Headbobing behavior in the high mountain lizard Phymaturus palluma: effects of sex and context

Headbobbing represents one of the primary sources of communication in Iguanian lizards. Here, we describe and analyze for the first time the form and structure of the headbob display in a species of the Phymaturus genus, and compare it across sexes, social contexts, and with other species of its family. We video-recorded Phymaturus palluma adult lizards, obtained the form and structure of headbobs and evaluated the effect of sex and social context on their performing generalized linear mixed models. We found that in P. palluma, headbob is a complex display composed of several units. Headbob pattern is stereotyped, with less than 35% of variation between individuals, suggesting that it is species-specific. Moreover, units vary among sex and social context, revealing that this display is multicomponent and non-redundant following the multiple-message hypothesis. We also found that the headbob pattern was more complex than in other Liolaemidae lizards, which probably is related to the social systems registered in Phymaturus.

Maternal egg care enhances hatching success and offspring quality in an oviparous skink

Maternal egg-caring behavior can often be observed in oviparous scincid lizards. The expression of such behavior is predictably affected by the trade-off between its resultant costs and benefits for mothers and/or offspring, which has been investigated in only a few scincid species. Here, post-ovipositional Plestiodon chinensis females were treated to care for their egg clutches without interference, under simulated predation pressure, or to be care-deprived. Potential maternal costs and offspring benefits associated with egg-caring behavior were then evaluated by measuring changes in maternal body condition, egg mortality, and hatchling performance. Egg-caring behavior caused post-ovipositional females to participate less in outside-nest activity, eat less food, and show relatively poorer body conditions at egg hatching. By contrast, compared with care-deprived females, egg-caring females gained mass slightly faster, and achieved a similar body condition within a few months of hatching. Eggs that were cared for by their mothers were more likely to hatch and produced larger, faster-running and better-growing hatchlings with higher survival than uncared-for eggs. Simulated exposure to a potential predator had no distinct impact on maternal egg-caring behavior expression and offspring performance. These results indicated that marked benefits of offspring viability but minor maternal energy costs might play a decisive role in the occurrence of maternal egg-caring behavior in P. chinensis.

Maternal care and secretive behaviour of neonates in the highly social lizard Liolaemus leopardinus (Squamata: Liolaemidae) from the central Chilean Andes may relate to size-specific bird predation

Predation prompts the evolution of antipredator traits, molds behaviour, and can lead to the evolution of parental care. We investigated parental care and predator-avoidance behaviour of neonates in the social lizard Liolaemus leopardinus. We used clay models to quantify bird predation pressure on L. leopardinus. Predation was significantly greater on small models and models in open habitat. Late-term pregnant females left their social groups on rock outcrops and gave birth in solitary underneath flat rocks in vegetated microhabitat. Mothers stayed with their litters inside natal chambers for at least 24 h and when they left, sealed the neonates inside. Mothers remained close to their natal chamber and neonates when neonates emerged. Neonates and young yearlings moved significantly less and occupied vegetated microhabitat significantly more than older age classes. We suggest that the maternal behaviour and secretive behaviour of neonates may be related to the heavy avian predation on neonates.

Escape distance and escape latency following simulated rapid bird attacks in an Andean lizard, Phymaturus williamsi

Predatory birds represent the greatest risk for many lizard species. However, little is known about the functional relationship between the escape distance and escape latency of lizards during a rapid bird attack. We hypothesised that escape latency and distance in the Andean lizard species Phymaturus williamsi would increase proportionally, but vary according to the means of escape. Over a three-year period we observed seven types of antipredatory behaviour in 98% P. williamsi lizards on simulated predatory bird attacks. Escape distance and latency were positively correlated. 65% of lizards emerged from their refuge within 2 min of an attack. All of these behaviours were positively correlated with escape latency and distance, although we found the former to be more precise. This study contributes to a better understanding of the general antipredatory behaviour in this species of Andean lizard, and will assist in future decisions concerning its conservation.