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The variations in the niches of species within a clade depend on the complex interplay among geography, climatic history, and species-specific factors. For the first time, we investigated the evolutionary patterns in the climate and habitat niches of 50 species in the order Squamata and a nested subclade (family Lacertidae) in southwest Europe. The habitats of species were characterized at three spatial levels: 1 km2 (macrohabitat), 2830 m2 (mesohabitat), and 100 m2 (microhabitat). We compared three evolutionary models Brownian motion, Ornstein-Uhlenbeck, and Early Burst and fitted Pagel models (lambda, kappa, and delta) to the niche variations to assess the strength of the phylogenetic signal, tempo, and mode of evolution. We expected: (i) that the habitat niche would be more labile than the climate niche; and (ii) variability in the rate of niche evolution as a response to recent climate cycles. The Ornstein-Uhlenbeck model provided a better fit for the different dimensions of the niche, implying evolutionary attraction towards the niche optimum. In the climatic niches for both groups of taxa, a model with an accelerated rate of evolution was preferred to alternative Pagel’s models. We found a greater degree of phylogenetic signal in the climatic niche than in the habitat niche. Overall, squamates exhibited evolutionary lability according to the variation in the habitat structure, thereby suggesting that none of the major subclades is specialized for any specific habitat component.

Emys orbicularis is a semi-aquatic turtle with great longevity being able to reach 50 years. In this study, we estimated the growth rates (in carapace length and body mass) in a population of E. orbicularis from the northeastern Iberian Peninsula over a period of 23 years. We compared their growth rates among age groups, sexes, and years and across different types of habitats (small forest ponds, large forest ponds, and slow-flow streams). We hypothesized that the subpopulation that inhabits the small forest ponds may show slower growth rates because these habitats have lower solar exposure and lower water temperature. The study population showed sexual dimorphism in size, with females being larger and heavier than males. The analyses confirmed that the individuals from small forest ponds are smaller and grow at slower rates. Our results also revealed significant inter-annual variability in the growth rates of E. orbicularis, emphasizing the importance of conducting long-term studies of species with great longevity.

Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions, typically under forest canopies. Here, we assessed whether the insular endemic Salamandra corsica also uses this type of habitat, which could have important implications for its conservation. We used data loggers to record the air temperature and air humidity at 4 h intervals over a period of 2 years, at 13 stations with a confirmed presence of S. corsica. These data were compared with those recorded at Corsican weather stations and those generated by a climate model (WorldClim 2). The weather station data showed significant deviations from the probe data, by an average of − 1.26 °C (minimum temperature), + 2.61 °C (maximum temperature), and − 0.04% (relative humidity). Similarly, the WorldClim 2 data showed significant deviations from the probe data, by an average of − 2.49 °C (minimum temperature) and + 1.69 °C (maximum temperature). These discrepancies reflect the use of densely vegetated and topographically complex habitats by S. corsica, which reduce temperature fluctuations. Overall, our results highlight the importance of natural vegetal cover in the conservation of populations of this endemic salamander.

The Mediterranean region possesses a rich diversity of salamanders, which also exhibit a high degree of ecological diversification. It is assumed that the presence of salamanders is dependent on the level of vegetation cover in terrestrial habitats, but the strength of this association is likely to vary among species. In this study, we investigated the patterns of habitat utilization for Mediterranean salamanders based on 589 records of 33 species. We tested the hypothesis that the association between salamander presence and vegetation density varies among genera or reproductive modes (i.e. terrestrial vs aquatic). The results show that vegetation cover has similar influences on terrestrial and aquatic groups but important differences are identified for lotic and lentic aquatic species. Our findings also indicate that the aquatic lotic, terrestrial, and small-body species deviate significantly from that expected from the background range of variation.

A new subspecies within the Salamandra algira species complex from north-western Africa is described. Previous molecular analysis showed that the populations of S. algira splendens from north-western Morocco consisted of two well supported clades: clade 1 distributed in the Rif Mountains, from Chefchaouen (type locality) to Al Hoceima, and clade 2, located southern from clade 1 being isolated in the northern and central Middle Atlas Mountains. Clade 2 is herein described as a distinct subspecies: Salamandra algira atlanticassp. nov. based on morphological data, allopatric range and molecular divergence. This new subspecies shows an uncorrected pairwise distance of 0.0265 from clade 1 based on cytochrome b DNA sequences. Salamandra algira atlanticassp. nov. is a slender and large sized salamander with a highly variable colouration pattern. It can be distinguished from S. algira splendens by the greater proportion of coral red in the background colouration, being the only known subspecies of S. algira in which coral red can exceed the proportion of black. Variable number (0–5) of yellow to golden yellow dorsal blotches, but usually in lower numbers than the nominotypical subspecies. Salamandra algira atlanticassp. nov. inhabits subhumid to humid forests and karstic systems at mid to high elevations. We briefly discuss the phylogenetic and taxonomic issues among the genus Salamandra which encompasses more valid species than currently recognised.

