The Role of Lateral Blue Spots in Intrasexual Relationships Between Male Iberian Rock‐Lizards, Lacerta monticola

Abstract

Vertebrate males often show breeding colours that may function as reliable signals of status in intrasexual competition. In many lacertid lizards, males show a conspicuous row of small but distinctive blue spots that runs along their body side on the outer margin of the belly. However, no study has examined the role of these blue spots. We first analysed in a field population of the Iberian rock lizard, Lacerta monticola, the relationships between number of blue spots and some morphological traits, which are known to be related to malesÕ fighting ability. The number of spots seems to be an character showing ontogenetic change as large (generally older) males showed more blue spots than small (generally younger) males. Males with a higher body condition also showed a higher number of blue spots. Thus, a higher number of blue spots may be used to signal size, age or body condition. Many contiguous blue spots would result in a visual artefact consisting of a continuous blue band, which might be a reliable size-or condition-dependent signal in some social contexts. We further examined in the laboratory whether male characteristics are related to dominance status. In males with similar body size or age, those with relatively larger heads were more dominant, whereas the number of blue spots was not important. Moreover, the number of blue spots in nature was not related to relative head size. Finally, we experimentally manipulated the presence and the number of blue spots of intruding males, and examined the aggressive response of resident males. Intruder individuals manipulated to cover all their blue spots received a lower amount of aggression. However, males with different numbers of manipulated blue spots received a similar number of aggressive responses. These results suggest that, during agonistic encounters, the presence of blue spots, but not their number, may elicit aggressiveness. Thus, blue spots may serve to identify an individual as an adult male, and to enhance body size of larger males.

Ultraviolet nuptial colour determines fight success in male European green lizards (Lacerta viridis)

“…However, such differences might not be easy and quick to assess for males. Signals advertising fighting ability allow male lizards to assess probability of winning and, therefore, to avoid energetically costly escalated fighting, injuries, and increased predation risk [22,23], and to gain time and energy for other tasks like feeding, mate search or thermoregulation [4]. The role of UV signals in advertising dominance status or aggression has been shown in different taxa [13 -16].…”

Do displays and badges function in establishing the social structure of male toad-headed lizards, Phrynocephalus vlangalii?

“…Display behaviors are also known to predict an individual lizard's aggressiveness and performance capacity (Hover and Jenssen 1976;Brandt 2003;Orrell and Jenssen 2003;Perry et al 2004;Osborne 2005). Individuals exhibiting different social statuses are expected to develop differences in their display behaviors and badges (Zucker 1989;Andersson et al 2002;Lopez et al 2004;McElroy et al 2007).…”

“…In contrast, subordinate individuals employ nonagonistic tactics, such as floater, sneaker or satellite tactics (Waltz 1982;Dominey 1984;Zug et al 2001). Residents and floaters are believed to exhibit differences in their badges and display behaviors, because these traits are correlated with individual social status (Zucker 1989;Andersson et al 2002;Lopez et al 2004;McElroy et al 2007). However, few studies have sought to specifically investigate the roles of badges and displays in the establishment of such social structures.…”

Effects of testosterone on the spatial ecology, coloration, and brain regions in western fence lizards, Sceloporus occidentalis

“…In numerous other species of lizards, coloration signals intrasexual messages (Fresnillo et al, 2015;Baird et al, 2013;López et al, 2004). For instance, adult aggression was reduced towards juvenile spiny-footed lizards (Acanthodactylus erthrurus) with red coloration (Fresnillo et al, 2015).…”

“…For instance, adult aggression was reduced towards juvenile spiny-footed lizards (Acanthodactylus erthrurus) with red coloration (Fresnillo et al, 2015). In Iberian rock lizards (Lacerta monticola), adult males intruders with a lower number of abdominal blue dots received less aggressive behaviors than residents (López et al, 2004). Likewise, smaller adult Algerian sand lizards lacking nuptial coloration expressed in larger, more dominant males received higher agnostic behaviors then when nuptial coloration was experimentally added (Martín and Forsman, 1999).…”