腸胃道寄生蟲與其宿主有很密切的關係。高品質的宿主個體可以增加寄生蟲的適存度，另外某些宿主物種相較於其他物種更能支撐起穩定的寄生蟲族群和多樣的寄生蟲群聚。因此，判別出形塑寄生蟲盛行率(prevalence)、寄生蟲豐度(richness)和感染強度(infection intensity)的重要宿主特徵是很重要的生態議題。在此篇研究中，我調查臺灣山區四種共域的小型囓齒目動物，分別是臺灣森鼠(Apodemus semotus)、高山白腹鼠(Niviventer culturatus)、高山田鼠(Microtus kikuchii)與黑腹絨鼠(Eothenomys melanogaster)。我檢驗這些囓齒目宿主的性別、體重和使用的微氣候(溫度與相對溼度)使否與其腸胃道寄生蟲(線蟲與絛蟲)的盛行率、寄生蟲豐度和感染強度有關。我在不同的季節裡以活捉式陷阱在五個地點(合歡山、觀霧、思源埡口、大雪山、塔塔加)捕捉齧齒目宿主。我利用宿主的糞便李的蟲卵辨識出七種寄生蟲分類群(strongyle nematodes, spirurian nematodes, ascarid nematodes, Capillaria spp, Trichuris spp, Syphacia spp and Hymenolepis spp)，並且利用每克糞便中的蟲卵數(strongylid FEC)量化strongylids (Heligmonoides spp, Heligmosomoides spp)的感染強度。我發現兩種鼠科動物(A. semotus, N. culturatus)比與他們共域的倉鼠科動物(E. melanogaster, M. kikuchii)有著更高的盛行率與寄生蟲豐度。對擁有足夠樣本可分析宿主個體特徵的兩種鼠科動物來說，宿主體重比起宿主性別、使用的微氣候等更可能影響寄生蟲盛行率與感染強度。此篇研究提供在多宿主系統(小型囓齒目-腸胃道寄生蟲)上提供珍貴的野外資料。

Intestinal parasites have a close relationship with their hosts. A high quality host individual could enhance parasite fitness, and some host species are more likely than others to support stable parasite populations and diverse parasite communities. Therefore, it is important to understand host characteristics that shape parasite prevalence, richness and infection intensity. In this study, I surveyed four sympatric rodent species, the Taiwan field mouse (Apodemus semotus), oldfield white-bellied rat (Niviventer culturatus), Taiwan vole (Microtus kikuchii) and Père David’s vole (Eothenomys melanogaster), in the montane region of Taiwan. I examined whether host sex, host body mass and microclimate (temperature, relative humidity) are associated with the prevalence, richness and infection intensity of intestinal nematodes and cestodes in these rodents. I live-trapped rodents across five sites (i.e. Mt. Hehuan, Guanwu, Siyuan Pass, Mt. Dasyue, Tataka) between 2015 and 2016. I identified seven parasite taxa (strongyle nematodes, spirurian nematodes, ascarid nematodes, Capillaria spp, Trichuris spp, Syphacia spp and Hymenolepis spp), and quantified infection intensity of strongylids (Heligmonoides spp, Heligmosomoides spp) using fecal egg count (strongylid FEC). I found that the two murids (A. semotus, N. culturatus) had higher prevalence and richness of intestinal parasites than their sympatric cricetids (E. melanogaster, M. kikuchii). For the two murids that had sufficient sample sizes for host characteristics analyses, I found that host body mass but not host sex or microclimate, played a role in shaping parasite prevalence and infection intensity. This study provided valuable empirical data on a multiple ‘rodent hosts – intestinal parasites’ system.

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