-selection analysis revealed that most functional groups and species were significantly more abundant and species richness was greater in mixed forests than in plantations. A binomial mixture model showed that the forest area around a site had a positive effect on most functional groups and species, whereas BA and the forest-edge length around a site had negative effects on some. DBH had either positive (e.g. Japanese pygmy wood- pecker, Yungipicus kizuki) or negative (e.g. long-tailed tit, Aegithalos caudatus) effects, depending on the functional group and species. Fruit availability had no significant effect on any functional group or species. These results imply that, to conserve bird community diversity it is important to maintain large non-fragmented forests in urban spaces. It would also be effective to increase the complexity of conifer plantations in terms of their local structure (e.g. mixture of broadleaf trees) and spatial heterogeneity (e.g. mosaic of young and old stands).

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  • Kie Morita, Takumi Akasaka, Masahiro Toyama
    2023 Volume 28 Issue 1 Article ID: 2131
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS
    Supplementary material

    In abandoned farmland, forests expand rapidly through natural regeneration. To design sustainable and effective biodi- versity conservation plans, both remnant and regenerated forests on abandoned land are being considered as candidate conserva- tion sites, based on the habitat preferences of conservation target species. However, the habitat requirements of forest-dwelling bird species vary according to landscape features and local environmental conditions, some of which are covariates. In this study, to provide data for owl-habitat conservation in forest management, we clarified the relative influences of forest area, fragmenta- tion, and quality on the distribution of the ural owl (Strix uralensis). A playback survey was conducted in 59 forest patches from July to September 2020 and in April 2021 on the Tokachi Plain in Central Hokkaido, Japan. Ural owl distribution was correlated positively with broadleaf forest area (i.e., habitat area) and maximum forest age (i.e., site-scale environment) and negatively with the number of riparian forest patches (i.e., habitat spatial configuration). Broadleaf forest area made the greatest single contribu- tion to distribution, whereas the number of riparian forest patches represented a very small contribution. In addition, forest area and age comprised a large common contribution. Our results imply that the amount of habitat is more important to ural owl distribution than spatial configuration of habitat. To increase habitat area for the ural owl, which is sensitive to forest fragmenta-tion, future conservation efforts should focus on broadleaf-tree regeneration in abandoned farmland from surrounding mature and remnant forests.

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Review
  • Dai Koide, Shohei Tsujimoto, Naoki Kumagai, Makihiko Ikegami, Jun Nish ...
    2023 Volume 28 Issue 1 Article ID: 2217
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS

    Anthropogenic disturbances and climate change have caused multi-dimensional changes in biodiversity and, conse- quently, in ecosystem services. In this changing world, citizen science and monitoring are essential ways to observe species’ spatiotemporal distributions and enhance, simultaneously, public awareness of biodiversity. Recent technological innovations have provided several digital platforms for citizen science using personal digital devices, but these platforms and the data-induced improvement in citizen observation programs have not been discussed. This paper compared three main platforms in Japan (iNaturalist, "Ikimono-log", and Biome) and discussed possible solutions to general challenges that citizen science has faced through data analyses. The three platforms differ in the applicable data type, usability, policy for data-opening, etc. Monitoring project organisers should understand the characteristics of each platform and select a suitable one. The main challenges for citizen science were data quality and quantity, such as species identification, spatiotemporal data bias and the shortage of specific data (e.g. the northern/southern limits of distributions and phenology data). There were also problems with project management, such as limited communication with participants and the continuity of each project. The accuracy of species identification has increased by using artificial intelligence and photographs of observed species with location information. Solutions for other challenges, such as the spatiotemporal data bias and shortage of specific data, should be developed by using and analysing stacked observation data. Visualisation of observed data for each species, model predictions filling the spatiotemporal gaps in observations and con- tribution reports for each observed dataset should be useful for solving these data collection challenges. Sharing real-world ob- servation data broadens analyses in the digital world, and the results should be shown on participants’ devices as a way to improve their observations and further their enjoyment in making observations, which would improve the model analyses. Creating an observation system targeting this desirable circulation between the real and digital worlds should motivate citizen science further, enhancing the connectivity of a nature-friendly society.

