Evidence for Social Learning in a Family Living Lizard

Abstract

Social learning is widespread among family living species, particularly mammals and birds with relatively high levels of social complexity and overt social interaction. However, the occurrence of social learning has never been documented in lizards with kin-based sociality, which have less obvious social interactions. We tested for social learning in Australian tree skinks (Egernia striolata), a species that commonly lives in family groups in the wild, using a two-step foraging task. Lizards were randomly allocated to either a social learning treatment or a control group and presented first with an instrumental task requiring the displacement of a lid, followed by an association task, consisting of two dishes with different colored lids. Prior to each task, lizards in the social learning treatment observed a trained demonstrator extract a food reward while the control also viewed a conspecific, but in the absence of the foraging task. The social learning treatment and control group solved the instrumental task at similar rates, but in the association task lizards in the social learning treatment made fewer errors and reached our learning criterion sooner. To the best of our knowledge, we present the first evidence for social learning in a lizard with kin-based sociality.

Learning in non‐avian reptiles 40 years on: advances and promising new directions

“…Hatchling three‐lined skinks ( Bassiana duperreyi ) also learned lid removal but only ‘hot’‐incubated lizards acquired this behaviour while hatchlings incubated under ‘cold’ conditions did not (Clark et al ., 2014). Eastern water skinks ( Eulamprus quoyii ) and adult and juvenile tree skinks ( Egernia striolata ) removed lids but neither age class (young or old) or rearing environment (social or solitary) affected performance (Noble et al ., 2014; Riley et al ., 2018; Whiting et al ., 2018). Moreover, spatial learning proficiency did not predict lid‐opening ability in water skinks (Qi et al ., 2018).…”

“…Eight different studies trained lizards to remove lids from wells for a reward; although training was involved, these are also examples of reptiles solving novel problems (Leal & Powell, 2012; Powell, 2012; Clark et al ., 2014; Noble et al ., 2014; Damas‐Moreira et al ., 2018; Qi et al ., 2018; Riley et al ., 2018; Whiting et al ., 2018). Only two studies have tested a reptile using a puzzle box task.…”

“…Although tree skink families remain together for at least one season (Whiting & While, 2017) and juveniles have the opportunity to learn from parents, learning from any adult might have a cost because juveniles experience a high risk of cannibalism from unrelated adult conspecifics (O'Connor & Shine, 2004; While et al ., 2015) and therefore may be less likely to use them as a source of social information. Adult females of this species do learn a two‐choice discrimination readily from other familiar females, showing a decrease in errors and faster learning compared to a control group (Whiting et al ., 2018). Using a familiar parent as a demonstrator for juveniles might thus lead to different results.…”

“…Because some reptiles have evolved early forms of sociality (While et al ., 2015; Whiting & While, 2017) they have also been foundational in understanding how familiarity affects social learning ability (e.g. Whiting et al ., 2018; Munch et al ., 2018 b ).…”

Socioecology of the Australian Tree Skink (Egernia striolata)

“…Targeted study of the nature of Tree Skink parent offspring aggregations, perhaps though the use of focal individual observations or trail cameras which have been enlightening in regard to the extent of parental care present in Cunningham's skinks (Watson et al, 2020), may afford novel insights into direct parental care and communication (see Supplementary Materials for anecdotal observations) within Egernia-group skinks. The potential for communication, and potentially, cultural transmission, is significant in this species, because both juveniles (Riley et al, 2018a) and adults (Whiting et al, 2018) learn socially from one another.…”