Ectoparasite assemblage of the four-striped mouse, Rhabdomys pumilio : the effect of anthropogenic habitat transformation and temporal variation

[摘要] ENGLISH ABSTRACT: Anthropogenic habitat transformation and subsequent fragmentation of natural vegetation isregarded as one of the largest threats to biodiversity in the world. The Cape Floristic Region(CFR) in the Western Cape Province of South Africa is classified as a biodiversity hotspot due toits high plant species diversity and endemism. Increasing growth in agricultural activities in thisregion has contributed to fragmentation of pristine natural vegetation. A diverse assemblage ofsmall mammal species are found in this region, but very little is known with regard to theirectoparasite diversity. More importantly, no information is available on the effect offragmentation on parasite burdens or species assemblages. The aims of the study were first torecord relative density, average body size and body condition of an endemic rodent, Rhabdomyspumilio, trapped in two habitat types (pristine natural areas and remnant fragments). Secondly,compare diversity and species composition of ectoparasite species on this rodent in the twohabitat types. In addition, body size measurements of the two most abundant flea species wererecorded and compared for the two habitat types. Lastly, temporal variation in mean abundanceof fleas, mites, ticks and the louse were recorded within a habitat fragment surrounded byvineyards. Three hundred and ten individuals of the Four-striped mouse, R. pumilio, weretrapped and euthanized at 8 localities (4 remnant habitat fragments and 4 pristine natural areas)in the CFR. All ectoparasites were removed and identified. A total of 8361 ectoparasites thatconsisted of 6 flea, 1 louse, 8 mites and 11 tick species were recorded. Mites and fleas werefound to be more abundant on mice during cool wet months, whereas ticks and the louse weremore abundant during the hot dry months of the year. Rodent host body size was larger and theywere in better body condition in remnant fragments compared to pristine natural localities. Apositive body size relationship was found between the flea, Listropsylla agrippinae, and the host,with larger fleas recorded on rodents that occur in fragments. Mean abundance and prevalence ofoverall ectoparasites combined and separately for ticks, mites, louse and fleas were higher infragments compared to natural localities. The study shows that R. pumilio is host to a largediversity of ectoparasite species in the CFR. Moreover, habitat fragments within agriculturallandscapes can facilitate higher parasite burdens and prevalence in rodent populations. This canlead to an increase in disease risk given that several of the parasite species are important vectorsof pathogens that can cause disease in domestic, wild animals and humans.

[发布机构] Stellenbosch University