Explore the vast range of titles available.

The ecological theory of island biogeography suggests that mainland populations should be more genetically divergent from those on large and distant islands rather than from those on small and close islets. Some island populations do not evolve in a linear way, but the process of divergence occurs more rapidly because they undergo a series of phenotypic changes, jointly known as the Island Syndrome. A special case is Reversed Island Syndrome (RIS), in which populations show drastic phenotypic changes both in body shape, skin colouration, age of sexual maturity, aggressiveness, and food intake rates. The populations showing the RIS were observed on islets nearby mainland and recently raised, and for this they are useful models to study the occurrence of rapid evolutionary change. We investigated the timing and mode of evolution of lizard populations adapted through selection on small islets. For our analyses, we used an ad hoc model system of three populations: wild-type lizards from the mainland and insular lizards from a big island (Capri, Italy), both Podarcis siculus siculus not affected by the syndrome, and a lizard population from islet (Scopolo) undergoing the RIS (called P. s. coerulea because of their melanism). The split time of the big (Capri) and small (Scopolo) islands was determined using geological events, like sea-level rises. To infer molecular evolution, we compared five complete mitochondrial genomes for each population to reconstruct the phylogeography and estimate the divergence time between island and mainland lizards. We found a lower mitochondrial mutation rate in Scopolo lizards despite the phenotypic changes achieved in approximately 8,000 years. Furthermore, transcriptome analyses showed significant differential gene expression between islet and mainland lizard populations, suggesting the key role of plasticity in these unpredictable environments.

Background New epidemiological data on bacterial and parasitic infections in 24 Italian wall lizards, namely Podarcis sicula (mainland population) and P. sicula klemmerii (insular population) in southern Italy were provided. To achieve this goal, samples were collected from individuals belonging to the two populations and analysed by microbiological and parasitological methods. Results A wide range of bacteria (e.g. Pantoea spp., Citrobacter spp., Morganella spp., Pseudomonas , Enterobacter spp., Staphylococcus spp. and Escherichia coli ) and parasites (e.g. Ophionyssus natricis , coccidia, Dicrocoelidae) were detected in both P. sicula and P. sicula klemmerii individuals. Insular population presented similar bacterial and parasitic diversity to its mainland counterpart. Ampicillin was the antimicrobial with the highest resistance rate. Conclusion This study highlighted various bacteria and parasites, some of them potentially zoonotic. Further studies are needed to better understand the epidemiology and transmission routes of these pathogens along with their impact on the welfare and behaviour of Italian wall lizards.

Biological invasions are a contemporary global threat because invasive species can have substantial negative economic and ecological impacts. Invasive species can outcompete native species through two main mechanisms: interference competition (direct, negative interactions like aggression) and/or exploitative competition (indirect, negative interactions resulting from species using the same, limited resources like food). The invasive Italian wall lizard (Podarcis siculus) was introduced into Lisbon, Portugal, 20 years ago, and is believed to be locally displacing the native green Iberian wall lizard (Podarcis virescens). We experimentally tested for competition between these two lizard species by establishing heterospecific (one pair of each species) and conspecific (two pairs of the same species; control) treatments in enclosures containing a high- and a low-quality refuge. Lizards were fed from food dishes every other day. We tested if species showed interference (aggressive behaviour, stealing food and shelter exclusion) or exploitative competition (tolerance between species but differences in food consumption efficiency). We found evidence for exploitative competition: the invasive species arrived first at food stations, consumed more food and gained more weight than the native species. We suggest that exploitative competition may, in part, explain the observed displacement of P. virescens from contact areas with the invasive P. siculus. Deciphering the competitive mechanisms between invasive and native species is vital for understanding the invasion process.

The Aeolian wall lizard Podarcis raffonei is an island endemic that survives only on three tiny islets, and on the Capo Grosso peninsula of the Vulcano island, thus is among the European vertebrates with the smallest range and one of the most threatened by extinction. This species is declining due to competition and hybridization with the non-native lizard Podarcis siculus , but a regular monitoring program is lacking. Here we assessed the size and status of the Capo Grosso population of P . raffonei on Vulcano. In September 2015 we captured 30 individuals showing the typical brown phenotype of P . raffonei , while one single male showed a green phenotype, apparently intermediate between P . raffonei and the non-native Podarcis siculus . In May 2017, only 47% of 131 individuals showed the typical brown phenotype ( P . raffonei -like) and 53% showed the green phenotype ( P . siculus -like). Based on N -mixture models and removal sampling the estimated size of the Capo Grosso population was of 800–1300 individuals in 2017, being similar to 2015; available data suggest that the total range of the species could be as small as 2 ha. The frequency of individuals with the typical P . raffonei phenotype dramatically dropped between two samplings with a parallel increase of individuals displaying the green phenotype. Observation on outdoor captive-bred individuals demonstrates plasticity for colouration in P . raffonei individuals from Capo Grosso, with several individuals showing the typical brown pattern in September 2017 and a green pattern in March 2021. Non-exclusive hypotheses, including hybridization with P . siculus and plasticity in colour pattern of P . raffonei , are discussed to explain the phenotypic shifts of the P . raffonei population of Capo Grosso. While genomic evidence is required to reach conclusions and investigate eventual hybridization, it is urgent to undertake a programme for the monitoring and management of this lizard.