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  • Gen Ito, Jyun-ichi Kitamura, Rintaro Taniguchi, Masahiro Kumagai
    2023 Volume 28 Issue 1 Article ID: 2205
    Published: July 05, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: July 05, 2023
    JOURNAL OPEN ACCESS

    Bitterlings (subfamily Acheilognathinae) are a group of small cyprinid fish, comprising 16 taxa (11 species and 8 sub-species) distributed in Japan, where all bitterling taxa are endangered. Because bitterlings are popular as pets and fishing targets due to their attractive and diverse nuptial colouration, they have been released deliberately in various regions, even outside of their native ranges. Therefore, many Japanese bitterling populations are recognised as domestic alien fishes that pose a major threat to native bitterling populations. In this study, we summarise comprehensively the geographical distribution, control and eradication attempts, and establishment status of domestic alien bitterling populations based on the literature. Our results showed domestic alien distribution in 14 bitterling taxa. Acheilognathus cyanostigma has been recorded as a domestic alien species in 19 prefectures, and Acheilognathus rhombeus, Acheilognathus tabira tabira, Tanakia lanceolata, and Tanakia limbata have been recorded as domestic alien species in more than 10 prefectures. Notably, there have been many invasions in the Tohoku region, which is inhabited by few native bitterling species. No records of projects to control or eradicate domestic alien populations were found. We discuss the possibility of naturalisation in both channels and still waters, as well as hindering pathways toward their introduction outside of their native ranges, based on the naturalisation records summarised in this study.

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Report
  • Haruka Ukita, Nozomu Sato, Takeshi Osawa
    2023 Volume 28 Issue 1 Article ID: 2219
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS
    Supplementary material

    Luciola cruciata is a common firefly species that has cultural significance in Japan, and it is often reintroduced in regions where its numbers have diminished. It is therefore important to determine appropriate reintroduction and/or population-reinforcement strategies for the conservation of L. cruciata. In this study, we used historical land-cover data to evaluate the landscape conditions needed for the establishment or maintenance of L. cruciata populations. We surveyed the presence or absence of L. cruciata in the southern Tama region of Tokyo, and used a statistical model based on Akaike's information criterion (AIC) to analyse the association thereof with land-cover history. Among the parameters included in the model, only the presence of a current open-water area was positively correlated with the presence of L. cruciata (AIC = 271.11). A slightly lower AIC value (270.44) was obtained for a land-cover-history model that included current open-water area, 1980s' forest area, and 1960s' farmland area; all explanatory variables in the model were positively correlated with the presence of L. cruciata. The results imply that the suc- cess of reintroduction and/or reinforcement of L. cruciata populations may depend on the land-cover history. The findings of this study will be helpful for identifying regions suitable for establishing or maintaining L. cruciata populations, which is important for the conservation of this species in Japan.

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  • Takahiro Morosawa, Tomiji Hagiwara, Masahiro Kumagai, Satoshi Arai, To ...
    2023 Volume 28 Issue 1 Article ID: 2213
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS

    An event-based, participatory citizen monitoring program called "One-day Fisherman's Experience" was conducted in Kasumigaura, Japan. The participants utilized set-net fishing, and examined and ate their catch. This monthly event occurred 142 times from April 2006 to January 2020; 2,177 people participated, with about 20 individuals in attendance at each event. The results of the monitoring revealed that native species, such as Salangichthys microdon, Opsariichthys platypus, Hyporhamphus intermedius, Acanthogobius lactipes, Acanthogobius flavimanus, and Gymnogobius castaneus, first decreased and then increased in number. Bitterlings, Ministry of the Environment's Red List species, were not caught after 2009. Information on alien species abundance was determined. The presence of Megalobrama amblycephala, a species from outside Japan, was confirmed in 2018 and Biwia zezera, a domestic alien species, first appeared in 2013. The last observation of Mylopharyngodon piceus and Odontesthes bonariensis was in 2010. These results suggest that public participatory monitoring is useful for understanding pat- terns of native and non-native species, and for Red List species monitoring. As a limitation, the monitoring efforts were dis- rupted by the COVID-19 pandemic.

