Abstract
‘Cry for help’ hypothesis predicts that attraction of predators with chemical or visual cues can decrease insect damage of plants. Visual cues involve changes in photosynthetic activity and the reflectance of leaves, and there is some evidence that birds may use these changes as foraging cues. However, changes in the visual properties of leaves have not been quantified and it is not known how birds see these changes. We also presented and tested a new ‘reduction in camouflage’ hypothesis (not mutually exclusive with cry for help) stating that herbivore-mediated changes in leaf colour can increase the conspicuousness of herbivore against leaves. To define changes in the visual properties of leaves, their detectability to birds, and whether these changes affect the conspicuousness of herbivore, we manipulated the level of herbivory in silver birch trees (Betula pendula) with autumnal moth (Epirrita autumnata) larvae, and used blue tit (Cyanistes caeruleus) vision models to images of leaves and larvae. Hue, luminance (lightness), contrast, light transmission, chlorophyll content, photosynthetic activity and water content of the leaves were compared between herbivore-damaged and control trees. The leaves of herbivore-damaged trees had a decreased chlorophyll a concentration, increased contrast and they reflected more longer wavelengths. However, these changes are likely not obvious to birds. In contrast to our expectation, there were only minor differences in conspicuousness of larvae against the leaves of damaged trees, which may be very subtle to predator vision. Nevertheless, according to visual models, larvae should be easily detectable to birds from both herbivore-damaged and control trees.
Significance statement
Herbivory affects photosynthetic machinery and light reflectance of leaves, and may thus provide visual foraging cues to birds, although it is not known how these changes appear to birds. We also hypothesized that the changes in leaves may reduce the camouflage of the herbivore. After applying herbivore treatment and using the avian vision models, we found that the leaves of herbivore damage may cause the leaves to appear to birds with higher contrast and greener or a more yellowish colour than control leaves. In addition, although the herbivore was visible to birds, it was slightly less conspicuous when on damaged trees, indicating that the herbivore can be adapted to changes in the food plant. Our results indicate that herbivory causes changes visual properties of leaves, but these changes are likely not obvious to birds.
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References
Allen WL, Baddeley R, Cuthill CI, Scott-Samuel NE (2012) A quantitative test of the predicted relationship between countershading and lighting environment. Am Nat 180:762–776
Amo L, Jansen JJ, van Dam NM, Dicke M, Visser ME (2013) Birds exploit herbivore-induced plant volatiles to locate herbivorous prey. Ecol Lett 16:1348–1355
Amo L, Dicke M, Visser ME (2016) Are naive birds attracted to herbivore-induced plant defences? Behaviour 153:353–366
Birkett MA, Chamberlain K, Guerrieri E, Pickett JA, Wadhams LJ, Yasuda T (2003) Volatiles from whitefly-infested plants elicit a host-locating response in the parasitoid, Encarsia formosa. J Chem Ecol 29:1589–1600
Bond AB, Kamil AC (2006) Spatial heterogeneity, predator cognition, and the evolution of color polymorphism in virtual prey. Proc Natl Acad Sci USA 103:3214–3219
Canfield MR, Chang S, Pierce NE (2009) The double cloak of invisibility: phenotypic plasticity and larval decoration in a geometrid moth, Synchlora frondaria, across three diet treatments. Ecol Entomol 34:412–414
Cazetta E, Schaefer HM, Galetti M (2009) Why are fruits colorful? The relative importance of achromatic and chromatic contrasts for detection by birds. Evol Ecol 23:233–244
Cott HB (1940) Adaptive coloration in animals. Methuen, London
Cuthill IC (2006) Color perception. In: Hill GE, McGraw KJ (eds) Bird coloration, mechanisms and measurements. Harvard University Press, Cambridge, pp 3–40
Edmunds M (1990) Evolution of cryptic coloration. In: Evans DL, Schmidt JO (eds) Insect defenses: adaptive mechanisms and strategies of prey and predators. State University of New York Press, Albany, pp 3–21
Edmunds M, Dewhirst RA (1994) The survival value of countershading with wild birds as predators. Biol J Linn Soc 51:447–452
