Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease.
The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian declines, putatively caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), was tenuous because it was based on a temporally confounded correlation. Here we provide temporally unconfounded evidence that global El Niño climatic events drive widespread amphibian losses in genus Atelopus via increased regional temperature variability, which can reduce amphibian defenses against pathogens. Of 26 climate variables tested, only factors associated with temperature variability could account for the spatiotemporal patterns of declines thought to be associated with Bd. Climatic predictors of declines became significant only after controlling for a pattern consistent with epidemic spread (by temporally detrending the data). This presumed spread accounted for 59% of the temporal variation in amphibian losses, whereas El Niño accounted for 59% of the remaining variation. Hence, we could account for 83% of the variation in declines with these two variables alone. Given that global climate change seems to increase temperature variability, extreme climatic events, and the strength of Central Pacific El Niño episodes, climate change might exacerbate worldwide enigmatic declines of amphibians, presumably by increasing susceptibility to disease. These results suggest that changes to temperature variability associated with climate change might be as significant to biodiversity losses and disease emergence as changes to mean temperature.
Rohr
Jason R
JR
Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA. jasonrohr@gmail.com
Raffel
Thomas R
TR
D000820:Animal Diseases; D000818:Animals; D002025:Bufonidae / Q000502:physiology*; D057231:Climate Change; D004198:Disease Susceptibility; D010140:Pacific Ocean; D011157:Population Dynamics; D013997:Time Factors
Proc Natl Acad Sci U S A. 2008 Nov 11;105(45):17436-41
18987318
PLoS Biol. 2004 Nov;2(11):e351
15502873
Trends Ecol Evol. 2010 Feb;25(2):109-18
19836101
Ecology. 2009 Mar;90(3):588-97
19341131
Science. 2000 Jan 21;287(5452):443-9
10642539
Science. 2006 Dec 15;314(5806):1740-5
17170296
PLoS Biol. 2008 Mar 25;6(3):e72
18366257
Nature. 2007 May 31;447(7144):E3-4; discussion E5-6
17538571
Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):13645-6
19706496
Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):12901-6
12228724
Oecologia. 2003 May;135(4):657-64
16228260
Nature. 2008 Feb 21;451(7181):990-3
18288193
Ecol Appl. 2008 Oct;18(7):1743-53
18839768
J Comp Physiol B. 1997 May;167(4):256-63
9203367
Science. 2002 Jun 21;296(5576):2158-62
12077394
Nature. 2001 Apr 5;410(6829):681-4
11287952
Proc Natl Acad Sci U S A. 2008 May 6;105(18):6668-72
18458348
FEBS Lett. 2000 Oct 20;483(2-3):135-8
11042268
Science. 2004 Dec 3;306(5702):1783-6
15486254
Trends Ecol Evol. 2008 Nov;23(11):610-8
18823679
Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):13844-9
19666598
Nature. 2008 Oct 30;455(7217):1235-9
18972018
Aust Vet J. 2004 Jul;82(7):434-9
15354853
Vet Immunol Immunopathol. 1991 Jul;28(3-4):365-77
1949572
Science. 2008 Jun 6;320(5881):1296-7
18535231
Nature. 2006 Jan 12;439(7073):161-7
16407945
Proc Natl Acad Sci U S A. 2007 May 15;104(20):8352-6
17449638
Ann N Y Acad Sci. 2010 May;1195:129-48
20536821
Nature. 2009 Sep 24;461(7263):511-4
19779449
Ecology. 2009 Apr;90(4):888-900
19449681
Proc Natl Acad Sci U S A. 2006 Feb 28;103(9):3165-70
16481617
J Leukoc Biol. 1994 Dec;56(6):729-31
7996049
Nature. 2005 Aug 4;436(7051):696-700
16079845
Proc Natl Acad Sci U S A. 2003 Aug 19;100(17):9997-10001
12913128
Nature. 2002 Feb 21;415(6874):905-9
11859368
Proc Natl Acad Sci U S A. 2008 Nov 4;105(44):16988-93
18955700
Proc Biol Sci. 2007 Jan 22;274(1607):253-60
17148254
Ecology. 2008 Jun;89(6):1627-39
18589527