Search Results (5)

Amphibians face a multitude of threats and therefore make a prime example of the current biodiversity crisis. Multiple amphibian stressors in anthropogenic landscapes include infectious diseases and agrochemicals. Synergic effects between these stressors may increase the negative impact of infections on amphibian health. In a 56-day trial, we assessed the impact of co-exposure to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and the pathogenic fungus Batrachochytrium salamandrivorans (Bsal) on infection parameters (infection intensity and disease severity) and health (body condition and telomere length) in Italian crested newts (Triturus carnifex). Twenty days post-inoculation with Bsal, newts were either exposed to 2,4-D for 12 days or not exposed (control). Most newts developed high infection loads that steadily increased towards the end of the trial. While body condition was negatively correlated with pathogen burden, only one out of 23 animals died. Telomere length remained unaffected by the pesticide and the pathogen. The 2,4-D treatment did not exacerbate Bsal infection. Most newts survived almost two months with significant pathogen loads; thus, even in a pesticide-infested environment, T. carnifex could be an important long-term Bsal reservoir for co-occurring species on the Italian peninsula, a urodele diversity hotspot. Full article

The Calabrian Peninsula (Southern Italy) has acted as a glacial refugium and is now considered a hotspot for the genetic diversity of several species. Even if it hosts the highest diversity of many Italian endemic amphibian species, the distribution of some of these needs an update to address conservation measures. We took advantage of a vast dataset for three Italian species (Bombina pachypus, Salamandrina terdigitata, Triturus carnifex), two of which are endemic, deriving from a 40-year field surveys dataset (1982–2022), to update their distribution and basic ecological requirements. We evaluated changes in their distribution, projecting them on a broader spatial scale through a kernel density estimation, inferring statistically-significant hotspots using Corine Land Cover patches, and assessing the protected areas’ coverage. We confirmed that Pollino, Catena Costiera, Sila and Aspromonte massifs are the main statistically-significant hotspots. Kernel densities showed a diversified pattern of gains/losses, sometimes overlapping, depending on the species. The whole outcomes obtained allow us to pinpoint specific areas where effective conservation measures need to be applied. Ousr findings reveal that local-scale monitoring and management should be planned, especially within the existing nationally-designated protected areas, which have been shown to protect far less with respect to the Natura 2000 sites. Full article

Natural aquatic sites are disappearing worldwide, especially in the Mediterranean region where amphibians are frequently forced to move for reproduction to artificial sites designed for irrigation and cattle watering (i.e., wells, tanks and drinking troughs). In artificial aquatic sites, where resources (space and food) are usually limited, trophic niche information can be particularly useful to infer the suitability of habitats for amphibian conservation especially when more than one species co-occurs. In this paper, we focused on three newt species: The Italian newt (Lissotriton italicus), the Italian smooth newt (Lissotriton vulgaris meridionalis) and the Italian crested newt (Triturus carnifex) inhabiting man-made wells widespread in an area in Central Italy characterized by few available natural aquatic sites. Specifically, we analyzed the trophic spectrum of the species, their interactions and overlap, and discussed the potential role of wells in amphibian conservation. Overall, 550 newt individuals occurring in 16 distinct wells were sampled. The study species consumed similar resources, mainly of aquatic origin, with Diptera larvae and Cladocera representing the most important preys. The high degree of diet overlap observed may be due to site oligotrophy and high availability of small-sized prey, and it does not necessarily lead to competition. Newts had similar narrow niche width values and a generalist feeding pattern with high diversity among individuals. Lissotriton italicus and T. carnifex showed wider niche width in isolation than in syntopy condition, probably as a result of interspecific competition and/or intraguild predation. We showed that artificial aquatic sites are important for newt ecology and conservation since they allow up to three species to cohabit, thus representing a good surrogate of natural habitats. The study wells apparently provided suitable trophic conditions for newts in terms of prey availability and catchability. To date, just a few studies have contributed to a greater understanding of newts’ diet in artificial aquatic sites and this gap of knowledge has to be filled to clarify their role in amphibian ecology and conservation. Full article

Mountain karst ponds are sensitive environments, hosting complex trophic networks where amphibians play a major role, often as top predators. The diet of the Italian crested newt (Triturus carnifex) is still poorly known for populations occupying mountain karst ponds. These are traditionally used as livestock’s watering points, leading to water pollution due to excreta and wading behavior. The aim of this paper is to understand the relationship between T. carnifex diet composition, assessed through the stomach flushing technique, and physical and chemical characteristics in mountain ponds, focusing on parameters altered by livestock pressure, such as ammonium concentration and dissolved oxygen. The high diversity of prey items found within the newts’ gut contents confirms the generalist diet even in mountain ponds. The number of prey taxa, their relative abundance and Shannon–Wiener diversity index show variations among the sampled sites, related to livestock organic pollution. Moreover, we report the very first European records of microplastic items in amphibians’ stomach content, which also represent the first evidence for Caudata worldwide. Our findings suggest that livestock pressure directly influences T. carnifex diet and highlight that the emerging issue of plastics is a threat even in remote high-altitude environments. Full article

We have studied the population genetic structure of slightly admixed populations of crested newts (Triturus cristatus and T. carnifex) in a continuously fragmented landscape, located in northern Salzburg (Austria) and neighbouring Bavaria (Germany). Crested newts are listed as Critically Endangered in the provincial Red List of Salzburg and strictly protected by the EU Habitats Directive. We used seven polymorphic microsatellite loci to evaluate genetic diversity and processes that may determine the genetic architecture of populations. Genetic diversity was moderate, pairwise F_ST-values were comparatively high showing significant genetic differentiation and limited gene flow. Isolation by distance was significant for the whole data set, but not significant when calculated for T. cristatus- and T. carnifex-like populations separately. Bayesian analyses of population structure, using three different programs showed similar results. Spatial statistics reveal that the geographical isolation of populations is very high. Full article