Recent studies have shown that an increase in the population size of sika deer (Cervus nippon) decreases the abundance of rodents but increases that of several invertebrates (Scarabaeidae, Rhaphidophoridae, and earthworms) outside a deep-proof fence in Oku-Nikko, Japan. Therefore, the diet of red foxes (Vulpes vulpes) feeding on these animals is expected to vary according to changes in prey abundance. As red foxes also scavenge deer carcasses, an increase in the number of deer is expected to lead to changes in the red fox diet. In this study, the diet and sightings of red foxes inside and outside the fence were compared. Generalized linear mixed models indicate that the sika deer remains, ground-dwelling insects (Scarabaeidae and Rhaphidophoridae as a group, and Carabidae), and earthworms increased in the fox diet outside the fence, while the ingestion of voles decreased. The difference in prey consumption by red foxes was probably caused by differences in prey availability inside and outside the fence or the presence of available alternative food. These results suggest that red foxes demonstrate dietary plasticity in areas where habitat structure has been substantially modified by deer grazing. Although the abundance of voles, the primary food of red foxes, decreased outside the fence, the sighting rates of red foxes obtained by spotlight count were not significantly different between inside and outside the fence, suggesting that the presence of the others increased or available alternative food may have compensated for the negative effects of decreasing vole abundance.

最近的研究表明，日本奥库日光深防栅栏外，梅花鹿（Cervus nippon）种群数量的减少会减少啮齿动物的数量，但会增加几种无脊椎动物（Scarabaeidae，Rhaphidophoridae和earth）的种群数量。因此，赤狐日粮（赤狐）以这些动物为食的动物预计会根据猎物丰度的变化而变化。由于赤狐也能清除鹿的尸体，因此鹿的数量增加有望导致赤狐饮食的变化。在这项研究中，比较了篱笆内外的红狐的饮食和目击情况。广义线性混合模型表明，在围栏外的狐狸饮食中，梅花鹿仍然存在，地上有昆虫（Scarabaeidae和Rhaphidophoridae作为一组，Carabidae），worm增加了，而田鼠的摄食减少了。狐狸消耗的猎物的差异可能是由于围墙内外的猎物可利用性不同或存在替代食物所致。这些结果表明，狐狸在鹿的放牧对栖息地结构有重大影响的地区显示出饮食可塑性。尽管栅栏外田鼠数量丰富，是赤狐的主要食物，但通过聚光灯计数获得的赤狐的发现率在栅栏内外均无显着差异，这表明栅栏内外其他狐狸的数量增加或可用食物可能弥补了田鼠数量减少带来的负面影响。