Home Is Where the Newts Are: Suitability of Artificial Aquatic Sites for the Italian Crested Newt in a Traditional Farming Landscape in Central Italy

In Mediterranean farming landscapes, natural waters are declining, leading to serious consequences for amphibians. In this context, artificial water bodies, used for livestock supply, may represent an ecological surrogate for natural ones. Here, we investigated the habitat suitability of natural and artificial aquatic sites for Triturus carnifex within a farming area where traditional practices are declining. The main goal was to clarify if artificial sites represent keystone habitats contributing to amphibian persistence. Site suitability was assessed by a Habitat Suitability Index (HSI), a body condition index (BCI) and evaluating newt trophic strategy in terms of diet composition and individual specialization (V). HSI was similar in artificial and natural waters, with most study sites falling into the "Good"-"Average" categories. Drinking troughs seem to fulfill the ecological requirements of the species with a habitat suitability that can be improved by a proper management. BCI did not vary between artificial and natural sites, suggesting that newts were well locally adapted, exploited resources with similar energetic cost-efficiency, and experienced similar predation and competition. Diet composition varied between artificial and natural sites because of the opportunistic feeding behavior of T. carnifex, the specialization towards different prey, and site-specific environmental conditions. Individual specialization was significant in artificial and natural sites, confirming the availability of resources in drinking troughs. Indeed, V is more frequent in environments where prey is highly available and profitable to hunt. Our findings suggest that artificial sites with specific habitat suitability sustain specialized individuals with good body conditions. If properly managed, they may support newt vital activities, especially feeding, representing an ecological surrogate for natural sites. In the face of freshwater loss, they represent an opportunity to preserve amphibians in farming landscapes. The recognition of their conservation value is timely, given the spread of intensive farming and the threatened status of many amphibians.