Descriptive studies of behavioral repertoires are often conducted on captive animals. While captivity makes observation straightforward, it can inadvertently alter natural behavior through stress or the development of stereotypies. Studies in the wild, by contrast, provide a far more authentic reflection of a species' natural behavior, despite the significant challenges and observational limitations they impose.

In the latest issue of Acta Herpetologica, a new study successfully overcomes these fieldwork hurdles to deliver the first complete behavioral repertoire for the Madeiran wall lizard (Teira dugesii). Researchers captured over 70 hours of video recordings under natural field conditions across four sampling periods between 2022 and 2024. Using these recordings alongside supplementary field notes, behaviors were classified into five core categories: maintenance, mobility, feeding, aggression/defense, and reproduction.

The vast majority of the observations—approximately 86.5%—involved maintenance behaviors, reinforcing their central role in the daily life of T. dugesii. This dominant focus is shared by many other lacertid lizards, primarily because maintenance activities are crucial for thermoregulation. Furthermore, because these behaviors require minimal energy investment, their predominance allows the lizards to thrive without straining their daily energetic budget.

Mobility behaviors accounted for just 7% of the observed repertoire, suggesting that T. dugesii carefully balances environmental exploration with energy conservation. Accordingly, most observed movements occurred at a slow pace (walking). Fast movements, such as running and jumping, were rare and strictly tied to specific ecological triggers like disturbance, social interactions, or hunting. Feeding behaviors comprised 2% of the total repertoire, with active predation and nectar-licking emerging as the most frequent activities.

Interestingly, behaviors related to aggression or defense were also uncommon, making up only 4% of the observations. Like many island-dwelling species, T. dugesii experiences reduced predation pressure, resulting in less elusive behavior compared to its mainland relatives. Aggressive interactions were rare and strictly limited to the summer months. This lack of overt conflict likely stems from the species' high population density; similar to other lacertids under crowded conditions, these lizards appear to rely more on subtle visual displays than physical combat, successfully preserving energy and avoiding injury.

Finally, reproductive behaviors accounted for a minimal 0.5% of the total repertoire. Mating activities were observed specifically in May and August, though hatchlings were seen emerging throughout the entire year.

Click here to read the full paper, to explore the complete behavioral blueprint of this fascinating island reptile.

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