Philosophical Transactions of the Royal Society B: Biological Sciences
Published:https://doi.org/10.1098/rstb.2008.0266

    Even if an animal matches its surroundings perfectly in colour and texture, any mismatch between the spatial phase of its pattern and that of the background, or shadow created by its three-dimensional relief, is potentially revealing. Nevertheless, for camouflage to be fully broken, the shape must be recognizable. Disruptive coloration acts against object recognition by the use of high-contrast internal colour boundaries to break up shape and form. As well as the general outline, characteristic features such as eyes and limbs must also be concealed; this can be achieved by having the colour patterns on different, but adjacent, body parts aligned to match each other (i.e. in phase). Such ‘coincident disruptive coloration’ ensures that there is no phase disjunction where body parts meet, and causes different sections of the body to blend perceptually. We tested this theory using field experiments with predation by wild birds on artificial moth-like targets, whose wings and (edible pastry) bodies had colour patterns that were variously coincident or not. We also carried out an experiment with humans searching for analogous targets on a computer screen. Both experiments show that coincident disruptive coloration is an effective mechanism for concealing an otherwise revealing body form.

    References

    • Chiao C.C& Hanlon R.T. 2001 Cuttlefish camouflage: visual perception of size, contrast and number of white squares on artificial checkerboard substrata initiates disruptive coloration. J. Exp. Biol. 204, 2119–2125. Crossref, PubMed, ISIGoogle Scholar
    • Chiao C.C, Kelman E.J& Hanlon R.T. 2005 Disruptive body patterning of cuttlefish (Sepia officinalis) requires visual information regarding edges and contrast of objects in natural substrate backgrounds. Biol. Bull. 208, 7–11.doi:10.2307/3593095. . Crossref, PubMed, ISIGoogle Scholar
    • Cott H.B Adaptive coloration in animals. 1940 London, UK:Methuen & Co. Ltd. Google Scholar
    • Cox D.R. 1972 Regression models and life-tables. J. R. Stat. Soc. B. 34, 187–220. Google Scholar
    • Cuthill I.C, Stevens M, Sheppard J, Maddocks T, Párraga C.A& Troscianko T.S. 2005 Disruptive coloration and background pattern matching. Nature. 434, 72–74.doi:10.1038/nature03312. . Crossref, PubMed, ISIGoogle Scholar
    • Fraser S, Callahan A, Klassen D& Sherratt T.N. 2007 Empirical tests of the role of disruptive coloration in reducing detectability. Proc. R. Soc. B. 274, 1325–1331.doi:10.1098/rspb.2007.0153. . Link, ISIGoogle Scholar
    • Kelman E.J, Baddeley R.J, Shohet A.J& Osorio D. 2007 Perception of visual texture and the expression of disruptive camouflage by the cuttlefish, Sepia officinalis. Proc. R. Soc. B. 274, 1369–1375.doi:10.1098/rspb.2007.0240. . Link, ISIGoogle Scholar
    • Klein J.P& Moeschberger M.L Survival analysis: techniques for censored and truncated data. 2003 New York, NY:Springer. Google Scholar
    • Mathger L.M, Chiao C.C, Barbosa A, Buresch K.C, Kaye S& Hanlon R.T. 2007 Disruptive coloration elicited on controlled natural substrates in cuttlefish, Sepia officinalis. J. Exp. Biol. 210, 2657–2666.doi:10.1242/jeb.004382. . Crossref, PubMed, ISIGoogle Scholar
    • Merilaita S. 1998 Crypsis through disruptive coloration in an isopod. Proc. R. Soc. B. 265, 1059–1064.doi:10.1098/rspb.1998.0399. . Link, ISIGoogle Scholar
    • Merilaita S. 2003 Visual background complexity facilitates the evolution of camouflage. Evolution. 57, 1248–1254.doi:10.1098/rspb.1998.0399. . Crossref, PubMed, ISIGoogle Scholar
    • Nakagawa S& Cuthill I.C. 2007 Effect size, confidence interval and statistical significance: a practical guide for biologists. Biol. Rev. 82, 591–605.doi:10.1111/j.1469-185X.2007.00027.x. . Crossref, PubMed, ISIGoogle Scholar
    • Rosenthal R, Rosnow R.L& Rubin D.B Contrasts and effect sizes in behavioral research. 2000 Cambridge, UK:Cambridge University Press. Google Scholar
    • Ruxton G.D, Sherratt T.N& Speed M.P Avoiding attack. The evolutionary ecology of crypsis, warning signals and mimicry. 2004 Oxford, UK:Oxford University Press. Google Scholar
    • Schaefer H.M& Stobbe N. 2006 Disruptive coloration provides camouflage independent of background matching. Proc. R. Soc. B. 273, 2427–2432.doi:10.1098/rspb.2006.3615. . Link, ISIGoogle Scholar
    • Shohet A.J, Baddeley R.J, Anderson J.C, Kelman E.J& Osorio D. 2006 Cuttlefish responses to visual orientation of substrates, water flow and a model of motion camouflage. J. Exp. Biol. 209, 4717–4723.doi:10.1242/jeb.02580. . Crossref, PubMed, ISIGoogle Scholar
    • SPSS Inc. SPSS for Windows release 14.0. 2005 Chicago, IL:SPSS Inc. Google Scholar
    • Stevens M. 2005 The role of eyespots as anti-predator mechanisms, principally demonstrated in the Lepidoptera. Biol. Rev. 80, 573–588.doi:10.1017/S1464793105006810. . Crossref, PubMed, ISIGoogle Scholar
    • Stevens M. 2007 Predator perception and the interrelation between different forms of protective coloration. Proc. R. Soc. B. 274, 1457–1464.doi:10.1098/rspb.2007.0220. . Link, ISIGoogle Scholar
    • Stevens M& Cuthill I.C. 2006 Disruptive coloration, crypsis and edge detection in early visual processing. Proc. R. Soc. B. 273, 2141–2147.doi:10.1098/rspb.2006.3556. . Link, ISIGoogle Scholar
    • Stevens, M., Cuthill, I. C., Parraga, C. A. & Troscianko, T. 2006a The effectiveness of disruptive coloration as a concealment strategy. In Progress in brain research, vol. 155 (eds J.-M. Alonso, S. Macknik, L. Martinez, P. Tse & S. Martinez-Conde), pp. 49–64. Amsterdam, The Netherlands: Elsevier. Google Scholar
    • Stevens M, Cuthill I.C, Windsor A.M.M& Walker H.J Disruptive contrast in animal camouflage. Proc. R. Soc. B. 273, 2006b 2433–2438.doi:10.1098/rspb.2006.3614. . Link, ISIGoogle Scholar
    • Stevens M, Hopkins E, Hinde W, Adcock A, Connolly Y, Troscianko T& Cuthill I.C. 2007 Field experiments on the effectiveness of ‘eyespots’ as predator deterrents. Anim. Behav. 74, 1215–1227.doi:10.1016/j.anbehav.2007.01.031. . Crossref, ISIGoogle Scholar
    • Thayer G.H Concealing-coloration in the animal kingdom: an exposition of the laws of disguise through color and pattern: being a summary of Abbott H. Thayer's discoveries. 1909 New York, NY:Macmillan. Google Scholar
    • Zar J.H Biostatistical analysis. 4th edn. 1999 Upper Saddle River, NJ:Prentice-Hall. Google Scholar