Background Behavioral adaptations are considered an important factor of population success in colonizing novel environments. Individuals can be selected for specific behavioral traits during transport, introduction and especially establishment phase of the invasion process. Aside from population level average of behavioral traits, both among- and within individual variability can contribute to achieving behavioral optima for efficiently acquiring resources in new habitats. Here, we study activity/exploration behavioral traits and boldness in a novel insular population of Italian wall lizard ( Podarcis siculus ) with a known colonizing history and propagule pressure. We apply Bayesian mixed-effects models and variance partitioning to compare the activity/exploration behavioral traits and boldness between ancestral population from Pod Kopište island and novel population from Pod Mrčaru island. Results We found no difference in average levels of activity/exploration behavioral traits (distance moved and angular velocity) or boldness between populations or sexes. Among-individual variance in both behaviors was preserved in novel population, despite small propagule size of ten individuals. Females from ancestral Pod Kopište had substantially lower within-individual variability of distance moved than males. However, females within-individual variability for this trait increased in the novel Pod Mrčaru population, while males remained the same. Females on Pod Mrčaru population also exhibited strong increase in within-individual variability in angular velocity, even surpassing the values denoted for males in that population. In contrast, within-individual variance in boldness did not differ across population by sex groups. Conclusions Our results show that among-individual behavioral variation can be preserved even in populations founded by small propagule. Our study also demonstrates sexual dimorphism in the within-individual variability of activity/exploration behavioral traits, both within the populations and in the direction and intensity of change in a new environment. Collectively, this study highlights the importance of studying behavioral flexibility in addition to average population or individual behavioral traits and emphasizes the role of females’ activity/exploration in adaptation to new environments.

Background Leishmania tarentolae is a protozoan isolated from geckoes ( Tarentola annularis , Tarentola mauritanica ), which is considered non-pathogenic and is transmitted by herpetophilic Sergentomyia spp. sand flies. This species occurs in sympatry with Leishmania infantum in areas where canine leishmaniasis is endemic. In the present study, we investigated the circulation of L. tarentolae and L. infantum in sand flies, dogs and lizards in a dog shelter in southern Italy, where canine leishmaniasis by L. infantum is endemic. Methods Sheltered dogs ( n  = 100) negative for Leishmania spp. (March 2020) were screened by immunofluorescence antibody test (IFAT) using promastigotes of both species at two time points (June 2020 and March 2021). Whole blood from dogs, tissues of Podarcis siculus lizards ( n  = 28) and sand flies ( n  = 2306) were also sampled and tested by a duplex real-time PCR (dqPCR). Host blood meal was assessed in sand flies by PCR. Results Overall, 16 dogs became positive for L. infantum and/or L. tarentolae by IFAT at one or both sampling periods. One canine blood sample was positive for L. infantum , whilst two for L. tarentolae by dqPCR. At the cytology of lizard blood, Leishmania spp. amastigote-like forms were detected in erythrocytes. Twenty-two tissue samples, mostly lung (21.4%), scored molecularly positive for L. tarentolae , corresponding to 10 lizards (i.e., 35.7%). Of the female Sergentomyia minuta sampled ( n  = 1252), 158 scored positive for L. tarentolae , four for L. infantum , and one co-infected. Two Phlebotomus perniciosus (out of 29 females) were positive for L. tarentolae . Engorged S. minuta ( n  = 10) fed on humans, and one P. perniciosus , positive for L. tarentolae , on lagomorphs. Conclusions Dogs and lacertid lizards ( Podarcis siculus ) were herein found for the first time infected by L. tarentolae . The detection of both L. tarentolae and L. infantum in S. minuta and P. perniciosus suggests their sympatric circulation, with a potential overlap in vertebrate hosts. The interactions between L. tarentolae and L. infantum should be further investigated in both vectors and vertebrate hosts to understand the potential implications for the diagnosis and control of canine leishmaniasis in endemic areas. Graphical abstract

