title: Does avian conspicuous colouration increase or reduce predation risk?
abstract: Animals often announce their unprofitability to predators through conspicuous coloured signals. Here we tested whether the apparently conspicuous colour designs of the four European Coraciiformes and Upupiformes species may have evolved as aposematic signals, or whether instead they imply a cost in terms of predation risk. Because previous studies suggested that these species are unpalatable, we hypothesized that predators could avoid targeting them based on their colours. An experiment was performed where two artificial models of each bird species were exposed simultaneously to raptor predators, one painted so as to resemble the real colour design of these birds, and the other one painted using cryptic colours. Additionally, we used field data on the black kite's diet to compare the selection of these four species to that of other avian prey. Conspicuous models were attacked in equal or higher proportions than their cryptic counterparts, and the attack rate on the four species increased with their respective degree of contrast against natural backgrounds. The analysis of the predator's diet revealed that the two least attacked species were negatively selected in nature despite their abundance. Both conspicuous and cryptic models of one of the studied species (the hoopoe) received fewer attacks than cryptic models of the other three species, suggesting that predators may avoid this species for characteristics other than colour. Globally, our results suggest that the colour of coraciiforms and upupiforms does not function as an aposematic signal that advises predators of their unprofitability, but also that conspicuous colours may increase predation risk in some species, supporting thus the handicap hypothesis.
authors: Department of Functional and Evolutionary Biology, Estación Experimental de Zonas Áridas, Almería, Spain. magda@eeza.csic.es
authors: M
authors: M
authors: Ruiz-Rodríguez
authors: J M
authors: JM
authors: Avilés
authors: J J
authors: JJ
authors: Cuervo
authors: D
authors: D
authors: Parejo
authors: F
authors: F
authors: Ruano
authors: C
authors: C
authors: Zamora-Muñoz
authors: F
authors: F
authors: Sergio
authors: L
authors: L
authors: López-Jiménez
authors: A
authors: A
authors: Tanferna
authors: M
authors: M
authors: Martín-Vivaldi
mesh_terms: D000819:Animal Communication; D000818:Animals; D001717:Birds / Q000033:anatomy & histology*; D003116:Color; D003463:Cues; D004032:Diet; D011235:Predatory Behavior; D020304:Raptors / Q000502:physiology*; D012307:Risk Factors
references: Evolution. 1997 Dec;51(6):2050-2053
references: 28565127
references: Philos Trans R Soc Lond B Biol Sci. 2009 Feb 27;364(1516):481-8
references: 18990673
references: Trends Ecol Evol. 2006 Feb;21(2):83-8
references: 16701479
references: Proc Biol Sci. 2008 Oct 22;275(1649):2345-52
references: 18595836
references: Proc Natl Acad Sci U S A. 2000 Nov 21;97(24):12948-9
references: 11087849
references: Biol Lett. 2006 Sep 22;2(3):348-50
references: 17148400
references: Trends Ecol Evol. 2005 Nov;20(11):598-603
references: 16701442
references: J Exp Biol. 2009 Nov;212(Pt 22):3621-6
references: 19880722
references: Proc Biol Sci. 2004 Oct 22;271(1553):2135-42
references: 15475333
references: J Anim Ecol. 2009 Jan;78(1):109-18
references: 19120598
references: Proc Natl Acad Sci U S A. 2009 Nov 10;106(45):19072-7
references: 19858491
references: J Exp Biol. 2002 Dec;205(Pt 24):3925-35
references: 12432014
references: Am Nat. 2008 Mar;171(3):327-38
references: 18197756
references: Proc Biol Sci. 2005 Jul 7;272(1570):1315-21
references: 16006332
references: Nature. 2001 Oct 4;413(6855):512-4
references: 11586357
references: Proc Natl Acad Sci U S A. 2000 Nov 21;97(24):12970-5
references: 11035772
references: Proc Natl Acad Sci U S A. 2005 May 3;102(18):6391-4
references: 15851662
references: Mol Biol Evol. 2003 Jun;20(6):855-61
references: 12716987
references: Science. 2011 Jan 21;331(6015):327-30
references: 21252345
references: Appl Environ Microbiol. 2006 Jun;72(6):4245-9
references: 16751538
references: Proc Biol Sci. 1998 Mar 7;265(1394):351-8
references: 9523436
references: Proc Natl Acad Sci U S A. 2004 Nov 9;101(45):15857-60
references: 15520388
references: J Theor Biol. 2003 Sep 21;224(2):183-8
references: 12927525
references: Biol Lett. 2008 Oct 23;4(5):515-7
references: 18593669
references: Oecologia. 1974 Dec;14(4):413-417
references: 28308662
references: Ecol Lett. 2011 Jul;14(7):625-34
references: 21518211
references: Science. 1992 Oct 30;258(5083):799-801
references: 1439786
references: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2005 Oct;191(10):933-51
references: 16086150
references: J Comp Physiol A. 1998 Nov;183(5):621-33
references: 9839454
references: Proc Biol Sci. 2010 Jan 7;277(1678):123-30
references: 19812087
references: Proc Biol Sci. 2007 Jun 22;274(1617):1457-64
references: 17426012
references: Nature. 2005 Mar 3;434(7029):72-4
references: 15744301
references: Evolution. 2009 Feb;63(2):469-78
references: 19154362
references: J Evol Biol. 2009 Feb;22(2):376-86
references: 19196385
references: J Evol Biol. 2010 Feb;23(2):293-301
references: 20002251