Social and spatial patterns of two Afromontane crag lizards (Pseudocordylus spp.) in the Maloti‐Drakensberg Mountains, South Africa

Abstract

Understanding the evolution of vertebrate sociality requires comparative data on social associations across the vertebrate phylogeny. In the case of group-living lizards (i.e. species that live in stable social aggregations often associated with a shared resource), most work has focused on the Egerniinae in Australia, resulting in a taxonomic and geographic skew to our understanding of reptile sociality. The African cordylid lizards (Cordylidae) are also a promising system to study the evolution of sociality because grouping behaviour varies across the clade. Here, we studied the conspecific grouping behaviour of two crag lizards, Pseudocordylus langi and P. melanotus subviridis that occur at high elevations in the Maloti-Drakensberg Mountains of South Africa. To better understand their social organisation and mating system, we also present data on their spatial distribution, sexual dimorphism, and bite force. Both Pseudocordylus spp. were sexually dimorphic in morphology (males had larger heads than females of similar body size), colouration (males were more colourful) and female P. langi had a weaker bite force than males. Both P. langi and P. m. subviridis were associated with rocky habitat on the mountainside (e.g. cliffs, rock buttresses, and rock outcrops) and both were spaced apart and rarely in groups (79% of P. langi and 90% of P. m. subviridis were observed alone). Based on our findings, we hypothesise that both Pseudocordylus spp. have a territorial social structure and a polygynous mating system. This novel natural history information about crag lizards supports the assertion that Cordylidae is another model system for examining the evolution of sociality.

Sperm Storage in a Family-Living Lizard, the Tree Skink (Egernia striolata)

“…A c c e p t e d M a n u s c r i p t 7 (Hosken, Garner, & Ward, 2001;Martin & Hosken, 2007), which is reflected in their lack of dramatic sexual dimorphism (Riley et al 2021).…”

Partitioned parturition: Birthing asynchrony in cordylid lizards

“…Here, we examine if birthing asynchrony is present in a geographically distinct, but ecologically and socially similar clade of reptiles to the egerniine skinks, the cordylid lizards (Cordylidae) of sub‐Saharan Africa (Riley et al., 2021). The family Cordylidae contains 10 genera (Stanley et al., 2011), and like many of the egerniine skinks, cordylid lizards are crevice‐ or burrow‐dwelling, ambush foraging, viviparous lizards with small litter sizes (typically 1–4 offspring, but up to 7 for certain species; Reissig, 2014) that display a varying degree of sociality, ranging from solitary to large social groups (Mouton, 2011; Whiting & While, 2017).…”

Sexual Dimorphism in Namibian Endemic Herero Nama Lizards ( Namazonurus pustulatus)

“…In general, cordylid research has largely focused on morphology to better understand cordylid life history and evolution (Costandius and Mouton 2006). As a result, sexual size dimorphism data are available for 13 of the approximately 80 cordylid species (Fell 2005; summary of 10 in Costandius and Mouton 2006;Broeckhoven and Mouton 2014;Riley et al 2021) with much variation within and among species. Females are larger in six species (Chamaesaura anguina, Cordylus macropholis, Karusasaurus polyzonus, Hemicordylus capensis, Hemicordylus nebulosus, and Smaug giganteus), males are larger in six species (Cordylus cordylus, Cordylus niger, Namazonurus peersi, Ouroborus cataphractus, Pseudocordylus langi, and Pseudocordylus melanotus subviridis), and in one species there is no difference between the sexes (Pseudocordylus microlepidotus).…”

“…Furthermore, tail length relative to snout-vent length (SVL) is greater in adult males than that in adult females for some species but not others (Costandius and Mouton 2006). In general, male cordylids are larger in overall body size and head dimensions (Fell 2005;Costandius and Mouton 2006;Broeckhoven and Mouton 2014;Riley et al 2021). However, allometric head growth relative to SVL varies, where heads are larger in adult males than in adult females, larger or equivalent in juveniles than in adult males, and/or larger in juveniles than in adult females (Costandius and Mouton 2006).…”