Boldness, Dominance, and Territoriality in the Color Polymorphic Tree Lizard, Urosaurus ornatus

Abstract

Social dynamics in territorial species often reflect underlying variation in aggression and other aspects of social dominance among individuals. In ornate tree lizards (Urosaurus ornatus), males differing in dewlap color differ in social dominance: while blue males are the dominant, aggressive morph and always territorial, yellow males tend to exhibit a less‐aggressive satellite behavioral tactic. However, in habitats with fewer available territorial resources, yellow males defend territories and increase in relative abundance. These observations suggest that consideration of social dominance alone may be insufficient to explain U. ornatus' territorial dynamics in the wild. Here, we tested how both dominance and another important behavioral trait, boldness, contribute to the outcome of territorial disputes in tree lizards. We recorded the territorial behavior of blue and yellow male tree lizards (entered in pairs) in an experimental arena. At the end of each trial, we then approached each male and recorded whether it fled (shy) or not (bold) in response to our approach. As expected, dominant blue males exploited the higher quality perch more often than yellow males. However, when approached by a simulated predator, blue males were more likely to flee than yellow males. Thus, while blue males are more dominant, yellow is likely the bolder morph. As a result, this morph may be better equipped to defend territories in riskier environments. We conclude that although dominance asymmetries may predictably drive initial territorial interactions among competing males, variation in other behaviors (like boldness) may perturb the long‐term outcome of these interactions across variable environments.

Density‐dependent habitat selection predicts fitness and abundance in a small lizard

“…The isodar was straight over a wide range of densities and demonstrated that tree lizards preferred the wash habitat. Tree lizards are very territorial (Carpenter 1995, Taylor andLattanzio 2016), so we were expecting a curved isodar. It is possible that curvature in the isodar may only become apparent at very high densities, once the habitat is completely saturated with territories.…”

Lack of spermatogenic variation in a polymorphic lizard, Sceloporus aeneus (Squamata: Phrynosomatidae)

“…In lizards, male morphs differ in several traits including behaviour (Stephenson, 2010;Taylor & Lattanzio, 2016; Yewers, Pryke, & Stuart-Fox, 2016), morphology (Huyghe, Vanhooydonck, Herrel, Tadic, & Van Damme, 2007;Stephenson, 2010), territory (Zamudio & Sinervo, 2000), parasitic load (Megía-Palma et al, 2018) and physiology (LaDage, Riggs, Sinervo, & Pravosudov, 2009;Stephenson, 2010). However, different comparisons among morphs did not reveal any significant difference including morphometry (Meyers, Irschick, Vanhooydonck, & Herrel, 2006;Sacchi et al, 2007;Yewers, Jessop, & Stuart-Fox, 2017), total of number of offspring and their survivorship (Zamudio & Sinervo, 2000), performance (Huyghe et al, 2007;Meyers et al, 2006), behaviour, microhabitat use, thermoregulation (Huyghe et al, 2007) and/ or spermatogenic output (this study).…”

“…Male polymorphisms have been reported in multiple genera within Phrynosomatidae including, but not limited to the following: Uta (Sinervo & Lively, 1996), Urosaurus (Taylor & Lattanzio, 2016) and Sceloporus (Rand, 1990). The Sceloporus genus is one of the most diverse genera of squamates (Wiens & Reeder, 1997) and exhibits a wide array of morphological variation, specifically sexually dimorphic characters (Jiménez-Arcos, Sanabria-Urbán, & Cueva del Castillo, 2017).…”

Male throat colour polymorphism is related to differences in space use and in habitat selection in tree lizards

“…Orange-throated males can be nomadic or sedentary, depending on resource levels (Moore et al, 1998), and do not defend territories (Moore et al, 1998). Males with yellow or green throats live in between the territories of blue-throated males and sneak copulations with females (Taylor & Lattanzio, 2016). Male throat colour is correlated with differences in aggression (Taylor & Lattanzio, 2016), diet (Lattanzio & Miles, 2016) and microhabitat use (Lattanzio & Miles, 2014).…”

“…Males with yellow or green throats live in between the territories of blue-throated males and sneak copulations with females (Taylor & Lattanzio, 2016). Male throat colour is correlated with differences in aggression (Taylor & Lattanzio, 2016), diet (Lattanzio & Miles, 2016) and microhabitat use (Lattanzio & Miles, 2014). Thus, testing for differences in habitat selection between male throat colour phenotypes will improve our ability to predict space use and will help determine whether habitat selection contributes to the maintenance of the throat colour polymorphism.…”