Drought reduces chytrid fungus (Batrachochytrium dendrobatidis) infection intensity and mortality but not prevalence in adult crawfish frogs (Lithobates areolatus)

Vanessa C K Terrell, Nathan J. Engbrecht, Allan P. Pessier, Michael Lannoo

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

To fully understand the impacts of the chytrid fungus Batrachochytrium dendrobatidis (Bd) on amphibians it is necessary to examine the interactions between populations and their environment. Ecologic variables can exacerbate or ameliorate Bd prevalence and infection intensity, factors that are positively related when Bd is acting on naive amphibian populations as an epidemic disease. In crawfish frogs (Lithobates areolatus), a North American species with a complex life history, we have shown that Bd acts as an endemic disease with impacts that vary seasonally; the highest infection prevalences and intensities and highest frog mortality occurred during late spring in postbreeding individuals. In this study, conducted between 28 February and 23 August 2011 in southwestern Indiana on the same population, we report an uncoupling of the previously observed relationship between Bd prevalence and intensity following an extreme drought. Specifically, there was a postdrought reduction in Bd infection intensity and mortality, but not in infection prevalence. This result suggests that the relationship between prevalence and intensity observed in Bd epidemics can be uncoupled in populations harboring endemic infections. Further, constant prevalence rates suggest either that crawfish frogs are being exposed to Bd sources independent of ambient moisture or that low-level infections below detection thresholds persist from year to year. Drought has several ecologically beneficial effects for amphibians with complex life histories, including eliminating fish and invertebrate populations that feed on larvae. To these ecologic benefits we suggest another, that drought can reduce the incidence of the severe skin disease (chytridiomycosis) due to Bd infection.

Original languageEnglish
Pages (from-to)56-62
Number of pages7
JournalJournal of Wildlife Diseases
Volume50
Issue number1
DOIs
StatePublished - Jan 2014

Fingerprint

Lithobates
crayfish
frog
frogs
drought
fungus
mortality
fungi
infection
amphibian
amphibians
life history
skin diseases
skin
detection limit
invertebrate
invertebrates
moisture
larva
incidence

Keywords

  • Bd load model
  • Chytridiomycosis
  • Disease
  • Pathogen

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

Drought reduces chytrid fungus (Batrachochytrium dendrobatidis) infection intensity and mortality but not prevalence in adult crawfish frogs (Lithobates areolatus). / Terrell, Vanessa C K; Engbrecht, Nathan J.; Pessier, Allan P.; Lannoo, Michael.

In: Journal of Wildlife Diseases, Vol. 50, No. 1, 01.2014, p. 56-62.

Research output: Contribution to journalArticle

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