Skip to main content

Faculty of Health and Life Sciences

Dr Jolyon Troscianko

Dr Jolyon Troscianko

Senior Lecturer

 +44 1326 259023

 Stella Turk Building Stella Turk - lower ground flo


University of Exeter, Penryn Campus, Penryn, TR10 9FE


I’m a visual ecologist, and my research covers themes such as the impact of artificial light on moths, how land use and scene properties affect camouflage in ground nesting birds.

Broad research specialisms:

  • Sensory ecology & evolution
  • Camouflage
  • Sensory modelling: I enjoy developing new technology and code to “see” through the visual systems of different animals.
  • Animal Behaviour & Learning

For more information, see my website.


2005 BA, Oxford
2006 MSc, Oxford
2012 PhD, Birmingham


Back to top


Journal articles

Caves E, Troscianko J, Kelley L (In Press). A customizable, low-cost optomotor apparatus: a powerful tool for behaviourally measuring visual capability. Methods in Ecology and Evolution
Troscianko J, Briolat ES, Gaston KJ, Bennie J, Rosenfeld EJ (In Press). Artificial nighttime lighting impacts visual ecology links between flowers, pollinators and predators. Nature Communications
Price N, Green S, Troscianko J, Tregenza T, Stevens M (In Press). Background matching and disruptive coloration as habitat-specific strategies for camouflage. Scientific Reports
Heathcote R, Darden S, Troscianko J, Lawson MRM, Brown AM, Laker PR, Naisbett-Jones LC, MacGregor HEA, Ramnarine I, Croft DP, et al (In Press). Dynamic eye colour as an honest signal of aggression. Current Biology
Stevens M, Broderick AC, Godley BJ, Lown AE, Troscianko J, Weber N, Weber SB (In Press). Phenotype-Environment Matching in Sand Fleas. Biology Letters
Dalbosco Dell’Aglio D, Troscianko J, McMillan WO, Stevens M, Jiggins CD (In Press). The appearance of mimetic Heliconius butterflies to predators and conspecifics. Evolution
Kelley L, Troscianko J (In Press). The evolution of patterning during movement in a large-scale citizen science game. Proceedings of the Royal Society B: Biological Sciences
Troscianko J, Osorio D (2023). A model of colour appearance based on efficient coding of natural images. PLoS Comput Biol, 19(6). Abstract.  Author URL.
Bullough K, Gaston KJ, Troscianko J (2023). Artificial light at night causes conflicting behavioural and morphological defence responses in a marine isopod. Proc Biol Sci, 290(2000). Abstract.  Author URL.
Jolkkonen J, Gaston KJ, Troscianko J (2023). Artificial lighting affects the landscape of fear in a widely distributed shorebird. Communications Biology, 6(1). Abstract.
Dixit T, Choi GPT, Al-Mosleh S, Lund J, Troscianko J, Moya C, Mahadevan L, Spottiswoode CN (2023). Combined measures of mimetic fidelity explain imperfect mimicry in a brood parasite-host system. Biol Lett, 19(2). Abstract.  Author URL.
Hancock GRA, Grayshon L, Burrell R, Cuthill I, Hoodless A, Troscianko J (2023). Habitat geometry rather than visual acuity limits the visibility of a ground-nesting bird's clutch to terrestrial predators. ECOLOGY AND EVOLUTION, 13(9).  Author URL.
Troscianko J (2023). OSpRad: an open-source, low-cost, high-sensitivity spectroradiometer. J Exp Biol, 226(13). Abstract.  Author URL.
Kelley JL, Jessop A-L, Kelley LA, Troscianko J (2023). The role of pictorial cues and contrast for camouflage. Evolutionary Ecology, 37(6), 909-925. Abstract.
Yorzinski JL, Troscianko J, Briolat E, Schapiro SJ, Whitham W (2022). A songbird can detect the eyes of conspecifics under daylight and artificial nighttime lighting. Environmental Pollution, 313, 120000-120000.
Hancock GRA, Troscianko J (2022). CamoEvo: an open access toolbox for artificial camouflage evolution experiments. Evolution, 76(5), 870-882. Abstract.  Author URL.
Whitham W, Schapiro SJ, Troscianko J, Yorzinski JL (2022). Chimpanzee (Pan troglodytes) gaze is conspicuous at ecologically-relevant distances. Sci Rep, 12(1). Abstract.  Author URL.
