To ascertain the northern limit of dugong habitat, this study investigated the distribution of dugong and seagrass in the Tokara Islands (Nakanoshima and Takarajima) and Amami-Oshima, in the Ryukyu archipelago. No dugong habitat and seagrass was found in Nakanoshima and Takarajima. In view of the seashore landscapes of the Tokara Islands, dugong habitat was not established from Kuchinoshima to Takarajima. Four dugong sightings occurred at Kurosaki and Yanosaki, in Kasari Bay at Amami-Oshima. The fact that that witnesses were a fisherman and a diver adds credibility to the sightings. In addition, colonies of three species of seagrass (Halophila ovalis, Syringodium isoetifolium and Halodule uninervis) were observed in Kasari Bay, distributed over a large area of the bay. These findings suggest that dugong habitat is established around Kusari Bay, and therefore, that this bay is the northern limit of dugong habitat in the Ryukyu archipelago.

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Reedbeds along the lower Iwaki River, Aomori Prefecture are among the main breeding areas of the Japanese Marsh Warbler (Locustella pryeri), after Hotokenuma marsh, Aomori Prefecture and the lower Tone River, Ibaraki and Chiba Prefecture. For the past 30 years, the lower Iwaki River has been known as a breeding area of this endangerd species. People in this region utilize reeds and manage the reedbeds by cutting the stems in winter and burning some parts of the reedbed in spring. These human activities appear to create suitable habitat for the Japanese Marsh Warbler. Our investigation examined the relationship between reedbed management and breeding of the Japanese Marsh Warbler in 2002 and 2003. In spring, Japanese Marsh Warblers arrived at the breeding ground and settled in non-burnt areas where patches of dead reeds remained and some types of sedge had grown. These types of vegetation are necessary for breeding. In summer, the late breeding season, they dispersed gradually to burnt areas where new reeds had grown. The non-burnt areas were continuously used by large numbers of birds until the end of the breeding season. The burning of the reedbed was carried out in different areas in each year of the study, with the result that the territories of the Japanese Marsh Warbler shifted. This study clearly indicated the importance of non-burnt areas for breeding and suggested that reedbed management activities, such as burning of the reedbed to prevent vegetational succession, also contributed to the maintenance of breeding area of the Japanese Marsh Warbler.

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This study analyzed the chemical composition of seagrasses that are potentially eaten by dugongs (Dugong dugon) near Kayo Beach, Okinawa Island, and Kasari Bay, Amami Island, in southwestern Japan. The main seagrasses at Okinawa Island were Halophila ovalis, Halodule uninervis, Syringodium isoetifolium, Cymodocea rotundata, and Thalassia hemprichii, of which the most important were Halophila ovalis, Halodule uninervis and Cymodocea rotundata. At Okinawa Island, the crude protein content of Thalassia hemprichii and Cymodocea rotundata was higher than in other seagrasses, the neutral detergent fiber (NDF) content of Halodule uninervis and Cymodocea rotundata was higher than other seagrasses, and the cellular content (CC) of Halophila ovalis and Halodule uninervis was higher than of Syringodium isoetifolium and Thalassia hemprichii. The cell wall (CW) content showed an inverse relationship to CC. At Amami Island, the NDF content of Halophila ovalis was higher than that of other seagrasses, and the CC content of Halophila ovalis was higher than that of Halodule uninervis. The CW content showed an inverse relationship to CC. Halophila ovalis was found to have higher protein content at Amami Island than at Okinawa Island. This study indicated differences in content of protein and NDF for different growing area and species.

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Food selection of Japanese monkeys (Macaco fuscata) inhabiting areas near farmland was studied through fecal analysis, direct observation, and feeding-trace analysis methods, from December 1999 to November 2003 in Nishimeya Village, Aomori Prefecture, located in the northeastern Shirakami Mountains of Japan. The monkeys showed a preference for the bark of Morus bombycis in winter. When the snow was deep, they also fed on a wide variety of wild foods, such as waterweeds, bamboo grasses, mushrooms. In August, when their food resources in cool temperature forests are generally reduced, their feeding time in the forest (1.8 hours) was significantly shorter than on farmland (8.3 hours). The monkeys may be attracted to farmland for feeding, as farmers are not able to guard their land adequately due to the depopulation and aging of farming communities. Another peak period for monkeys to feed on farm crops is in November, when they supplement their intake of wild foods with waste apples, lying on and around farmland. This food selection may help to stabilize their food supply and store nutrition to enable them to survive the heavy snowfall season.

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We investigated the effectiveness of simple fences in preventing agricultural crop damage by the wild boar (Sus scrofa). The types of fences that farmers could install and maintain included simple electrical, wire net, and tin plate fences. Hardware and maintenance requirements were evaluated separately. Results revealed that the potential for preventing damage by wild animals was higher for simple electric fences than for tin plate fences. When properly maintained, simple electrical and wire net fences were the most effective. No damage by wild boars was observed in fields surrounded by simple electrical fences that were maintained properly. Both proper installation and maintenance are therefore important prerequisites for ensuring that simple electrical and wire net fences are effective at reducing agricultural damage by the wild boar.

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