Cryptic disease-induced mortality may cause host extinction in an apparently stable host–parasite system. Issue 1863 (27th September 2017)

• Record Type: Journal Article
• Authors: Valenzuela-Sánchez, Andrés; Schmidt, Benedikt R.; Uribe-Rivera, David E.; Costas, Francisco; Cunningham, Andrew A.; Soto-Azat, Claudio
• Is Part Of: Proceedings. Volume 284:Issue 1863(2017)
• Publication Date: 2017-09-27
• Subjects: chytridiomycosis -- Cormack–Jolly–Seber models -- Darwin's frogs -- epidemic and endemic emerging infectious disease -- matrix population models -- multi-state capture–recapture models; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2017.1176
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : The decline of wildlife populations due to emerging infectious disease often shows a common pattern: the parasite invades a naive host population, producing epidemic disease and a population decline, sometimes with extirpation. Some susceptible host populations can survive the epidemic phase and persist with endemic parasitic infection. Understanding host–parasite dynamics leading to persistence of the system is imperative to adequately inform conservation practice. Here we combine field data, statistical and mathematical modelling to explore the dynamics of the apparently stable Rhinoderma darwinii – Batrachochytrium dendrobatidis (Bd) system. Our results indicate that Bd-induced population extirpation may occur even in the absence of epidemics and where parasite prevalence is relatively low. These empirical findings are consistent with previous theoretical predictions showing that highly pathogenic parasites are able to regulate host populations even at extremely low prevalence, highlighting that disease threats should be investigated as a cause of population declines even in the absence of an overt increase in mortality.