Sulc M, Hughes AE, Mari L, Troscianko J, Tomasek O, Albrecht T, Jelinek V (2022). Nest sanitation as an effective defence against brood parasitism. ANIMAL COGNITION, 25(4), 991-1002.  Author URL.
Yong L, Croft DP, Troscianko J, Ramnarine IW, Wilson AJ (2022). Sensory-based quantification of male colour patterns in Trinidadian guppies reveals no support for parallel phenotypic evolution in multivariate trait space. Mol Ecol, 31(5), 1337-1357. Abstract.  Author URL.
Whitham W, Schapiro SJ, Troscianko J, Yorzinski JL (2022). The gaze of a social monkey is perceptible to conspecifics and predators but not prey. Proc Biol Sci, 289(1976). Abstract.  Author URL.
Šulc M, Hughes AE, Troscianko J, Štětková G, Procházka P, Požgayová M, Piálek L, Piálková R, Brlík V, Honza M, et al (2021). Automatic identification of bird females using egg phenotype. Zoological Journal of the Linnean Society, 195(1), 33-44.
Massy R, Hawkes WLS, Doyle T, Troscianko J, Menz MHM, Roberts NW, Chapman JW, Wotton KR (2021). Hoverflies use a time-compensated sun compass to orientate during autumn migration. Proceedings of the Royal Society B: Biological Sciences, 288(1959), 20211805-20211805. Abstract.
Troscianko J, Nokelainen O, Skelhorn J, Stevens M (2021). Variable crab camouflage patterns defeat search image formation. Communications Biology, 4, 287-287.
Heathcote RJP, Troscianko J, Darden S, Naisbett-Jones LC, Laker P, Brown AM, Ramnarine IW, Walker J, Croft D (2020). A matador-like predator diversion strategy driven by conspicuous colouration in guppies. Current Biology, 30 (14), 2844-2851.
Young MMI, Winters S, Young C, Weiß BM, Troscianko J, Ganswindt A, Barrett L, Henzi SP, Higham JP, Widdig A, et al (2020). Male characteristics as predictors of genital color and display variation in vervet monkeys. Behavioral Ecology and Sociobiology, 74(2). Abstract.
Jamie GA, Van Belleghem SM, Hogan BG, Hamama S, Moya C, Troscianko J, Stoddard MC, Kilner RM, Spottiswoode CN (2020). Multimodal mimicry of hosts in a radiation of parasitic finches. Evolution, 74(11), 2526-2538. Abstract.  Author URL.
van den Berg C, Troscianko J, Endler JA, Marshall NJ, Cheney KL (2020). Quantitative Colour Pattern Analysis (QCPA): a comprehensive framework for the analysis of colour patterns in nature. METHODS IN ECOLOGY AND EVOLUTION, 11(2), 316-332.  Author URL.
Stephenson JF, Stevens M, Troscianko J, Jokela J (2020). The Size, Symmetry, and Color Saturation of a Male Guppy's Ornaments Forecast His Resistance to Parasites. AMERICAN NATURALIST, 196(5), 597-608.  Author URL.
Šulc M, Troscianko J, Štětková G, Hughes AE, Jelínek V, Capek M, Honza M (2019). Mimicry cannot explain rejection type in a host–brood parasite system. Animal Behaviour, 155, 111-118. Abstract.
Koleček J, Šulc M, Piálková R, Troscianko J, Požgayová M, Honza M, Procházka P (2019). Rufous Common Cuckoo chicks are not always female. Journal of Ornithology, 160(1), 155-163. Abstract.
Hawkes MF, Duffy E, Joag R, Skeats A, Radwan J, Wedell N, Sharma MD, Hosken DJ, Troscianko J (2019). Sexual selection drives the evolution of male wing interference patterns. Proc Biol Sci, 286(1903). Abstract.  Author URL.
Dell’Aglio DD, Troscianko J, Stevens M, McMillan WO, Jiggins CD (2019). The conspicuousness of the toxic<i>Heliconius</i>butterflies across time and habitat. Abstract.
Troscianko J, Skelhorn J, Stevens M (2018). Camouflage strategies interfere differently with observer search images. Proceedings of the Royal Society B: Biological Sciences, 285, 20181386-20181386.
Troscianko J, Skelhorn J, Stevens M (2018). Camouflage strategies interfere differently with observer search images. Proceedings of the Royal Society B: Biological Sciences, 285(1886). Abstract.
Ligon RA, Diaz CD, Morano JL, Troscianko J, Stevens M, Moskeland A, Laman TG, Scholes E (2018). Evolution of correlated complexity in the radically different courtship signals of birds-of-paradise. PLoS Biology, 16, e2006962-e2006962.
