Aggressive interactions between a sand lizard Lacerta agilis and a common wall lizard Podarcis muralis in England

I Germany, the native sand lizard (Lacerta agilis) and the invasive alien wall lizard (Podarcis muralis) have been observed to have strongly overlapping local distributions with a very high rate of overlap in substrate selection, especially between the males of the two species (Heym et al., 2013). However, interspecific interactions were apparently rare (mainly basking at a distance). Nevertheless, in England the native L. agilis has been observed to respond to the scent of P. muralis with direct aggression while in another native lizard species, Zootoca vivipara, the response was only avoidance (Williams et al., 2020). In Poole, Dorset (England) in one of the few areas where both L. agilis and the alien P. muralis can be observed in close proximity, I made further observations that confirm the aggressive responses between the two species. At around 13:00 h on 29th April 2019, I observed an adult, male wall lizard. It was basking on a low, sandy bank backed by cliffs adjacent to a busy footpath close to the sea, on a sandy area between the vegetation, facing slightly up the gradient and away from the footpath. An adult, male sand lizard in breeding condition then approached the area from higher up the slope and slowly crawled alongside the wall lizard, close enough for the back legs of the two lizards to be in contact, the sand lizard facing down the slope towards the footpath (Fig. 1A). Almost at once the wall lizard began to move away, taking a couple of paces up the slope before stopping and turning its head to look in the direction of the new arrival. At this time the wall lizard was standing on the tail of the sand lizard. The sand lizard then turned towards the departing lizard which then moved off again a few centimetres up the slope (Fig. 1B). The sand lizard then followed after the wall lizard which was moving away slowly. The larger sand lizard then grasped the tail of the other lizard in its jaws, about 3 cm from the tail tip. The wall lizard continued on for another couple of paces and appeared to be dragging the sand lizard along behind it before turning back down the slope to face towards its attacker (Figs. 2A & B). The Herpetological Bulletin 155, 2021: 28-29