Farm ponds in Satoyama landscapes are important habitats for lentic organisms. However, there is concern about loss of biodiversity in these ponds owing to urbanization and/or abandonment. For conservation planning, species composition and diversity of the aquatic biota should be determined in each pond because of inter-pond differences. We investigated the aquatic fauna in 50 farm ponds in eastern and northern Harima, Hyogo Prefecture, between the 1st and 6th of August 2012. Using a cast net and a D-flame net, we captured 2,146 fish (representing 4 orders, 7 families, and 16 genera or species), and 154 invasive red-swamp crayfish (Procambarus clarkii) in the littoral zones of the selected ponds. The average number of fish species, individual fish and individual crayfish captured per pond, and the range in number between ponds was 3.0; 0-7, 43.0; 0-187, and 6.7; 0-54, respectively. We also measured the total biomass (g) of captured crucian carp (Carassius spp.), invasive largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), and red-swamp crayfish. The average biomass per pond, and the range in biomass between ponds was 221.9; 1.4-2,095.0 g (crucian carp), 116.6; 8.0-390.0 g (largemouth bass), 114.7; 1.0-690.0 g (bluegill), and 92.4; 0.2-760.0 g (crayfish). We suggest that these datasets may be useful for regional aquatic fauna conservation planning and for future academic research on the assemblage structureing assemblages of aquatic organisms.
For the management of the relationship between wildlife and society, we are required to know diverse socio-cultural values regarding the natural environment. However, conventional survey methods have two major problems. First, they need detailed preliminary information of human-nature relationships, such as subsistence activity, folklore, history, and the ecosystem. Second, a detailed survey is difficult to conduct a spatially explicit analysis for a wide area, such as that involved at a municipal level.
In this study, we conducted an analysis of a citizen participation survey project at Lake Mikatagoko, in Fukui Prefecture, central Japan, called “The Painting by Children of the Past Waterscape Program”. From this, we developed a new survey method for diverse socio-cultural values regarding the natural environment, and this solved several conventional problems.
The method for this case obtained basic spatially explicit information for diverse socio-cultural values regarding the natural environment on a municipal scale. In particular, it was important to analyze values that were strongly based on individuals, places and times. However, quantitatively analyzing, the utilization of the workshop and professionals' involvement were left as issues that needed to be addressed in order to develop better survey methods for diverse socio-cultural values.
In Japan, sika deer (Cervus nippon) cause serious agricultural damage. To reduce the damage, it is important to use fencing and to capture the deer causing the damage. Box traps are recommended for capturing deer around farms. However, there is little information about where to position the trip line to capture adult deer with a box trap. We determined the optimal position of the trip line where there was a high probability that a deer would be in contact with it. Three reared adult female deer were used to determine this, along with a mobile cage and polyester yarn as the box trap and the trip line, respectively. The height of the trip line was randomly changed between 20 cm to 90 cm at 10 cm intervals, while the distance of the trip line from the bait was positioned between 20 cm to 50 cm at 10 cm intervals. We investigated whether deer made contact with the trip line at each position. The relationships between trip line position and deer contact were analyzed using generalized linear mixed models. We found that trip line height significantly affected the deer contact. In contrast, the distance between the bait and the trip line did not affect the deer contact. The contact probabilities estimated by the best fitting model were high at trip line heights from 40 cm to 60 cm. In these positions, the deer contacted the trip line with their heads, necks, thoraxes, and backs.
In Japan, the Pallas's squirrel (Callosciurus erythraeus) is an invasive species with adverse effects on native ecosystems and urban human activities, and is becoming a serious concern. However, there remains a lack of knowledge about the basic ecological habits of Pallas's squirrels in urban areas. We conducted stable isotope analysis and GPS logger deployment to understand the diet and habitat use of Pallas's squirrels in Yokohama City, during summer. We found that the squirrels mainly foraged on plants from the small forests in the urban area, and most of their activities were carried out in the forest areas during summer. This suggested that the main habitat of the urban living squirrels are small forests in urban area. In addition, not very often, but some substantial movement of squirrels in human residential areas outside of the forest were observed in this study. Such behavior could be a potential factor for rapid dispersal of these invasive squirrels in urban areas.
Currently, several solar power plants have been constructed in wetland areas in Kushiro National Park without prior environmental impact assessment, as it was not required by the relevant laws in Japan. We surveyed abundance of individuals and egg sacs of the threatened Siberian salamander (Salamandrella keyserlingii) at a solar power plant site, prior to, during (2015-2016), and after (2017) its construction. We confirmed the presence of adults (n = 5 in 2015, n = 3 in 2016, and n = 1 in 2017), and metamorphs (n = 8, only in 2016) as well as egg sacs (n = 11 in 2015, n =37 in 2016, n = 36 in 2017) of this species during the survey period. For habitat conservation, we suggested the following measures to solar power producers: 1) installation of photovoltaic panels in the salamander's main habitat area should be avoided, and 2) the main habitats should be preserved as habitat “conservation area.” The solar power producers agree to implement our suggested conservation plan, and it was decided that we would monitor the salamander population– in this site for the next several years. We believe that this endeavor, supported jointly by producers and conservationists, sets a valuable precedent for the conservation of salamanders in areas with solar power plant construction.
Recording and storing the accurate location and the correct species names of roadkill is necessary when researches want to use roadkill data for analysis and countermeasures. Application program (apps) and websites can collect and store consistent, long-term and extensive data on target areas. Our object was to clarify issues by testing a trial app (roadkill observation system) which can create a database with photos and can search for species names of photos using AI for collecting roadkill data in Japan. Roadkill data were collected from September 2019 to February 2020 on Amami-Oshima Island. We evaluated the accuracy in two perspectives; the distance from roadkill location to the nearest road because compared to their positioning error, the accuracy of species names uploaded. Users input the correct species name for 66 uploaded images; however, six images were too unclear to identify by AI. The median distance from roadkill locations based on smartphone GPS to the nearest road was 3.0 m. Most GPS locations were within 20 m. Our trial of the roadkill observation system app would be effective for collecting roadkill data.