Gómez J, Ramo C, Troscianko J, Stevens M, Castro M, Pérez-Hurtado A, Liñán-Cembrano G, Amat JA (2018). Individual egg camouflage is influenced by microhabitat selection and use of nest materials in ground-nesting birds. Behavioral Ecology and Sociobiology, 72, 142-142.
Gómez J, Ramo C, Stevens M, Liñán-Cembrano G, Rendón MA, Troscianko J, Amat JA (2018). Latitudinal variation in biophysical characteristics of avian eggshells to cope with differential effects of solar radiation. Ecology and Evolution, 8, 8019-8029.
Holmes GG, Delferrière E, Rowe C, Troscianko J, Skelhorn J (2018). Testing the feasibility of the startle-first route to deimatism. Sci Rep, 8(1). Abstract.  Author URL.
Abernathy VE, Troscianko J, Langmore NE (2017). Egg mimicry by the Pacific koel: mimicry of one host facilitates exploitation of other hosts with similar egg types. Journal of Avian Biology, 48(11), 1414-1424. Abstract.
Stevens M, Troscianko J, Wilson-Aggarwal JK, Spottiswoode CN (2017). Improvement of individual camouflage through background choice in ground-nesting birds. Nature Ecology and Evolution, 1, 1325-1325.
Koski T-M, Lindstedt C, Klemola T, Troscianko J, Mäntylä E, Tyystjärvi E, Stevens M, Helander M, Laaksonen T (2017). Insect herbivory may cause changes in the visual properties of leaves and affect the camouflage of herbivores to avian predators. Behavioral Ecology and Sociobiology, 31, 97-97.
Troscianko J, Skelhorn J, Stevens M (2017). Quantifying camouflage: how to predict detectability from appearance. BMC Evolutionary Biology, 17, 7-7.
Troscianko J, Wilson-Aggarwal J, Griffiths D, Spottiswoode CN, Stevens M (2017). Relative advantages of dichromatic and trichromatic color vision in camouflage breaking. Behavioral Ecology, 28, 556-556.
Robledo-Ospina LE, Escobar-Sarria F, Troscianko J, Rao D (2017). Two ways to hide: predator and prey perspectives of disruptive coloration and background matching in jumping spiders. BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, 122(4), 752-764.  Author URL.
Medina I, Troscianko J, Stevens M, Langmore NE (2016). Brood Parasitism is Linked to Egg Pattern Diversity within and among Species of Australian Passerines. Am Nat, 187(3), 351-362. Abstract.  Author URL.
Troscianko J, Wilson-Aggarwal J, Stevens M, Spottiswoode CN (2016). Camou age predicts survival in ground-nesting birds. Scientific Reports, 6
Wilson-Aggarwal, Troscianko, Stevens M, Spottiswoode CN (2016). Escape distance in ground-nesting birds differs with individual level of camouflage. The American Naturalist, 188, 231-231.
Duarte A, De Gasperin O, Troscianko J, Kilner RM (2016). Fitness costs associated with building and maintaining the burying beetle's carrion nest. Sci Rep, 6 Abstract.  Author URL.
Troscianko, Wilson-Aggarwal, Spottiswoode CN, Stevens M (2016). Nest covering in plovers: how modifying the visual environment influences egg camouflage. Ecology and Evolution, 6, 7536-7545.
Troscianko J, Rutz C (2015). Activity profiles and hook-tool use of New Caledonian crows recorded by bird-borne video cameras. Biol Lett, 11(12). Abstract.  Author URL.
Burriss R, Troscianko J, Lovell PG, Fulford AJC, Stevens M, Quigley R, Payne J, Saxton TK, Rowland HM (2015). Changes in Women’s Facial Skin Color over the Ovulatory Cycle are Not Detectable by the Human Visual System. PLoS ONE, 10, e0130093-e0130093.
Troscianko J, Stevens M, Skelhorn J (2015). Does Disruptive Camouflage Disrupt Search Image Formation?. PERCEPTION, 44(10), 1239-1240.  Author URL.
Feeney WE, Troscianko J, Langmore NE, Spottiswoode CN (2015). Evidence for aggressive mimicry in an adult brood parasitic bird, and generalized defences in its host. Proc Biol Sci, 282(1810). Abstract.  Author URL.
Troscianko J, Stevens M (2015). Image Calibration and Analysis Toolbox – a free software suite for objectively measuring reflectance, colour and pattern. Methods in Ecology and Evolution, 6, 1320-1331.
