The Price of Tail Loss: Implications of Caudal Autotomy and Regeneration on Male Social Hierarchies in a Territorial Lacertid Lizard

Caudal autotomy is a well-known and widely used defensive strategy among lizards, but its impact on social behaviour, particularly in intramale interactions and dominance hierarchies, has been relatively understudied. In this study, we examined the effects of tail autotomy and subsequent regeneration on the social hierarchy of male Aegean wall lizards (Podarcis erhardii), a territorial species of lacertid lizards. We found that tail loss significantly reduced the ability of adult males to dominate same-sized conspecifics, hinting at a possible difficulty in securing high-quality territories, potentially reducing access to mating opportunities and increasing mortality risks. Both autotomised dominant and intact subordinate males in our interactions adjusted their behaviour following autotomy, with dominant males reducing their aggression and subordinate ones increasing theirs. Surprisingly, tail regeneration did not restore social status or aggression levels to pre-autotomy conditions, suggesting that social costs of tail loss could extend beyond the associated decrease in body size and may persist even after the tail has fully regenerated. These results indicate that caudal autotomy could have lasting consequences on male social interactions and potentially significant implications for reproductive success and survival. Our study highlights the complex role of tail condition in the social dynamics of territorial lizards and calls for further research on the long-term impacts of autotomy on fitness and social structures.