TY - JOUR
T1 - Interacting effects of wildlife loss and climate on ticks and tick-borne disease
AU - Titcomb, Georgia
AU - Allan, Brian F.
AU - Ainsworth, Tyler
AU - Henson, Lauren
AU - Hedlund, Tyler
AU - Pringle, Robert Mitchell
AU - Palmer, Todd M.
AU - Njoroge, Laban
AU - Campana, Michael G.
AU - Fleischer, Robert C.
AU - Mantas, John Naisikie
AU - Young, Hillary S.
N1 - Publisher Copyright:
© 2017 The Author(s) Published by the Royal Society. All rights reserved.
PY - 2017/9/13
Y1 - 2017/9/13
N2 - Both large-wildlife loss and climatic changes can independently influence the prevalence and distribution of zoonotic disease. Given growing evidence that wildlife loss often has stronger community-level effects in low-productivity areas, we hypothesized that these perturbations would have interactive effects on disease risk. We experimentally tested this hypothesis by measuring tick abundance and the prevalence of tick-borne pathogens (Coxiella burnetii and Rickettsia spp.) within long-term, size-selective, large-herbivore exclosures replicated across a precipitation gradient in East Africa. Totalwildlife exclusion increased total tick abundance by 130% (mesic sites) to 225% (dry, lowproductivity sites), demonstrating a significant interaction of defaunation and aridity on tick abundance. When differing degrees of exclusion were tested for a subset of months, total tick abundance increased from 170% (only mega-herbivores excluded) to 360% (all largewildlife excluded).Wildlife exclusion differentially affected the abundance of the three dominant tick species, and this effect varied strongly over time, likely due to differences among species in their host associations, seasonality, and other ecological characteristics. Pathogen prevalence did not differ acrosswildlife exclusion treatments, rainfall levels, or tick species, suggesting that exposure riskwill respond to defaunation and climate change in proportion to total tick abundance. These findings demonstrate interacting effects of defaunation and aridity that increase disease risk, and they highlight the need to incorporate ecological context when predicting effects of wildlife loss on zoonotic disease dynamics.
AB - Both large-wildlife loss and climatic changes can independently influence the prevalence and distribution of zoonotic disease. Given growing evidence that wildlife loss often has stronger community-level effects in low-productivity areas, we hypothesized that these perturbations would have interactive effects on disease risk. We experimentally tested this hypothesis by measuring tick abundance and the prevalence of tick-borne pathogens (Coxiella burnetii and Rickettsia spp.) within long-term, size-selective, large-herbivore exclosures replicated across a precipitation gradient in East Africa. Totalwildlife exclusion increased total tick abundance by 130% (mesic sites) to 225% (dry, lowproductivity sites), demonstrating a significant interaction of defaunation and aridity on tick abundance. When differing degrees of exclusion were tested for a subset of months, total tick abundance increased from 170% (only mega-herbivores excluded) to 360% (all largewildlife excluded).Wildlife exclusion differentially affected the abundance of the three dominant tick species, and this effect varied strongly over time, likely due to differences among species in their host associations, seasonality, and other ecological characteristics. Pathogen prevalence did not differ acrosswildlife exclusion treatments, rainfall levels, or tick species, suggesting that exposure riskwill respond to defaunation and climate change in proportion to total tick abundance. These findings demonstrate interacting effects of defaunation and aridity that increase disease risk, and they highlight the need to incorporate ecological context when predicting effects of wildlife loss on zoonotic disease dynamics.
KW - Climate
KW - Coxiella burnetii
KW - Defaunation
KW - Exclosure
KW - Tick-borne disease
KW - Ticks
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UR - http://www.scopus.com/inward/citedby.url?scp=85029216501&partnerID=8YFLogxK
U2 - 10.1098/rspb.2017.0475
DO - 10.1098/rspb.2017.0475
M3 - Article
C2 - 28878055
AN - SCOPUS:85029216501
SN - 0962-8452
VL - 284
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1862
M1 - 20170475
ER -