The role of size and aggression in intrasexual male competition in a social lizard species, Egernia whitii

Sex, Age, and Population Density Affect Aggressive Behaviors in Island Lizards Promoting Cannibalism

“…The high percentages of aggressive behavior between males reflect their intrasexual competition for territory, food, and mates (Yasui ; Lailvaux & Irschick ; McEvoy et al. ). Intrasexual competition in male lizards often leads to fighting, which may inflict injury because the larger heads of males exert high bite force (Cooper & Vitt ; Husak et al.…”

“…As expected, the frequency of aggressive responses between males from both populations was much higher than that between females. The high percentages of aggressive behavior between males reflect their intrasexual competition for territory, food, and mates (Yasui 1998;Lailvaux & Irschick 2007;McEvoy et al 2012). Intrasexual competition in male lizards often leads to fighting, which may inflict injury because the larger heads of males exert high bite force (Cooper & Vitt 1987;Husak et al 2009;Herrel et al 2010).…”

Aggressiveness as a component of fighting ability in pigs using a game-theoretical framework

“…However, the majority of studies in this area have focused on investigating links along the boldeshy personality spectrum, and proactiveereactive behavioural syndrome, and contest behaviour (Briffa et al, 2015: Table 1, out of 16 cited studies only one directly investigated links between aggression and RHP). The limited research that has been conducted on aggressiveness in relation to contest behaviour has produced conflicting results (McEvoy et al, 2013;Wilson et al, 2013; see above). Our study adds another layer of complexity by the findings of an indirect effect of aggressiveness on contest behaviour (bite initiation).…”

“…This may be a logical response to the level of challenge. When both opponents retaliate equally to each other's attacks, the intensity of the contest may rapidly increase and contestants may sooner move towards escalated aggression (Maynard Smith & Price, 1973). If one opponent avoids confrontation but does not signal a clear retreat the contest may be prolonged until eventually one gives up, either with or without escalated aggression prior to the withdrawal.…”

A different kind of ecological modelling: the use of clay model organisms to explore predator–prey interactions in vertebrates

“…Becasue this topic does not pertain to predation, we shall provide only a brief review of the topic here. Realistic clay models have been used to elicit responses in captive Egernia whitii skinks (Sinn, While & Wapstra, ; While, Sinn & Wapstra, ; While et al ., ; McEvoy et al ., ) and it is encouraging to note that even conspecifics outside of a predator–prey situation are sufficiently convinced by clay models that they will react to them as to real animal. In the field, McMillan & Irschick () found that clay models of green anoles A. carolinensis were bitten by male green anoles (identified by distinctive bite patterns) and that there was both a habitat and seasonal influence, with more models bitten by anoles in urban areas and more bites occurring during spring and autumn, suggesting peaks in competitive selection pressures.…”