Refugia and connectivity sustain amphibian metapopulations afflicted by disease

Geoffrey W. Heard*, Chris D. Thomas, Jenny A. Hodgson, Michael P. Scroggie, David S L Ramsey, Nick Clemann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Metapopulation persistence in fragmented landscapes depends on habitat patches that can support resilient local populations and sufficient connectivity between patches. Yet epidemiological theory for metapopulations has largely overlooked the capacity of particular patches to act as refuges from disease, and has suggested that connectivity can undermine persistence. Here, we show that relatively warm and saline wetlands are environmental refuges from chytridiomycosis for an endangered Australian frog, and act jointly with connectivity to sustain frog metapopulations. We coupled models of microclimate and infection probability to map chytrid prevalence, and demonstrate a strong negative relationship between chytrid prevalence and the persistence of frog populations. Simulations confirm that frog metapopulations are likely to go extinct when they lack environmental refuges from disease and lose connectivity between patches. This study demonstrates that environmental heterogeneity can mediate host-pathogen interactions in fragmented landscapes, and provides evidence that connectivity principally supports host metapopulations afflicted by facultative pathogens.

Original languageEnglish
Pages (from-to)853-863
Number of pages11
JournalEcology Letters
Volume18
Issue number8
Early online date25 Jun 2015
DOIs
Publication statusPublished - 14 Jul 2015

Bibliographical note

© 2015 John Wiley & Sons Ltd/CNRS. This is an author produced version of a paper accepted for publication in Ecology Letters. Uploaded in accordance with the publisher's self-archiving policy.

Keywords

  • Amphibian
  • Chytrid
  • Colonisation
  • Conservation
  • Extinction
  • Litoria raniformis
  • Microclimate
  • Pathogen
  • Reservoir host

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