Changes in the hunting and trading of wild boar (Sus scrofa) and the distribution of traders in the Showa era between 1925 and 1989 were studied using two methods; the first was questionnaires which were sent to 419 branches of the Japan Hunters Association (JHA) in 34 prefectures, and the second was interviews with hunters and traders in 6 prefectures. Hunting big game, including wild boar, has become the most prevalent in recent decades. The most popular means for hunting wild boar since the 1920's has been to use guns and dogs. Wire leg traps have become wildespread recently. Harvested boars were currently being traded in 49.1% of the surveyed branches of the JHA. There were few prefectures in which broker or wholesale sales of wild boar meat were conducted before World War II (17.6% of the prefectures studied), but such sales have increased to include 67.6% of prefectures studied at present.

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Vertical distribution of the wintering sika deer (Cervus nippon) population, current food biomass, and the percent composition of sasa grass in rumen contents of sika deer at Mt. Tanzawa were surveyed to evaluate the importance of sasa as a main component of sika deer winter habitat. The results were as follows; 1) high density, 53.1/km^2, and extremely concentrated distribution of the sika deer population were observed in February with little snow cover around the top of Mt. Tanzawa, 2) Sasa hayatae which occurs above 1, 300m in elevation was the only food plant which had a high biomass in the study area, 3) relatively high composition of sasa tissues in winter rumen contents collected around Mt. Tanzawa indicated that deer fed on S. hayatae as a staple food. The reasons why high density and concentrated distribution of sika deer population occurred were that deer used habitat where highly resistance sasa species such as S. hayatae were prevelant, rather than areas where widely distributed species such as Pseudosasa purpurascens were undergoing retrogression, namely in areas below 1, 300m in elevation.

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Longterm changes in the population dynamics of sika deer (Cervus nippon) and suzutake (Pseudosasa purpurascens) were surveyed between 1972 and 1980 in the Tanzawa Mountains, central Honshu, Japan. The density of sika deer decreased from 47/km^2 in 1972 to 18/km^2 in 1979, in conjunction with a decrease in the area size of suzutake stands of less than 10 years of age which supply abundant forage for sika deer. The suzutake population, the main diet of sika deer in winter, retreated from the lower area of around 500m in elevation in 1973 to the higher area above 1, 070m in elevation in 1980. In addition, the amount of biomass at the top of the plants became extremely small during this period. Those changes were probably caused by heavy feeding pressure of the high sika deer density that was induced by the increase in area size of clear-cut forests during the period of 1963-1971. From the above, it could be asserted that clear-cut operations should be regulated in size and distribution for the stabilization of sika deer populations at a lower level density.

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Population densities of wild boars (Sus scrofa) and wolves (Canis lupus) for the 16 years between 1980 and 1995 in the Bieszczady Mountains, south-eastern Poland, were compared to evaluate possible effects of wolf predation on the dynamics of wild boar populations. The population trends of wolves (measured by the level of their harvest) and wild boars showed opposite trends with a significant negative relationship (r^2=0.611, p<0.001).

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