Sex‐Based Differences and Similarities in Locomotor Performance, Thermal Preferences, and Escape Behaviour in the LizardPlatysaurus intermedius wilhelmi

Abstract

Differences between sexes in physiological performance have received little attention in animals. We tested for sex differences in maximum sprint speed and maximal exertion over a range of temperatures in a population of Platysaurus intermedius wilhelmi lizards. We also examined sex-based differences in selected temperature range, mean field body temperatures (T(b)), and thermal activity limits. Finally, we conducted field studies to quantify male and female responses to a potential predator, which may be affected by their respective performance capabilities. Males were faster than females at all temperatures, and body size had no significant effect on sprint speeds. Males and females also selected similar T(b)'s when placed in a thermal gradient, but in the field, male lizards' T(b)'s were different from those of the females. However, predicted sprint speeds for males and females at their field T(b)'s are similar. No significant differences were found between males and females with regard to maximal exertion. When approached in the field, adult male lizards took refuge significantly earlier than did adult females and also fled over shorter distances, suggesting that females rely on crypsis as an escape strategy.

Sex- and performance-based escape behaviour in an Asian agamid lizard, Phrynocephalus vlangalii

“…Therefore, selection on performance traits is frequently predicted to be sex-dependent (Lailvaux 2007;Irschick et al 2008;Van Damme et al 2008;Noble et al 2014), and this may in turn influence escape behaviour in different ways for males and females. Typically, males are predicted to delay fleeing and run shorter distances in escaping because males are usually reported to run faster and longer than females by virtue of differences in morphology and higher testosterone levels (Klukowski et al 1998;Lailvaux et al 2003;Noble et al 2014). Conversely, females may adjust their escape behaviour and rely more on crypsis if their performance capacity is reduced (Vanhooydonck et al 2007;Goodman et al 2008).…”

“…We currently have few tests of sex-based differences in escape behaviour or performance capacity in lizards (Lailvaux et al 2003;Martin et al 2009;Noble et al 2014). For example, Lailvaux et al (2003) found sexual differences in sprint speed but no differences in endurance in the lizard Platysaurus intermedius wilhelmi, and males were found to take refuge earlier and flee farther than females.…”

“…Nevertheless, the act of fleeing will alert the predator; therefore, the prey will have to trade-off the benefits of remaining stationary against the cost of being detected (Broom and Ruxton 2005). No matter the model, escape decisions are critical to an individual's fitness (Cooper and Frederick 2007) and these decisions may depend on an individual's intrinsic capacity to escape predation (Clobert et al 2000;Kullberg et al 2002;Lailvaux et al 2003).…”

“…For example, conspicuous individuals are predicted to flee earlier than cryptic ones if escape costs are low (Martin et al 2009). Additional measures of risk assessment during escape include flight distance and latency to enter a refuge (Martin and Lopez 2000;Lailvaux et al 2003;Martin and Lopez 2010). Locomotor performance capacity (sprint speed and endurance) is potentially a key driver of escape behaviour because of its obvious influence on evading capture by a predator.…”

Escape strategy of Schreiber’s green lizards (Lacerta schreiberi) is determined by environment but not season or sex

“…Also, in several cases, there are differences between the escape tactics of males and females. For example, in lizards with sexually dichromatic coloration, males, with more conspicuous colorations, have longer FIDs than females in some species (Lailvaux et al, 2003;Martín & López, 1999a) but not in others (Smith, 1996(Smith, , 1997Cooper & Wilson, 2007;Whiting, 2002). Male green lizards, Lacerta viridis, have longer FIDs than females before and after the mating season, but during the mating season the difference dissipates (Majláth & Majláthová, 2009).…”