Signaling, Agonistic Behavior, and Life-History Traits of Steppe Agama (<i>Trapelus sanguinolentus</i>) in Prague Zoo

Abstract

Life history traits are influenced by many factors, such as social structure, social displays and aggressive interactions. We investigated signalling and agonistic behavior in relation to body condition and lifespan in Trapelus sanguinolentus, a small, semi-arboreal, oviparous agamid lizard from the Central Asia. We individually examined basic morphological characteristics, number of performed signal displays and relative success in agonistic interactions (via Clutton-Brock index). Life expectancy of males did not differ from life expectancy of females. Overall variability of signals was low and simple push-up display was prevalent signal type for both sexes. Frequency of performed signals differed between sexes with males signalling more. For both sexes number of signals was not associated with life expectancy. Interaction of life expectancy and sex was also not significant. In females — body condition influenced number of performed signals when individuals in better body condition signalled more. Most of agonistic interactions was solved by means of signal displays and did not lead to a direct physical combat. While in males association between CBI and number of signals was not significant, in females higher value of CBI means more performed signals. Conditions of our study (sex ratio 4:1 in favor of females, 20 individuals on 16.5 m2 of terrarium) means that agonistic signals have greater importance for females. The agonistic interactions in females led to direct physical combat more frequently could reflect more competitive intra-sexual environment. Females in better body condition probably used higher signalling activity and better performance in direct combat for access to mates and to places for sunbathing and oviposition.