The Mediterranean stripe-necked terrapin is a freshwater turtle widely distributed in southwestern Europe and northwestern Africa, but whose natural history is little known. In this study we investigated the ecology of a population in northern Algeria (Reghaïa Lake Ramsar Reserve), with special emphasis on its phenology, demographic structure and diet, based on capture and recapture methods. Our results indicated that there is a short inactivity period in January and possibly the activity is also reduced during the month of August. The best Jolly-Seber model indicated that the population within the survey station had a minimum size of 653 specimens. The population contained a higher proportion of males (0.68 - 0.76) and a proportion of juveniles between 0.02 - 0.16. Females were larger and relatively heavier than males. Analysis of stomach contents showed that M. leprosa feeds with high frequency on aquatic arthropods. Specifically, we found insects: Diptera (Chironomidae, Culicidae, Dixidae, Syrphidae), Heteroptera (Corixidae, Notonectidae) and Coleoptera (Dytiscidae), crustaceans (Branchiopoda, Ostracoda), plant matter (Typha angustifolia), fish (Gambusia holbrooki), and unidentified materials.

To identify and evaluate the environmental properties of the Mediterranean islands that make them a suitable habitat for their endemic lizards. This would represent an important improvement in our knowledge and would assist the conservation of these lizards, which are threatened by both the expansion of mainland species and the increasing intensity of human disturbance on these islands. Location Mediterranean Basin. Methods I assessed the environmental associations of 50 species of lizard (19 endemic) across 552 Mediterranean islands using outlying mean index analysis. The strength of the species responses was assessed using binomial generalized linear models. Results The presence of endemic species is positively correlated with the distance of the island from the mainland. Island connectivity is also positively correlated with an increased presence of endemic lizards, but not with an increased presence of mainland species (i.e. those with exclusive or mainly continental natural distribution). In addition, island size, temperature and vegetation productivity are positively correlated with the presence of mainland species. Outlying mean index (OMI) analysis showed that the endemic species occupy niche positions that are similar to the average environmental conditions in the archipelago, but frequently without using the entire range of niches. The mainland species usually occur in more peripheral positions in the environmental space, except for some highly expansive species. Conclusions Lizards that are endemic to the Mediterranean islands were found to be present on a large number of islands within an archipelago, but they quickly disappear as the conditions change, largely because of human activity. Large islands act as population reservoirs for mainland species, facilitating secondary colonization of peripheral islets

Niche conservatism underlies the process of speciation in amphibians on the global scale. However, high tropical diversity is partly attributable to niche shifts within evolutionary lineages. Crocodile newts (genera Echinotriton and Tylototriton) are a monophyletic group endemic to south-east Asia, and are one of the few lineages of urodeles that appear in tropical regions. Here, we examined the patterns of ecological diversification within the crocodile newts based on 207 records of 23 species. The niche space was described according to topographic, climatic variables (temperature, rainfall, and seasonality) and forest cover. Our analysis showed that the occurrence of most of these species was strongly associated with the precipitation regime and seasonality. The diversification patterns of the crocodile newts are complex, showing both conservatism and divergence. These patterns can be related to the Tibetan uplift phase during the Neogene, resulting in the emergence of new montane habitats and subsequent changes in the palaeo-drainage system and climate. The range of ecological diversification within a lineage is possibly the result of several interacting processes, including environmental heterogeneity, the regional climatic history, and physiological constraints on species.

Biotic assemblages are organized according to multiple factors, including environmental filtering and species interactions. However, the roles of abiotic and biotic factors in the organization of amphibian assemblages in arid regions are still not completely understood. Here, I examined the distribution patterns of seven species of amphibians that occur in Tunisia (north-western Sahara Desert) and the composition of 328 amphibian assemblages, including their meta-structural organization. The species showed different responses to environmental gradients, predominantly the aridity and vegetation gradients. The assemblages in xeric regions were composed of nested subsets of the species present in mesic regions. Most of the significant species associations were explained by shared environmental responses, indicating that they can be largely attributed to environmental filtering. The only exception was between two species of generalist bufonids, Bufotes boulengeri and Sclerophrys mauritanica, which showed a residual correlation greater than their shared association with the gradient. In this case, phylogenetic and morphological similarities could favour patterns of mutual exclusion in habitats such as desert oases, where the resources are limited.

