The use of ultraviolet (UV) cues for intra- and inter-specific communication is common in many animal species. Still, the role of UV signals under some predator-prey contexts, such as Batesian mimicry, is not clear. Batesian mimicry is a defensive strategy by which a palatable species (the mimic) resembles an unpalatable or noxious species (the model) to avoid predation. This strategy has evolved independently in many different taxa that are predated by species capable of UV perception. Moreover, there is considerable variation in how accurately Batesian mimics resemble their models across species. Our aim was to investigate how UV colour contributed to mimetic accuracy using several ant-mimicking spider species as a case study. We measured the reflectance spectrum (300-700 nm) for several species of mimics and models, and we tested whether they differ in visible and UV colour. We modelled whether two different predators could discriminate between mimics and models using colour information. We found that generally, ant-mimicking spiders differed significantly from their ant models in UV colour and that information from the visible range of light cannot be extrapolated into the UV. Our modelling suggested that wasps should be able to discriminate between mimics and models combining information from visible and the UV light, whereas birds may not discriminate between them. Thus, we show that UV colour can influence mimic accuracy and we discuss its potential role in Batesian mimicry. We conclude that colour, especially in the UV range, should be taken into account when measuring mimetic accuracy.

Department of Biological Sciences Macquarie University North Ryde Sydney NSW 2109 Australia

Department of Botany and Zoology Faculty of Sciences Masaryk University Kotlářská 2 61137 Brno Czech Republic

See more in PubMed

Trends Ecol Evol. 1995 Nov;10(11):455-60 PubMed

J Anim Ecol. 2014 Jul;83(4):779-90 PubMed

Annu Rev Entomol. 2001;46:471-510 PubMed

J Exp Biol. 2001 Jul;204(Pt 14):2499-507 PubMed

J Exp Biol. 2013 Oct 15;216(Pt 20):3886-95 PubMed

Vision Res. 1994 Jun;34(11):1489-508 PubMed

Proc Biol Sci. 2007 Jul 7;274(1618):1583-9 PubMed

J Evol Biol. 2007 Jan;20(1):286-95 PubMed

Nature. 2003 Jan 23;421(6921):334 PubMed

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2005 Jun;191(6):547-57 PubMed

Biol Rev Camb Philos Soc. 1993 Aug;68(3):413-71 PubMed

Curr Biol. 2008 May 6;18(9):699-703 PubMed

Proc Biol Sci. 2007 Jun 22;274(1617):1457-64 PubMed

J Exp Biol. 2001 Jul;204(Pt 14):2571-80 PubMed

J Exp Biol. 2005 Oct;208(Pt 20):3925-31 PubMed

Am Nat. 2011 Jul;178(1):124-34 PubMed

Q Rev Biol. 2013 Dec;88(4):297-315 PubMed

Am Nat. 2014 Feb;183(2):281-9 PubMed

Am Nat. 2012 Jan;179(1):38-51 PubMed

PLoS One. 2014 May 14;9(5):e96646 PubMed

Am Nat. 2015 Jun;185(6):705-24 PubMed

Proc Biol Sci. 2003 May 7;270(1518):897-904 PubMed

Nature. 2012 Mar 21;483(7390):461-4 PubMed

J Comp Physiol A. 1998 Nov;183(5):621-33 PubMed

Proc Biol Sci. 2000 Mar 7;267(1442):445-52 PubMed

J Comp Physiol A. 2000 Sep;186(9):897-901 PubMed

Nature. 2002 Jan 10;415(6868):133 PubMed

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2006 Aug;192(8):871-8 PubMed

Proc Biol Sci. 2005 Aug 7;272(1572):1541-6 PubMed

Annu Rev Entomol. 1998;43:619-43 PubMed

J Comp Physiol A. 1992 Jan;170(1):23-40 PubMed

Mimetic accuracy and co-evolution of mimetic traits in ant-mimicking species