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The Role of Vole Populations in Prevalence of the Parasite (Echinococcus multilocularis) in Foxes
| Title: | The Role of Vole Populations in Prevalence of the Parasite (Echinococcus multilocularis) in Foxes |
| Authors: | SAITOH, Takashi Browse this author | | TAKAHASHI, Kenichi Browse this author |
| Keywords: | Clethrionomys rufocanus | | density-dependence | | functional response | | numerical response | | Vulpes vulpes |
| Issue Date: | 1998 |
| Publisher: | Society of Population Ecology |
| Journal Title: | Researches on population ecology |
| Volume: | 40 |
| Issue: | 1 |
| Start Page: | 97 |
| End Page: | 105 |
| Abstract: | Effects of population fluctuation of the gray-sided vole (Clethrionomys rufocanus) on the prevalence (infection rates) of the parasite Echinococcus multilocularis in red fox (Vulpes vulpes) populations was investigated from 1985 to 1992 in eastern Hokkaido (Abashiri, Nemuro, and Kushiro area), Japan. This parasite needs two hosts to complete its life cycle; the gray-sided vole as its intermediate host and the red fox as its final host. We found that: (1) Infection rates in foxes depended on the current-year abundance of voles in all three study areas, particularly in Abashiri. (2) In addition to this direct density-dependence, delayed density-dependence between the infection rate and the prior-year abundance of voles was detected in Nemuro and in Kushiro. (3) The regional differences in density-dependence pattern were related to regional differences in the winter food habits of red foxes: in Abashiri the proportion of voles in the fox's diet greatly decreases in winter, while the proportion remains high in winter in Nemuro and in Kushiro, probably because of shallower snowpack. These results suggest that infection rates in foxes in Abashiri were less influenced by the prior-year prevalence, since the infection cycle might be interrupted in winter, when voles became less important in fox's diet. In contrast, the state of the prevalence may carry over from year to year in Nemuro and in Kushiro, because red foxes continue to eat a considerable amount of voles throughout year. The regionally contrasted results for the relationship between infection rate in foxes and vole abundance were parallel to the regional difference in fluctuation pattern of vole populations, which are highly variable in Abashiri area, but less variable in Kushiro-Nemuro area. Drastic change in vole populations appears to affect the host-parasite system. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/17002 |
| Appears in Collections: | 北方生物圏フィールド科学センター (Field Science Center for Northern Biosphere) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 齊藤 隆
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