[en] Primates, the most colorful mammalian radiation, have previously served as an interesting model to test the functions and evolutionary drivers of variation in eye color. We assess the contribution of photo-regulatory and communicative functions to the external eye appearance of nine macaque species representing all the branches of their radiation. Macaques' well described social structure and wide geographical distribution make them interesting to explore. We find that (1) the posterior option of the anterior eyeball is more pigmented closer to the equator, suggesting photoprotective functions. We also find that (2) the temporal side of the eyeball is more heavily pigmented than the nasal side. This suggests that eyeball pigmentation in macaques is distributed to reduce damage to the corneal limbus. The inclusion of a translocated population of M. fuscata in our analyses also suggests that external eye appearance may change quickly, perhaps owing to phenotypic plasticity. We find no evidence that communicative functions drive variation in external eye appearance in macaques. These results suggest that the amount of light in a species' environment drives variation in eye coloration across macaque species. Furthermore, the geographical distribution of macaques hints at important factors that have yet to be accounted for, such as the reflectivity of the terrain a given species inhabits.
Disciplines :
Environmental sciences & ecology
Author, co-author :
Perea-García, Juan Olvido; Department of Biological Sciences, National University of Singapore, Singapore, Singapore. juan.olvido@gmail.com ; Center for Language Evolution Studies, Nicolaus Copernicus University, Toruń, Poland. juan.olvido@gmail.com
Massen, Jorg J M; Animal Behaviour and Cognition, Department of Biology, Utrecht University, Utrecht, The Netherlands
Ostner, Julia; Department Behavioral Ecology, JFB Institute for Zoology and Anthropology, Georg-August University, Kellnerweg 6, 37077, Göttingen, Goettingen, Germany ; Research Group Primate Social Evolution, German Primate Center Leibniz Institute for Primate Research, Goettingen, Germany ; Leibniz Science Campus Primate Cognition, Goettingen, Germany
Schülke, Oliver; Department Behavioral Ecology, JFB Institute for Zoology and Anthropology, Georg-August University, Kellnerweg 6, 37077, Göttingen, Goettingen, Germany ; Research Group Primate Social Evolution, German Primate Center Leibniz Institute for Primate Research, Goettingen, Germany ; Leibniz Science Campus Primate Cognition, Goettingen, Germany
Castellano-Navarro, Alba; Ethology and Animal Welfare Section, Universidad Cardenal Herrera-CEU, CEU Universities, Tirant lo Blanc 8, Alfara del Patriarca, Valencia, 46115, Spain ; Institute of Biology, Leipzig University, Leipzig, Germany ; Unit of Research SPHERES, University of Liège, Liège, Belgium
Gazagne, Eva ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Biologie du comportement - Ethologie et psychologie animale ; Université de Liège - ULiège > Sphères ; Conservation Ecology Program, King Mongkut's University of Technology, Bangkhuntien, Thailand
José-Domínguez, Juan Manuel; Conservation Ecology Program, King Mongkut's University of Technology, Bangkhuntien, Thailand ; Physical Anthropology Laboratory, Department of Legal Medicine, Toxicology and Physical Anthropology, University of Granada, Granada, Spain
Beltrán-Francés, Víctor; Fundació Universitat de Girona, Innovació I Formació, Girona, Spain
Kaburu, Stefano; School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottingham, NG25 0QF, UK
Ruppert, Nadine; School of Biological Sciences, Universiti Sains Malaysia, Gelugor, 11800, Pulau Pinang, Malaysia ; Malaysian Primatological Society, Kulim, 09000, Kedah, Malaysia
Micheletta, Jérôme; Department of Psychology, Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK
Gupta, Shreejata; Laboratoire de Psychologie Cognitive (LPC), Laboratoire Parole et Langage (LPL), CNRS, Aix-Marseille Université, Marseille, France
Majolo, Bonaventura; School of Psychology, University of Lincoln, Lincoln, UK
Maréchal, Laëtitia; School of Psychology, University of Lincoln, Lincoln, UK
Pflüger, Lena S; Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, Vienna, 1030, Austria ; Wildlife Research Center, Kyoto University, 41-2 Kanrin Aichi, Inuyama, 484-8506, Japan
Böhm, Pia M; Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, Vienna, 1030, Austria
Bourjade, Marie; CLLE, Université de Toulouse, CNRS, Toulouse, France ; Uaso Ngiro Baboon Project, Nairobi, Kenya
Duran, Elif; Department of Psychology, Izmir University of Economics, Izmir, Turkey
Hobaiter, Catherine; School of Psychology, University of St Andrews, Fife, Scotland, UK
Monteiro, Antónia; Department of Biological Sciences, National University of Singapore, Singapore, Singapore. antonia.monteiro@nus.edu.sg ; Science division, Yale-NUS College, Singapore, Singapore. antonia.monteiro@nus.edu.sg
DFG - Deutsche Forschungsgemeinschaft NRF - National Research Foundation Singapore
Funding text :
We would like to thank Aur\u00E9lie Albert-Daviaud for her photographs of M. leonina. This research was supported by a SINGA scholarship awarded to JOPG by A*STAR, and by National Research Foundation (NRF) Singapore, under its NRF-Investigatorship programme (award NRF-NRFI05-2019-0006) and NRF-CRP programme (award: NRF-CRP20-2017-0001). JO and OS were supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), Project-ID 454648639 in SFB 1528 \u2013 Cognition of Interaction.
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