Troscianko J (2014). A simple tool for calculating egg shape, volume and surface area from digital images. Ibis, 156(4), 874-878. Abstract.
Arenas LM, Troscianko J, Stevens M (2014). Color contrast and stability as key elements for effective warning signals. Frontiers in Ecology and Evolution, 2
Hughes AE, Troscianko J, Stevens M (2014). Motion dazzle and the effects of target patterning on capture success. BMC Evol Biol, 14 Abstract.  Author URL.
Troscianko J, Lown AE, Hughes AE, Stevens M (2013). Defeating crypsis: detection and learning of camouflage strategies. PLoS One, 8(9). Abstract.  Author URL.
Rutz C, Troscianko J (2013). Programmable, miniature video-loggers for deployment on wild birds and other wildlife. Methods in Ecology and Evolution, 4(2), 114-122. Abstract.
Stevens M, Troscianko J, Spottiswoode CN (2013). Repeated targeting of the same hosts by a brood parasite compromises host egg rejection. Nat Commun, 4 Abstract.  Author URL.
Stevens M, Marshall KLA, Troscianko J, Finlay S, Burnand D, Chadwick SL (2013). Revealed by conspicuousness: Distractive markings reduce camouflage. Behavioral Ecology, 24(1), 213-222. Abstract.
Stevens M, Troscianko J, Marshall KLA, Finlay S (2013). What is camouflage through distractive markings a reply to Merilaita et al. (2013). Behavioral Ecology, 24(5).
Troscianko J, von Bayern AMP, Chappell J, Rutz C, Martin GR (2012). Extreme binocular vision and a straight bill facilitate tool use in New Caledonian crows. Nat Commun, 3 Abstract.  Author URL.
Hughes A, Troscianko J, Tolhurst D, Stevens M (2012). Prey movement and the mechanisms of dazzle coloration. PERCEPTION, 41(10), 1271-1271.  Author URL.
Rutz CR, Bluff LA, Reed N, Troscianko J, Newton J, Inger R, Kacelnik A, Bearhop S (2010). The Ecological Significance of Tool Use in New Caledonian Crows. Science, 329, 1523-1525. Abstract.
Bluff LA, Troscianko J, Weir AAS, Kacelnik A, Rutz C (2010). Tool use by wild New Caledonian crows Corvus moneduloides at natural foraging sites. Proc Biol Sci, 277(1686), 1377-1385. Abstract.  Author URL.
Takahashi T, McDougall C, Troscianko J, Chen W-C, Jayaraman-Nagarajan A, Shimeld SM, Ferrier DEK (2009). An EST screen from the annelid Pomatoceros lamarckii reveals patterns of gene loss and gain in animals. BMC Evol Biol, 9 Abstract.  Author URL.
Troscianko J, Bluff LA, Rutz C (2008). Grass-stem tool use in New Caledonian Crows Corvus moneduloides. Ardea, 96(2), 283-285. Abstract.
Lovell PG, Tolhurst DJ, Párraga CA, Baddeley R, Leonards U, Troscianko J, Troscianko T (2005). Stability of the color-opponent signals under changes of illuminant in natural scenes. J Opt Soc Am a Opt Image Sci Vis, 22(10), 2060-2071. Abstract.  Author URL.
Parraga CA, Troscianko T, Troscianko J, Tolhurst DJ, Leonards U (2003). Spatiochromatic properties of images of fruits and leaves from Kibale Forest, Uganda. Journal of Vision, 3(9). Abstract.
Troscianko T, Baddeley R, Parraga CA, Leonards U, Troscianko J (2003). Visual encoding of green leaves in primate vision. Journal of Vision, 3(9). Abstract.


Lovell PG, Tolhurst DJ, Párraga CA, Baddeley RJ, Leonards U, Troscianko J, Troscianko T (2005). Opponent channel responses to changes in the illuminant of natural scenes for primates and birds.  Author URL.
Troscianko T, Parraga CA, Leonards U, Baddeley RJ, Troscianko J, Tolhurst DJ (2003). Leaves, fruit, shadows, and lighting in kibale forest, Uganda.  Author URL.

Back to top

External Engagement and Impact

Invited lectures

Media Coverage

My research has been covered by numerous media outlets, such as New Scientist and See

my website

for more info.

Back to top

Supervision / Group

Postgraduate researchers

  • George Hancock

Back to top

Office Hours:

Office hours: 14:00 on Mondays or 14:00 on Fridays. Either call me on Teams, or come to my office in Stella Turk and knock on my door. To find my office, enter through the circular sliding doors, turn left, and my office is at the end of the coridor.

Back to top

Edit Profile