Background Borrelia burgdorferi ( sensu lato ) is a complex containing pathogenic bacteria of which some species, such as Borrelia lusitaniae , use birds, small mammals and reptiles as reservoirs. In Italy, the bacteria have been detected in reptilian and avian reservoirs in the northern and central regions. Results Here, 211 reptiles from three orders [Squamata (Sauria with seven species in five families and Ophidia with 11 species in three families), Crocodylia (one family and two species), and Testudines (two families and two species)] were examined for ectoparasites and molecular detection of B. burgdorferi ( s.l. ) in three different sites of southern Italy, an area for which no information was previously available on the occurrence of borreliosis in animals and humans. Borrelia lusitaniae was molecularly detected in larvae and nymphs (11.6%) of Ixodes ricinus infesting lizards (i.e. Podarcis muralis , Podarcis siculus and Lacerta bilineata ) and in 12.3% blood samples of P. siculus . Finally, B. lusitaniae and Borrelia garinii were detected in 5.1% (32/630) of questing I. ricinus . Conclusions These results show the circulation of B. lusitaniae in southern Italy and suggest that P. siculus could play a role as a reservoir, representing a potential medical threat to humans living in or visiting these localities.

Aposematism is a distinctive or warning signal that provides the animal with protection against a potential predator. Aposematic colouration is easier for a predator to remember and to avoid a dangerous and/or unpalatable prey in the future. We investigated whether distinctive colouration has an aposematic function in terrestrial isopods. The common rough woodlice ( Porcellio scaber ) were used as a model species of terrestrial isopods and the Italian wall lizard ( Podarcis siculus ) as a predatory species. To imitate the distinctive colouration on isopods we marked their dorsal plates with yellow dots. The control group of the woodlice were marked with grey spots. Differences in behaviour (observation, manipulation and consummation) and the lizards’ behaviour changes towards aposematically and cryptically coloured prey were analysed. Differences were found in prey observation both between sexes and between prey colours.

Abstract Urbanization occurs at a global scale, imposing dramatic and abrupt environmental changes that lead to biodiversity loss. Yet, some animal species can handle these changes, and thrive in such artificial environments. One possible explanation is that urban individuals are equipped with better cognitive abilities, but most studies have focused on birds and mammals and yielded varied results. Reptiles have received much less attention, despite some lizard species being common city dwellers. The Italian wall lizard, Podarcis siculus, and the common wall lizard, Podarcis muralis, are two successful lizards in anthropogenic habitats that thrive in urban locations. To test for differences in a cognitive skill between urban and semi-natural environments, we investigated inhibitory control through a detour task in syntopic populations of the two species, across 249 lizards that were tested in partially artificial field settings. Sophisticated inhibitory control is considered essential for higher degrees of cognitive flexibility and other higher-level cognitive abilities. In this task, we confronted lizards with a transparent barrier, separating them from a desired shelter area that they could only reach by controlling their impulse to go straight and instead detour the barrier. We found no differences between lizards in urban and semi-natural environments, nor between species, but females overall performed better than males. Moreover, 48% of the lizards in our study did not perform a correct trial in any of the 5 trials, hinting at the difficulty of the task for these species. This study is among the first to address lizard cognition, through their inhibitory control, as a potential explanation for success in cities and highlights one should be careful with assuming that urban animals generally have enhanced cognitive performance, as it might be taxa, task, or condition dependent.

Different environmental contaminants disturb the thyroid system at many levels. AlkylPhenols (APs), by-products of microbial degradation of AlkylPhenol Polyethoxylates (APEOs), constitute an important class of Endocrine Disrupting Chemicals (EDCs), the two most often used environmental APs being 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP). The purpose of the present study was to investigate the effects on the thyroid gland of the bioindicator Podarcis siculus of OP alone and in combination with NP. We used radioimmunoassay to determine their effects on plasma 3,3′,5-triiodo-L-thyronine (T3), 3,3′,5,5′-L-thyroxine (T4), thyroid-stimulating hormone (TSH), and thyrotropin-releasing hormone (TRH) levels in adult male lizards. We also investigated the impacts of AP treatments on hepatic 5′ORD (type II) deiodinase and hepatic content of T3 and T4. After OP and OP + NP administration, TRH levels increased, whereas TSH, T3, and T4 levels decreased. Lizards treated with OP and OP + NP had a higher concentration of T3 in the liver and 5′ORD (type II) activity, whereas T4 concentrations were lower than that observed in the control group. Moreover, histological examination showed that the volume of the thyroid follicles became smaller in treated lizards suggesting that that thyroid follicular epithelial cells were not functionally active following treatment. This data collectively suggest a severe interference with hypothalamus–pituitary–thyroid axis and a systemic imbalance of thyroid hormones.Graphic Abstract