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  • Hideyuki Niwa
    2023 Volume 28 Issue 1 Article ID: 2207
    Published: July 05, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: July 05, 2023
    JOURNAL OPEN ACCESS

    Detailed information regarding the distribution of plant species in wetlands is important for wetland ecosystems manage-ment. Elevation gradients, major environmental factors that influence the spatial patterns of wetland vegetation, can be obtained at high resolution using light detection and ranging (LiDAR). In this study, we developed a new wetland habitat mapping technique that uses a high-resolution digital terrain model based on unmanned aerial vehicle (UAV)-mounted LiDAR data and information regarding the distributions of selected indicator plant species. The study site was a wetland around Omi Maiko Inland Lake in Otsu, Shiga Prefecture, Japan. A high-resolution digital terrain model with an absolute positioning accuracy of ± 5 cm was cre-ated using UAV-mounted LiDAR data collected in winter, when the aboveground parts of herbaceous plants were dead and de-ciduous trees had dropped their leaves. Five indicator plant species growing in mesic to submerged grasslands were selected; the relationships of these indicator species with elevation were analysed. Elevation differences among indicator species were used to create a vegetation zoning map based on classified microtopography and indicator species distribution. The results of this study provide basic information and a new technique for wetland ecosystem management.

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  • Seiki Takatsuki
    2023 Volume 28 Issue 1 Article ID: 2130
    Published: July 05, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: July 05, 2023
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    J-STAGE Data

    Seed dispersal by birds is important for conserving biodiversity in urban green space. Isolated trees in urban environ-ments with paved ground surfaces are suitable for collecting seeds, which is difficult in complex forests. The timing of fruiting of four tree species (Melia azedarach, Toxicodendron succedaneum, Ligustrum lucidum, and Ilex rotunda), their use by birds, seed delivery, and the relationships among the sizes of the fruit, seeds and bird bills were studied in Kodaira in western Tokyo, Japan, from December 2020 to March 2021. The timing of fruiting and seedfall synchronised in L. lucidum and T. succedaneum, while seedfall was delayed by 2 weeks in M. azedarach and 1 month in I. rotunda. Birds delivered seeds of 11-29 plants to the focal trees. The numbers of seeds recovered under the target trees ranged from 900 to 1300 seeds/m2, except for M. azedarach (-30 seeds/m2). The proportion of seeds delivered from elsewhere was 47.7% in M. azedarach and less than 20% for the other three species. The majority of fruits were smaller than 10 mm in diameter, which was smaller than the bill width of the brown-eared bulbul (Hypsipetes amaurotis, 15.4 mm), except for those of Trichosanthes cucumeroides and Neoachmandra japonica.

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  • Takaaki Hanai, Akira Nakanishi, Kuninori Ban, Shogo Hattori, Naoki Tag ...
    2023 Volume 28 Issue 1 Article ID: 2210
    Published: July 05, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: July 05, 2023
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    We examined the gastrointestinal contents of the Hotoke loach (Lefua echigonia) sampled throughout the four seasons at two sites in valley-bottom paddy fields in Aichi Prefecture, Japan. The highest number of individuals belonged to family Chironomidae, followed by class Copepoda and family Lepidostomatidae. Wet weight was highest in Chironomidae, followed by the families Erpobdellidae and Tipulidae. At both sites, the percent index of relative importance (%IRI) of Chironomidae samples was highest in Hotoke loach of standard length < 50 mm and lower in those with greater lengths (50-60 mm) that foraged primar-ily on heavier aquatic prey such as Erpobdellidae, Lepidostomatidae and Tipulidae. We detected a weak positive correlation be-tween loach standard length and maximum wet weight of prey. At both sites, Chironomidae had the highest %IRI among prey taxa in all seasons, except for June at Site B, and the %IRI of Chironomidae was higher in winter than in all other seasons. Although we did not investigate the abundance of benthic invertebrates or other Hotoke loach prey organisms at the sites, our results imply that the loach utilises chironomids year round, and especially in winter, such that it is highly dependent on this family. The findings of this study highlight the importance of conserving environments that are rich in chironomids, the main food resource of the Hotoke loach during the juvenile stage and in winter, and which provide a habitat for a variety of benthic organisms, including large aquatic invertebrates such as Erpobdellidae and Tipulidae.

