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

Abstract

In lizards, males are predicted to sprint faster and run for longer than females by virtue of higher testosterone levels and differences in morphology. Consequently, escape behaviour is also predicted to be associated with sex and locomotor performance, yet these links have rarely been explored. Here, we tested whether escape behaviour is associated with locomotor performance in the toad-headed agama, Phrynocephalus vlangalii, and whether it is sex-dependent. This species is also characterized by elaborate tail displays, which we examined as a potential pursuit-deterrent signal. Tail waves were performed by a very small proportion (2/58, 3 %) of individuals during predatory trials, suggesting that tail signalling functions exclusively in a social context. To understand the relationships between sex, escape behaviour and performance, we first measured escape behaviour (flight initiation distance, flight distance-measured differently compared to previous studies of lizard escape behaviour, and refuge use) in the field before measuring maximal sprint speed and endurance on the same individuals in the laboratory. Flight initiation distance did not differ between the sexes and was unrelated to performance capacity (maximal endurance and sprint speed) but was positively related to body size with larger individuals fleeing earlier. Males fled farther than females, but flight distance was also unrelated to either endurance or sprint speed. Interestingly, faster females were less likely to enter a refuge than slower females, whereas sprint speed and the probability of taking refuge were unrelated for males. Our results suggest that when males and females are not obviously sexually dimorphic, they are more likely to overlap in escape tactics.

Peer Review #1 of "Covariations between personality behaviors and metabolic/performance traits in an Asian agamid lizard (Phrynocephalus vlangalii) (v0.2)"

“…The results showed positive correlation between exploration and endurance capacity, and between bite force and risk-taking willingness. Our current findings, in conjunction with our previous (study showing no correlations between freezing behavior and performance in this species (Qi et al 2014)), support the idea that behaviors in life-history trade-offs are natural history-dependent in P. vlangalii, and provide evidence that behavioral types play functional roles in life history trade-offs to supporting pace-of-life syndrome hypothesis.PeerJ reviewing PDF | (Manuscript to be reviewed 1 Do exploration and risk-taking behaviors covary with metabolism and performance 2 in an Asian agamid lizard (Phrynocephalus vlangalii)? 3 4 5 Abstract 19 Ecological factors related to predation risks and foraging play major roles in determining which 20 behavioral traits may mediate life history trade-offs and, therefore the pace-of-life syndrome 21 structure among behavioral, physiological and life-history traits.…”

“…Second, the subjects were 124 warmed with an infrared heater before measuring endurance and sprint speed in order to ensure 125 the lizards were active and to standardize body temperature (22~35 o C). Detailed protocols for 126 measuring sprint speed and endurance have been described previously (Qi et al 2014). Briefly, 127 lizards were stimulated to run by tapping the base of the tail with a paintbrush ).…”

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

“…The lack of sexual differences in L. schreiberi might be also explained if the more conspicuous males could escape faster than the more cryptic females, as it occurs in many other species (Cullum, 1998;Lailvaux et al, 2005). However, in the agamid lizard Phrynocephalus vlangalii, a species without sexual dimorphism, FID do not differ between the sexes and is unrelated to individual escape performance capacity, although males flee farther than females (Qi et al, 2014). But the reason could be more complex if opposite constraints affect escape decisions of L. schreiberi.…”

Comparability and repeatability of three commonly used methods for measuring endurance capacity

“…The substrate had a light dusting of soil (5 mm) to provide traction on the smooth plastic base of the tub (Bennett, 1980;Huey et al, 1984;Qi, Noble, Wu, & Whiting, 2014), preventing individuals from losing traction or slipping as they ran. The substrate had a light dusting of soil (5 mm) to provide traction on the smooth plastic base of the tub (Bennett, 1980;Huey et al, 1984;Qi, Noble, Wu, & Whiting, 2014), preventing individuals from losing traction or slipping as they ran.…”

“…The stationary track running trials were conducted with an identical setup as the swimming track (a 60 L round plastic tub with a 20 L round plastic bucket fixed in the center). The substrate had a light dusting of soil (5 mm) to provide traction on the smooth plastic base of the tub (Bennett, 1980;Huey et al, 1984;Qi, Noble, Wu, & Whiting, 2014), preventing individuals from losing traction or slipping as they ran. Lizards were considered exhausted when they lowered their body and head to the ground, and no longer ran after having the base of their tail pinched ten times ).…”