5CEREEP-Ecotron Ile de France (UMS 3194) (CNRS / ENS UMS 3194,
Centre de recherche en écologie expérimentale et prédictive - Ecotron Ile de France,
École Normale Supérieure, Rue du Château, 77140 St-Pierre-les-Nemours - France)
Abstract : The understanding of developmental patterns of body coloration is challenging because of the multicomponent nature of color signals and the multiple selective pressures acting upon them, which further depend on the sex of the bearer and area of display. Pigmentary colors are thought to be strongly involved in sexual selection, while structural colors are thought to generally associate with conspecifics interactions and improve the discrimination of pigmentary colors. Yet, it remains unclear whether age dependency in each color component is consistent with their potential function. Here, we address lifelong ontogenetic variation in three color components (i.e. UV, pigmentary, and skin background colors) in a birth cohort of common lizards Zootoca vivipara across three ventral body regions (i.e. throat, chest, and belly). All three color components developed sexual dichromatism, with males displaying stronger pigmentary and UV colors but weaker skin background coloration than females. The development of color components led to a stronger sexual dichromatism on the concealed ventral region than on the throat. No consistent signs of late‐life decay in color components were found except for a deceleration of UV reflectance increase with age on the throat of males. These results suggest that body color components in common lizards are primarily nonsenescent sexual signals, but that the balance between natural and sexual selection may be altered by the conspicuousness of the area of display. These results further support the view that skin coloration is a composite trait constituted of multiple color components conveying multiple signals depending on age, sex, and body location.
Willem Bonnaffé, Mélissa Martin, Marianne Mugabo, Sandrine Meylan, Jean‐françois Le Galliard. Ontogenetic trajectories of body coloration reveal its function as a multicomponent nonsenescent signal. Ecology and Evolution, Wiley Open Access, 2018, 8 (24), pp.12299-12307. ⟨10.1002/ece3.4369⟩. ⟨hal-01978736⟩