- 著者
-
Hashimoto Takuma
Abe Manabu
- 出版者
- 日本哺乳類学会
- 雑誌
- Mammal study = The Continuation of the Journal of the Mammalogical Society of Japan (ISSN:13434152)
- 巻号頁・発行日
- vol.26, no.1, pp.35-44, 2001-06-01
- 被引用文献数
-
2
4
Two species of moles, <i>Mogera tokudae</i> and <i>M. imaizumii</i>, are parapatrically distributed in the Echigo Plain in the northern part of Niigata Prefecture, Japan. The two species are morphologically similar, except for the larger body size of <i>M. tokudae</i>. To clarify whether interspecific competition affects body size and reproductive traits of these moles, we compared these characteristics in syntopic populations with those in allopatric populations for both species in the Echigo Plain. <i>Mogera tokudae</i> exhibited little body size difference between allopatric and syntopic populations, while body size of <i>M. imaizumii</i> in syntopic populations was significantly smaller than in allopatric populations. Although litter sizes of both species were almost the same, reproductive schedules were different. Pregnant <i>M. tokudae</i> were captured mostly in late April, whereas <i>M. imaizumii</i> had a longer period of reproduction from March to October; some individuals bred twice a year. The relatively small body size and the longer breeding period observed in <i>M. imaizumii</i> of the Echigo Plain may be tactics for increasing reproductive success under severe interspecific competition from <i>M. tokudae</i>.