Endler JA (1978) A predator’s view of animal colour patterns. Evol Biol 11:319–364
Endler JA (1984) Progressive background in moths, and a quantitative measure of crypsis. Biol J Linn Soc 22:187–231
Endler JA, Mappes J (2004) Predator mixes and the conspicuousness of aposematic signals. Am Nat 163:532–547
Endler JA, Mielke PW (2005) Comparing entire colour patterns as birds see them. Biol J Linn Soc 86:405–431
Evans SR, Hinks AE, Wilkin TA, Sheldon BC (2010) Age, sex and beauty: methodological dependence of age- and sex-dichromatism in the great tit Parus major. Biol J Linn Soc 101:777–796
Fleishman LJ, Perez CW, Yeo AI, Cummings KJ, Dick S, Almonte E (2016) Perceptual distance between colored stimuli in the lizard Anolis sagrei: comparing visual system models to empirical results. Behav Ecol Sociobiol 70:541–555
Gates DM (1980) Biophysical ecology. Springer-Verlag, New York
Greenwood JJD, Cotton PA, Wilson DA (1989) Frequency-dependent selection on aposematic prey: some experiments. Biol J Linn Soc 36:213–226
Hart NS (2001) The visual ecology of avian photoreceptors. Prog Retin Eye Res 20:675–703
Hart NS, Vorobyev M (2005) Modelling oil droplet absorption spectra and spectral sensitivities of bird cone photoreceptors. J Comp Physiol A 191:381–392
Hart NS, Partridge JC, Cuthill IC, Bennett ATD (2000) Visual pigments, oil droplets, ocular media and cone photoreceptor distribution in two species of passerine bird: the blue tit (Parus caeruleus L.) and the blackbird (Turdus merula L.) J Comp Physiol A 186:375–387
Heimonen K, Valtonen A, Kontunen-Soppela S, Keski-Saari S, Rousi M, Oksanen E, Roininen H (2015) Colonization of a host tree by herbivorous insects under a changing climate. Oikos 124:1013–1022
Hilker M, Kobs C, Varma M, Schrank K (2002) Insect egg deposition induces Pinus sylvestris to attract egg parasitoids. J Exp Biol 205:455–461
Houston AI, Stevens M, Cuthill IC (2007) Animal camouflage: compromise or specialize in a 2 patch-type environment? Behav Ecol 18:769–775
Hussain A, Razaq M, Shahzad W, Mahmood K, Khan FZA (2014) Influence of aphid herbivory on the photosynthetic parameters of Brassica campestris at Multan, Punjab, Pakistan. J Biodivers Environ Sci 5:410–416
Inskeep WP, Bloom PR (1985) Extinction coefficients of chlorophyll a and b in N,N-dimethylformamide and 80% acetone. Plant Physiol 77:483–485
Jokinen KJ, Honkanen J, Seppänen P, Törmälä T (1991) Biotechnology of the silver birch (Betula pendula Roth). Agro Food Ind Hi Tech 2:23–26
Kelber A, Osorio D (2010) From spectral information to animal colour vision: experiments and concepts. Proc R Soc Lond B 277:1617–1625
Kemp DJ, Herberstein ME, Fleishman LJ, Endler JA, Bennett ATD, Dyer AG, Hart NS, Marshall J, Whiting MJ (2015) An integrative framework for the appraisal of coloration in nature. Am Nat 185:705–724
Kenward MG, Roger JH (2009) An improved approximation to the precision of fixed effects from restricted maximum likelihood. Comput Stat Data Anal 53:2583–2595
Kessler A, Baldwin IT (2001) Defensive function of herbivore-induced plant volatile emissions in nature. Science 291:2141–2144
Kiltie RA (1988) Countershading: universally deceptive or deceptively universal? Trends Ecol Evol 3:21–23
Komdeur J, Oorebeek M, van Overveld T, Cuthill IC (2005) Mutual ornamentation, age, and reproductive performance in the European starling. Behav Ecol 16:805–817
Koponen S (1983) Phytophagous insects of birch foliage in northernmost woodlands of Europe and eastern North America. Nordicana 47:165–176
Korpita T, Gómez S, Orians CM (2014) Cues from a specialist herbivore increase tolerance to defoliation in tomato. Funct Ecol 28:395–401
Koski T-M, Laaksonen T, Mäntylä E, Ruuskanen S, Li T, Girón-Calva PS, Huttunen L, Blande JD, Holopainen JK, Klemola T (2015) Do insectivorous birds use volatile organic compounds from plants as olfactory foraging cues? Three experimental tests. Ethology 121:1131–1144
Krause GH, Weis E (1991) Chlorophyll fluorescence and photosynthesis—the basics. Annu Rev Plant Physiol 42:313–349
Lindstedt C, Huttunen H, Kakko M, Mappes J (2011) Disengtangling the evolution of weak warning signals: high detection risk and low production costs of chemical defences in gregarious pine sawfly larvae. Evol Ecol 25:1029–1046
Lovell PG, Tolhurst DJ, Parraga CA, Baddeley R, Leonards U, Troscianko J (2005) Stability of the color-opponent signals under changes of illuminant in natural scenes. J Opt Soc Am A 22:2060–2071
