Difficult coexistence: predation by feral cats threatens the Ibero-Provençal wall lizard
- Feral and community cats put biodiversity at risk in urban and peri-urban ecosystems.
- A study highlights the need to manage cat colonies to protect native fauna.
A recent study published in the Bulletin of the Catalan Society of Herpetology (page 115-137), in which IRBio researchers Antigonio Kaliontzopoulou and Raül Ramos participated, warns that feral and community cat colonies in the Serra de Collserola are having an alarming impact on populations of the Ibero-Provençal wall lizard (Podarcis liolepis). This species, key in Mediterranean ecosystems, is experiencing a significant decrease in abundance, as well as physical and behavioural alterations caused by the predatory pressure of cats.
A direct impact on lizard populations
IRBio of the University of Barcelona researchers, with the support of the Serra de Collserola Natural Park, have found a clear correlation between cat density and the reduction of lizard populations. In areas with a high density of cats, a notable decrease in individuals and an increase in tail injuries have been recorded, an unequivocal sign of predation attempts.
"Mutilated tails are a clear indicator of failed attacks, but even unsuccessful attempts can leave important consequences, such as the loss of energy reserves and vulnerability to other predators," the authors explain. This fact, added to the alteration of the lizards' behaviour patterns, puts their ability to reproduce and maintain stable populations at risk.
Cats as an invasive species
Cats, despite being domestic animals, are considered one of the main invasive species globally, with a significant impact on wild communities. The situation in Collserola is a local example of a global problem: the impact of domestic species on natural and peri-urban ecosystems.
The study was carried out in various locations in the Collserola mountain range, and in adjacent urban areas, analysing areas with different densities of cat colonies. By means of direct observation and monitoring of the lizards, parameters such as catchability, injuries and the general health of the populations were evaluated. The results are conclusive: the lizards are subject to increasing pressure that endangers their survival.
A lesson for urban and peri-urban ecosystems
The authors of the study call for the implementation of effective measures to manage feral and community cat colonies, especially in areas close to sensitive habitats.
The case of Collserola is another example of a global challenge: managing interactions between domestic and native species in natural environments. As urban areas expand, these conflicts are becoming more frequent, and their resolution requires close collaboration between institutions, local communities and the general public.