Sampling, Distribution, Dispersal Host–Parasite Associations in Small Mammal Communities in Semiarid Savanna Ecosystems of East Africa Ana Sofia Guerra, 1,2 Ralph P. Eckerlin, 3 Ashley P. G. Dowling, 4 Lance A. Durden, 5 Richard G. Robbins, 6 Katharina Dittmar, 7 Kristofer M. Helgen, 8 Bernard Agwanda, 9 Brian F. Allan, 10 Tyler Hedlund, 10 and Hillary S. Young 1 1 Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA (ana.sofia.guerra@ lifesci.ucsb.edu; hillary.young@lifesci.ucsb.edu), 2 Corresponding author, e-mail: ana.sofia.guerra@lifesci.ucsb.edu, 3 Natural Sciences Division, Northern Virginia Community College, Annandale, VA (reckerlin@nvcc.edu), 4 Department of Entomology, University of Arkansas, Fayetteville, AR (adowling@uark.edu), 5 Department of Biology, Georgia Southern University, Statesboro, GA (ldurden@ georgiasouthern.edu), 6 Armed Forces Pest Management Board, Office of the Assistant Secretary of Defense for Energy, Installations and Environment, Silver Spring, MD (richard.g.robbins.civ@mail.mil), 7 Department of Biological Sciences, SUNY Buffalo, Buffalo, NY (kd52@buffalo.edu), 8 Division of Mammals, National Museum of Natural History, Smithsonian Institution, Washington, DC (helgenk@ si.edu), 9 Mammal Section, National Museums of Kenya, Nairobi, Kenya (benrisky@gmail.com), and 10 Department of Entomology, University of Illinois Urbana-Champaign, Urbana, IL (ballan@life.illinois.edu; pannaking22@aol.com) Received 25 November 2015; Accepted 22 March 2016 Abstract Despite the established importance of rodents as reservoirs of vector-borne zoonoses in East Africa, there is rela- tively limited information regarding the infestation parameters and host associations of ectoparasites that vector many such pathogens among small mammals in this region. Between 2009 and 2013, small mammals were live- trapped in the semiarid savanna of Kenya. A subset of these individual hosts, including 20 distinct host taxa, was examined for ectoparasites, which were identified to species. Species of fleas, ticks, mites, and sucking lice were recorded. Based on these data, we calculated host-specific infestation parameters, documented host preferences among ectoparasites, conducted a rarefaction analysis and extrapolation to determine if ectoparasites were ade- quately sampled, and assessed nestedness for fleas to understand how pathogens might spread in this system. We found that the flea community structure was significantly nested. Understanding the ectoparasite network structure may have significant human relevance, as at least seven of the ectoparasite species collected are known vectors of pathogens of medical importance in the region, including Yersinia pestis, Rickettsia spp., and Theileria parva, the causative agents of plague, spotted fevers and other rickettsial illnesses in humans, and theileriosis, respectively. Key words: flea, louse, mite, tick, ectoparasite Rodents and other small mammals are primary reservoirs of many vector-borne pathogens of medical and veterinary significance throughout the world, including the causative agents for Lyme dis- ease, hantaviral diseases, and hemorrhagic fevers (Meerburg et al. 2009, McFarlane et al. 2012, Luis et al. 2013, Han et al. 2015, Morand et al. 2015). In East Africa, important vector-borne patho- gens with small mammal reservoirs include Yersinia pestis (plague), Borrelia spp. (tick-borne relapsing fever), Rickettsia spp. (spotted fevers, murine typhus, and other rickettsial illnesses), Bartonella spp. (cat scratch disease, trench fever, bacillary angiomatosis, etc.), and Theileria parva (livestock theileriosis; Pearse 1929, Roberts 1939, Heisch et al. 1953, Norval et al. 1992, Mediannikov et al. 2010, Zimba et al. 2012, Leulmi et al. 2014). These pathogens have serious social and economic consequences; in 1989, a regional loss equivalent to US$168 million was attributed to theileriosis alone (Mukhebi et al. 1992). The significance of small mammals in the dynamics of disease in these systems will depend strongly on host– vector associations – including the host specificity of the vectors, and the intensity of infestation of these ectoparasites. There have been relatively few studies of such associations in East Africa (Roberts 1936, 1939; Heisch et al. 1953; Schwan 1986; Laudisoit et al. 2007; Oguge et al. 2009; Sang et al. 2011), and none that ex- plores details of host–parasite networks from the woody semiarid savanna ecosystem that dominates much of East Africa. In this study, we aim to not only document host–ectoparasite as- sociations across a range of taxonomic groups, but also understand V C The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com 851 Journal of Medical Entomology, 53(4), 2016, 851–860 doi: 10.1093/jme/tjw048 Advance Access Publication Date: 25 April 2016 Research article by guest on October 4, 2016 http://jme.oxfordjournals.org/ Downloaded from