Maier EJ, Bowmaker JK (1993) Color-vision in the passeriform bird, Leiothrix lutea—correlation of visual pigment absorbency and oil droplet transmission with spectral sensitivity. J Comp Physiol A 172:295–301
Mäntylä E, Klemola T, Haukioja E (2004) Attraction of willow warblers to sawfly-damaged mountain birches: novel function of inducible plant defences? Ecol Lett 7:915–918
Mäntylä E, Alessio GA, Blande JD, Heijari J, Holopainen JK, Laaksonen T, Piirtola P, Klemola T (2008a) From plants to birds: higher avian predation rates in trees responding to insect herbivory. PLoS One 3:e2832
Mäntylä E, Klemola T, Sirkiä P, Laaksonen T (2008b) Low light reflectance may explain the attraction of birds to defoliated trees. Behav Ecol 19:325–330
Mäntylä E, Blande JD, Klemola T (2014) Does application of methyl jasmonate to birch mimic herbivory and attract insectivorous birds in nature? Arthropod Plant Interact 8:143–153
Mäntylä E, Kleier S, Kipper S, Hilker M (2017) The attraction of insectivorous tit species to herbivore-damaged Scots pines. J Ornithol 158:479–491
Merilaita S, Dimitrova M (2014) Accuracy of background matching and prey detection: predation by blue tits indicates intense selection for highly matching prey colour pattern. Funct Ecol 28:1208–1215
Merilaita S, Stevens M (2011) Crypsis through background matching. In: Merilaita S, Stevens M (eds) Animal camouflage: mechanisms & function. Cambridge University Press, Cambridge, pp 17–33
Merilaita S, Tuomi J, Jormalainen V (1999) Optimization of cryptic coloration in heterogeneous habitats. Biol J Linn Soc 67:151–161
Moreno J (1981) Feeding niches of woodland birds in a montane coniferous forest in central Spain during winter. Ornis Scand 12:148–159
Nokelainen O, Hegna RH, Reudler JH, Lindstedt C, Mappes J (2012) Trade-off between warning signal efficacy and mating success in the wood tiger moth. Proc R Soc Lond B 279:257–265
Noor MAF, Parnell RS, Grant BS (2008) A reversible color polyphenism in American peppered moth (Biston betularia cognataria) caterpillars. PLoS One 3:e3142
Oleksyn J, Karolewski P, Giertych MJ, Zytkowiak R, Reich PB, Tjoelker MG (1998) Primary and secondary host plants differ in leaf-level photosynthetic response to herbivory: evidence from Alnus and Betula grazed by the alder beetle, Agelastica alni. New Phytol 140:239–249
Osorio D, Vorobyev M (2005) Photoreceptor spectral sensitivities in terrestrial animals: adaptations for luminance and colour vision. Proc R Soc Lond B 272:1745–1752
Osorio D, Miklosi A, Gonda Z (1999) Visual ecology and perception of coloration patterns by domestic chicks. Evol Ecol 13:673–689
Pike TW (2011) Using digital cameras to investigate animal colouration: estimating sensor sensitivity functions. Behav Ecol Sociobiol 65:849–858
Poteri M, Helander ML, Saikkonen K, Elamo P (2001) Effect of Betula pendula clone and leaf age on Melampsoridium betulinum rust infection in a field trial. For Pathol 31:177–185
Ramachandran VS (1988) Perceiving shape from shading. Sci Am 259:76–83
Renoult JP, Kelber A, Schaefer HM (2015) Colour spaces in ecology and evolutionary biology. Biol Rev 92:292–315
Retuerto R, Fernandez-Lema B, Rodriguez R, Obeso JR (2004) Increased photosynthetic performance in holly trees infested by scale insects. Funct Ecol 18:664–669
Rowland HM, Speed MP, Ruxton GD, Edmunds M, Stevens M, Harvey IF (2007) Countershading enhances cryptic protection: an experiment with wild birds and artificial prey. Anim Behav 74:1249–1258
Rowland HM, Cuthill IC, Harvey IF, Speed MP, Ruxton GD (2008) Can’t tell the caterpillars from the trees: countershading enhances survival in a woodland. Proc R Soc Lond B 275:2539–2545
Sandre S-L, Tammaru T, Esperk T, Julkunen-Tiitto R, Mappes J (2007) Carotenoid-based colour polyphenism in a moth species: search for fitness correlates. Entomol Exp Appl 124:269–277
Sandre S-L, Stevens M, Mappes J (2010) The effect of predator appetite, prey warning coloration and luminance on predator foraging decisions. Behaviour 147:1121–1143
Sandre S-L, Kaasik A, Eulitz U, Tammaru T (2013) Phenotypic plasticity in a generalist insect herbivore with the combined use of direct and indirect cues. Oikos 122:1626–1635
Schaefer HM, Ruxton GD (2011) Plant-animal communication. Oxfor University Press, New York
Schneider CA, Rasband WS, Eliceiri KW (2012) NIH Image to ImageJ: 25 years of image analysis. Nat Methods 9:671–675
