UV-Based Dewlap Color Correlates With Bite Force in the Brown Anole, Norops sagrei

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Weapon strength should be conveyed in correlated visual signals if they confer advantage to visual signal senders and receivers. This should especially be true in species that experience strong male-male competition. Anolis lizards are well known for their territorial behaviors in which males display visually striking and colorful dewlaps, and for which male-male competition is thought to be a very strong selective force. In many anoles, biting is used by males to pacify females during copulation, as well as inflict wounds on competing males. Biting is generally thought to be an important male behavior because it can create a painful wound that may ultimately affect the recipients fitness by causing death. We analyzed aspects of carotenoid and pterin based dewlap color in relation to male body size, dewlap size and bite force in the Brown Anole (Norops sagrei). We found that male body size positively related to ultra-violet (uv) dewlap color but did not relate to dewlap size or bite force. We assessed male dewlap colorfulness by creating a composite score that accounted for an individual’s dewlap size, percent of dewlap area colored by pterins vs. carotenoids, and the saturation of color produced by each pigment in different dewlap regions. Our results showed that bite force related positively with dewlap uv color scores but did not relate to dewlap size. These results suggest that ultra-violet dewlap color may convey information about bite force, and that carotenoid pigments may advertise weapon strength in Norops sagrei.


Society for Integrative and Comparative Biology Annual Meeting (SICB)


Phoenix, AZ