Fox Bait Consumption and Camera Trapping in Agricultural Areas in Eastern Hokkaido, Japan

Abstract

The red fox (Vulpus vulpus) is found throughout much of the northern hemisphere and most of Australia and has a broad range of habitats, from deserts to arctic tundra (e.g., Saunders et al. 1995). In Japan, this animal is common in Hokkaido, Honshu, Shikoku, and Kyushu islands (e.g., Uraguchi 2009). On Hokkaido Island (Fig. 1), red foxes transmit the dangerous zoonotic disease, alveolar echinococcosis, caused by the metacestode stage of Echinococcus multilocularis (e.g., Yamashita and Kamiya 1997; Hokkaido Institute of Public Health 2011). This disease is widespread in the northern hemisphere (Eckert et al. 2001; Soulsbury et al. 2010). Red foxes are the principal definitive hosts in the natural environments and the main infection source for humans. In recent years, the infection rate among red foxes in Hokkaido is around 40% (Takahashi et al. 2005; Nonaka et al. 2006). Therefore, it is important to evaluate the intervention strategies, especially as the administration of anthelmintics to red foxes in Hokkaido. Baiting foxes with the anthelmintic praziquantel successfully reduced E. multilocularis prevalence in red foxes in Germany and Switzerland (Schelling et al. 1997; Tachmann et al. 2001; Hegglin et al. 2003; Romig et al. 2007). In Hokkaido, small scale trials of baiting foxes with praziquantel were carried out in Koshimizu (Tsukada et al. 2002), Nemuro (Takahashi et al. 2002), Otaru (Nonaka et al. 2006) and Kutchan (Hokkaido Government 2007). Tsukada (2005) suggested that red foxes might prefer natural foods to artificial foods, as long as they can obtain natural foods from their environment. The red fox diet varies seasonally and regionally, including small mammals, birds, insects, fruits and carcasses of large mammals (Yoneda 2005; Uraguchi 2008, 2009). To establish an effective baiting method, it is important to identify seasonal differences in bait consumption by red foxes and other animals. The Tokachi District of Hokkaido is representative of Japan’s agricultural areas. As red foxes frequently appear in agricultural areas, it is important to provide them with fox bait containing the anthelmintic praziquantel. In agricultural area, many other animals such as domestic dogs, domestic cats, weasels and crows may also consume the bait. When other animals frequently consume the bait, it becomes difficult to evaluate its effect. For more effective baiting, it is important to identify the animals using the fox baits. Since the environment of agricultural areas changes due to harvesting and planting activities, it would be needed to evaluate the fox bait’s seasonal effectiveness. We used automatic digital cameras with infrared sensors to obtain this fundamental information on fox bait consumption by animals in an agricultural area. We examined seasonal differences in numbers of animals (including red foxes) occurring at baiting sites in the Tokachi District and seasonal differences in bait disappearance by red foxes and other animals.