Siddiqi A, Cronin TW, Loew ER, Vorobyev M, Summers K (2004) Interspecific and intraspecific views of color signals in the strawberry poison frog Dendrobates pumilio. J Exp Biol 207:2471–2485
Silvonen K, Top-Jensen M, Fibiger M (2014) Suomen päivä-ja yöperhoset—maastokäsikirja (a field guide to the butterflies and moths of Finland). Bugbook Publishing, Oestermarie
Spottiswoode CN, Stevens M (2011) How to evade a coevolving brood parasite: egg discrimination versus egg variability as host defences. Proc R Soc Lond B 278:3566–3573
Steinbrenner AD, Gómez S, Osorio S, Fernie AR, Orians CM (2011) Herbivore-induced changes in tomato (Solanum lycopersicum) primary metabolism: a whole plant perspective. J Chem Ecol 37:1294–1303
Stevens M (2007) Predator perception and the interrelation between different forms of protective coloration. Proc R Soc Lond B 274:1457–1464
Stevens M (2011) Avian vision and egg colouration: concepts and measurements. Avian Biol Res 4:168–184
Stevens M, Cuthill IC (2006) Disruptive coloration, crypsis and edge detection in early visual processing. Proc R Soc Lond B 273:2141–2147
Stevens M, Parraga CA, Cuthill IC, Partridge JC, Troscianko TS (2007) Using digital photography to study animal coloration. Biol J Linn Soc 90:211–237
Stevens M, Stoddard MC, Higham JP (2009) Studying primate color: towards visual system-dependent methods. Int J Primatol 30:893–917
Stevens M, Lown AE, Wood LE (2014) Colour change and camouflage in juvenile shore crabs Carcinus maenas. Front Ecol Evol 2:14
Stobbe N, Dimitrova M, Merilaita S, Schaefer HM (2009) Chromaticity in the UV/blue range facilitates the search for achromatically background-matching prey in birds. Philos Trans R Soc B 364:511–517
Takabayashi J, Dicke M (1996) Plant-carnivore mutualism through herbivore-induced carnivore attractants. Trends Plant Sci 1:109–113
Takahashi S, Murata N (2008) How do environmental stresses accelerate photoinhibition? Trends Plant Sci 13:178–182
Thayer AH (1896) The law which underlies protective coloration. Auk 13:124–129
Thayer GH (1909) 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 disclosures by Gerald H. Thayer with an introductory essay by A.H. Thayer. MacMillan, New York
Thurman TJ, Seymoure BM (2015) A bird’s eye view of two mimetic tropical butterflies: coloration matches predator’s sensitivity. J Zool 298:159–168
Troscianko J, Stevens M (2015) Image calibration and analysis toolbox—a free software suite for objectively measuring reflectance, colour and pattern. Methods Ecol Evol 6:1320–1331
Troscianko J, Wilson-Aggarwal J, Stevens M, Spottiswoode CN (2016) Camouflage predicts survival in ground-nesting birds. Sci Rep 6:8
Turlings TCJ, Tumlinson JH, Lewis WJ (1990) Exploitation of herbivore-induced plant odors by host-seeking parasitic wasps. Science 250:1251–1253
Tyystjärvi E (2008) Photoinhibition and photodamage of the oxygen evolving manganese cluster. Coord Chem Rev 252:361–376
van Wijk M, De Bruijn PJA, Sabelis MW (2008) Predatory mite attraction to herbivore-induced plant odors is not a consequence of attraction to individual herbivore-induced plant volatiles. J Chem Ecol 34:791–803
Vorobyev M, Osorio D (1998) Receptor noise as a determinant of colour thresholds. Proc R Soc Lond B 265:351–358
Vorobyev M, Osorio D, Bennett ATD, Marshall NJ, Cuthill IC (1998) Tetrachromacy, oil droplets and bird plumage colours. J Comp Physiol A 183:621–633
Zangerl AR, Hamilton JG, Miller TJ, Crofts AR, Oxborough K, Berenbaum MR, de Lucia EH (2002) Impact of folivory on photosynthesis is greater than the sum of its holes. Proc Natl Acad Sci USA 99:1088–1091
Acknowledgements
We thank Päivi M. Sirkiä for her valuable comments on the manuscript and Mariel Mansoniemi for conducting the photosynthesis and fluorescence measurements. We are also grateful to the anonymous reviewers; their comments significantly improved the manuscript. This study was financially supported by the University of Turku Graduate School (T-MK) and by the Academy of Finland (grant 218086 to TL; grants 259075 and 271832 to ET).
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Koski, TM., Lindstedt, C., Klemola, T. et al. Insect herbivory may cause changes in the visual properties of leaves and affect the camouflage of herbivores to avian predators. Behav Ecol Sociobiol 71, 97 (2017). https://doi.org/10.1007/s00265-017-2326-0
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DOI: https://doi.org/10.1007/s00265-017-2326-0