A case of cannibalism in Achala copper lizard Pristidactylus achalensis, an endemic lizard to the highest mountain areas in Central Argentina (Squamata: Leiosauridae).

VILADRICH, LEONEL JEREMIAS; NARETTO, SERGIO; TORRES, MARIA DEL MILAGRO

Herpetology Notes

Societas Europaea Herpetologica

Año: 2019 vol. 12 p. 827 - 828

2071-5773

Cannibalism in reptiles seems to occur opportunistically as a by-product of normal predatory behaviour influencing competitive interactions, dynamics and life histories of populations. In some species this behavior has been linked to island populations as a symptom of scarce resources and high lizard densities. Pristidactylus achalensis (Gallardo, 1964) belongs to the Leiosauridae family from austral South America and is endemic to the highest mountains areas in central Argentina, living at an isolated highland ecosystem known as Pampa de Achala. This species is considered omnivorous, feeding on a variety of insects and flowers. However, there are no records of either saurophagy or cannibalism, defined by the process of eating conspecific individuals. We report here a case of cannibalism in Pristidactylus achalensis recorded in the wild and discuss insights on this behaviour. Considering the size of the prey?s tail as reference, we estimated the size of the corresponding individual as approximately 50% of the male predator. In addition, the area is known for its low reptiles? diversity, with P. achalensis being the only lizard species registered. Cannibalism and saurophagy are common behaviours in reptiles, that appears to occur opportunistically as a by-product of normal predatory behavior. We were not able to determine whether the prey was previously dead or if the male predated a conspecific individual, but there are evidences of aggressive encounters within this species. The cannibalism behaviour could be related to aggressive territoriality of males influenced by competitive dynamics. Furthermore, Pampa de Achala region is a mountain ecosystem with harsh climate conditions, and our observation occurred at the end of the species? active season. Cannibalism may give nutritional and energetic benefits when traditional food sources are scarce. Therefore, the necessity of obtaining resources to face hibernation may favour cannibalism events. This unique observation opens new questions about the role of cannibalism in intraspecific interactions in these lizards.