PODARCIS
Unraveling biological invasions: cosequences of a rapidly spreading snake invasion for a Mediterranean endemic lizard
The main objective of the project is to determine the ecological and evolutionary consequences of biological invasions. Specifically, it is examined whether the arrival of a new terrestrial predator on the island of Ibiza is exerting new natural selection pressure on the native lizard populations of the Pitiusas, which have evolved without the presence of these predators.
Biological invasions are a major cause of island biodiversity loss in the Anthropocene. Extinction of island endemics is commonly associated with their ‘island tameness’, a lack of behavioral responses to effectively deal with novel predators. Despite studying this process should be a global conservation priority to preserve island biota, how animal behavior affects ecological and evolutionary dynamics of native populations as a response to novel predators remains poorly understood. This is mostly due to the difficulty of finding suitable study systems to unravel the early stages of behavioral adaptation to predator invasion.
The endemic Ibiza wall lizard evolved in the absence of snakes. With the recent arrival and spread of Iberian horseshoe whip snakes, lizard densities have plummeted in invaded areas, thereby threatening population persistence and the ecosystem services they provide as pollinators and seed dispersers.
Taking advantage of this unique study system, we will 1) conduct a large-scale experiment to test if natural selection targets individual variation in antipredator behavior; 2) investigate if changes in the foraging behavior of wall lizards have cascading consequences for ecosystem functioning; 3) engage local high-school students in a citizen science project. Our results will not only contribute to preserve a delicate Mediterranean ecosystem but they will also provide essential integrative insight of the impact of predator-driven biodiversity loss.