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Practice Report
  • Nobuaki Ichijo
    2023 Volume 28 Issue 1 Article ID: 2121
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS

    Twenty mesh traps were set from spring to autumn every year from 2013 to 2015 to capture invasive crayfish (Pacifastacus leniusculus) in a small (820 m2) pond in Kushiro City, Japan. In total, 850 small crayfish (< 30 mm in carapace length), 471 medium-sized crayfish (30-39 mm in carapace length), and 80 large crayfish (>= 40 mm in carapace length were captured and killed. The numbers of captured individuals decreased from 1,205 in 2013 to 162 in 2014 and 34 in 2015. Between 2016 and 2020, crayfish were captured at least eight times each year. From June to September, there were 20 traps in the pond. However very few crayfish were captured (one in 2016, two in 2017, four in 2018, and seven in 2019). In 2020, 16 attempts were made to capture crayfish, but none was captured, although eradication has not yet been confirmed. Size-frequency data in 2013 were analyzed by sex each month. Groups I-IV represented small, small-to-medium, medium-to-large, and large crayfish respectively. In July, females of all groups were captured; males fell into groups I to III. Then, groups II, III, and IV disappeared, with (young) group I crayfish remaining from September. In 2014 and 2015, a few small and medium males and females were captured. Only two large males were captured in 2014 and one in 2015. No small individuals were captured from 2018 onwards. No medium or large individuals were captured in 2020. This study implies that Pacifastacus leniusculus in isolated small bodies of water can be eradicated by long-term trapping using large numbers of mesh crayfish traps.

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News
  • Asumo Kuroda, Naoyuki Nakahama, Daisuke Hayasaka, Masanori Tamaoki, Ta ...
    2023 Volume 28 Issue 1 Article ID: 2214
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS

    Spartina alterniflora Loisel., which is native to the Atlantic coast of North America and the Gulf Coast of Mexico, is a perennial grass that occurs on intertidal mudflats and in estuarine salt marshes. The distribution of this species is currently in- creasing worldwide owing to intentional introductions for conservation and management purposes (e.g. reclaiming tidal flats and protecting coastal areas) and/or via unintentional introduction pathways, including escape from managed sites. Spartina alterniflora affects native intertidal ecosystems and coastal industries by forming dense communities in areas where it has encroached. The species was first detected in Japan in 2008, in the vicinity of the Umeda River estuary in Toyohashi City, Aichi Prefecture. The species was also detected in Kumamoto Prefecture in 2010. Due to the threat that S. alterniflora may pose to intertidal eco- systems and coastal industries, all Spartina species, including S. alterniflora, were listed as invasive alien species by the Japanese government in 2014. Here, we summarise the morphological and ecological characteristics of S. alterniflora and report on a new population detected in an estuarine salt marsh in Shimonoseki City, Yamaguchi Prefecture, in 2020.

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Scientific Proposal
  • ResearchPropositionSubcommittee EcosystemManagementCommittee, Takaaki ...
    2023 Volume 28 Issue 1 Article ID: 2211
    Published: April 30, 2023
    Released on J-STAGE: September 05, 2023
    Advance online publication: April 30, 2023
    JOURNAL OPEN ACCESS

    Recently, Japan has faced social challenges that include a rapidly shrinking population, frequent natural disasters, the stagnation of local economies, and the COVID-19 pandemic. Simultaneously, growing social interest in sustainable development goals and biodiversity conservation has drawn attention to the relationship between corporate management and natural capital. In response, many administrative plans feature concepts related to addressing societal challenges by utilising natural resources and functions, such as green infrastructure, nature-based solutions (NbS), ecosystem-based disaster risk reduction (Eco-DRR), eco- system-based adaptation to climate change (EbA) and the Regional Circular and Ecological Sphere. By summarising domestic and international trends related to these concepts, The Committee for Ecosystem Management of the Ecological Society of Japan discussed key points for sustainable, effective utilisation of natural resources and functions from an ecological perspective and identified 12 points for practitioners and researchers involved in regional planning and project implementation to keep in mind when promoting green infrastructure/NbS. Two basic principles emphasise: "diversity and redundancy" and "regional and his- torical characteristics". Six points cover the characteristics of ecosystems: "the spatial scale of the ecosystem"; and the "changes and dynamics", "connectivity", "functions", and "linkage of ecosystem services"; and "uncertainties" of ecosystems. The remain- ing four points concern the relationships between management and socio-economy, and focus on "the state of governance", "impacts to the local economy and society", "relationship with international goals and related plans" and "education and dis- semination".

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