title: Shifting latitudinal clines in avian body size correlate with global warming in Australian passerines.
abstract: Intraspecific latitudinal clines in the body size of terrestrial vertebrates, where members of the same species are larger at higher latitudes, are widely interpreted as evidence for natural selection and adaptation to local climate. These clines are predicted to shift in response to climate change. We used museum specimens to measure changes in the body size of eight passerine bird species from south-eastern Australia over approximately the last 100 years. Four species showed significant decreases in body size (1.8-3.6% of wing length) and a shift in latitudinal cline over that period, and a meta-analysis demonstrated a consistent trend across all eight species. Southern high-latitude populations now display the body sizes typical of more northern populations pre-1950, equivalent to a 7 degrees shift in latitude. Using ptilochronology, we found no evidence that these morphological changes were a plastic response to changes in nutrition, a likely non-genetic mechanism for the pattern observed. Our results demonstrate a generalized response by eight avian species to some major environmental change over the last 100 years or so, probably global warming.
authors.affiliation: Department of Botany & Zoology, Research School of Biology, Australian National University, Canberra, Australia. janet.gardner@anu.edu.au
authors.forename: Janet L
authors.initials: JL
authors.lastname: Gardner
authors.forename: Robert
authors.initials: R
authors.lastname: Heinsohn
authors.forename: Leo
authors.initials: L
authors.lastname: Joseph
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001315:Australia; D049628:Body Size / Q000502:physiology*; D017752:Greenhouse Effect; D046109:Passeriformes / Q000502:physiology*; D014921:Wings, Animal / Q000033:anatomy & histology
references.citation: Evolution. 1971 Mar;25(1):1-28
references.pmid: 28562938
references.citation: Science. 2006 Jul 14;313(5784):224-6
references.pmid: 16840700
references.citation: J Evol Biol. 2006 Mar;19(2):309-20
references.pmid: 16599906
references.citation: Trends Ecol Evol. 2000 Feb;15(2):56-61
references.pmid: 10652556
references.citation: Science. 2005 Oct 14;310(5746):304-6
references.pmid: 16224020
references.citation: Science. 2000 Jan 14;287(5451):308-9
references.pmid: 10634786
references.citation: Proc Biol Sci. 2001 Mar 7;268(1466):487-91
references.pmid: 11296860
references.citation: Proc Biol Sci. 2004 Feb 22;271(1537):435-40
references.pmid: 15101703
references.citation: Am Nat. 2009 Jan;173(1):119-23
references.pmid: 19049440
references.citation: Science. 2001 Apr 27;292(5517):662-7
references.pmid: 11326088
references.citation: Proc Natl Acad Sci U S A. 2008 Sep 9;105(36):13492-6
references.pmid: 18757740
references.citation: Proc Natl Acad Sci U S A. 2004 Dec 28;101(52):18042-7
references.pmid: 15601765
references.citation: Science. 2005 Apr 29;308(5722):691-3
references.pmid: 15860627
references.citation: Genetica. 2001;112-113:183-98
references.pmid: 11838765
references.citation: Trends Ecol Evol. 1998 Feb 1;13(2):77-81
references.pmid: 21238209
references.citation: Proc Biol Sci. 2003 Apr 22;270(1517):799-803
references.pmid: 12737657
references.citation: Proc Biol Sci. 2001 May 7;268(1470):947-52
references.pmid: 11370968
references.citation: Ecol Lett. 2009 Mar;12(3):249-59
references.pmid: 19245587
references.citation: Mol Ecol. 2008 Jan;17(1):167-78
references.pmid: 18173499
references.citation: Evolution. 1995 Apr;49(2):241-251
references.pmid: 28565006
references.citation: Nature. 2003 Jan 2;421(6918):37-42
references.pmid: 12511946
references.citation: Evolution. 1980 Jul;34(4):638-653
references.pmid: 28563981
references.citation: J Anim Ecol. 2008 Nov;77(6):1143-52
references.pmid: 18624741