This study examined the role of habitat characteristics on the presence of Salamandra algira in the Edough Peninsula, north-eastern Algeria. In this region, 33 sites were surveyed over the late win...

The herpetofauna of north-west Africa includes four species of semi-aquatic reptiles. In north-west Africa, Emys orbicularis and Natrix astreptophora are stenotopic species having fragmented distributions, while Mauremys leprosa and Natrix maura occur throughout the region (eurytopic species). We investigated the factors underlying these distributional patterns and tested the hypothesis that species sharing similar resources tend to be spatially segregated. We characterized the niches of the species based on climatic, topographic, soil texture, landscape and hydrological predictors. The relationship between the presence of a species and the environmental gradient was assessed using distance-based linear models, and habitat suitability was modelled using Random Forests. Our results indicated that both E. orbicularis and N. astreptophora occupy extreme positions within the environmental gradient. Climate and landscape were the major factors influencing the relative occurrences of the stenotopic and eurytopic species. However, these semi-aquatic reptiles are likely to be subject to similar ecological constraints, as their occurrence was positively associated with greater complexity of the drainage system. Thus, there was a high degree of niche overlap between the stenotopic and eurytopic species at large spatial scales.

The alteration of natural flow regimes by hydraulic infrastructure, exploitation for human uses, and changing climates has resulted in significant impacts on native species that inhabit freshwater ecosystems. Hydrologic alteration may promote new opportunities for nonnative species by creating novel habitats, modifying biotic interactions (including predation and competition), and promoting new dispersal pathways. Here, we review the relevant theory and current empirical evidence for additive, synergistic, and antagonistic interactions between hydrologic alteration and species invasions in flowing waters. Building on case studies of both animal and plant communities, we demonstrate the importance of the alteration-invasion nexus to mediate biotic interactions and alter food web structure via top-down and bottom-up effects. Finally, we describe how increasingly altered flow regimes and native-nonnative mixed communities pose a novel conservation challenge, and we explore emerging management strategies in highly-managed river basins.

South-western Europe has a rich diversity of lacertid lizards. In this study, we evaluated the occupancy patterns and niche segregation of five species of lacertids, focusing on large-bodied species (i.e., adults having &gt, 75 mm snout-vent length) that occur in south-western Europe (Italian to the Iberian Peninsula). We characterized the niches occupied by these species based on climate and vegetation cover properties. We expected some commonality among phylogenetically related species, but also patterns of habitat segregation mitigating competition between ecologically equivalent species. We used multivariate ordination and probabilistic methods to describe the occupancy patterns and evaluated niche evolution through phylogenetic analyses. Our results showed climate niche partitioning, but with a wide overlap in transitional zones, where segregation is maintained by species-specific responses to the vegetation cover. The analyses also showed that phylogenetically related species tend to share large parts of their habitat niches. The occurrence of independent evolutionary lineages contributed to the regional species richness favored by a long history of niche divergence.

Trachemys scripta (Reptilia, Emydidae) is among the most widespread invasive reptiles in the world. In general, it is assumed that this species has negative effects on native aquatic turtles based on experiments conducted under controlled conditions. Here, we analysed a 7‒year time series (2013‒2019) of data from captures of three species of turtles (two natives and one alien) from natural populations in the northeastern Iberian Peninsula. We evaluated (i) the interspecific spatial overlap and (ii) the correlation between the scaled mass index (SMI) of the native turtles and the abundance of T. scripta, including an interaction effect between the species. The analyses revealed that T. scripta has relatively low spatial overlap with Emys orbicularis but high overlap with Mauremys leprosa. Overall, the abundance of T. scripta was not associated with significant variations in the SMI of the native species, although for the female E. orbicularis, we detected a negative trend. The analyses also indicated that the abundance of T. scripta does not have an additive effect on the SMI of other turtles, even if there is a negative effect between native species. These findings suggested that the impact of T. scripta on other turtles could be density-dependent.

The ecological role of anuran larvae is usually defined as a primary consumer. Recent studies have shown, however, that some grazing–rasping species consume animal matter on a regular basis. We investigated zoophagy in two species of Spade-foot Toads (Pelobates cultripes and Pelobates varaldii). The larvae of both species showed no specific morphological adaptations for macrophagy but are very large and inhabit invertebrate-rich ponds under prolonged summer drought conditions. We hypothesized that both species would consume animals having high nutritional value, and that there would be no difference between the two species in terms of the animals consumed, because tadpoles are broad dietary generalists. We also hypothesized that the consumption of animals would vary during development based on the size limitations of the oral cavity. Examination of the intestinal contents of P. varaldii and P. cultripes indicated that they had consumed a wide range of invertebrates, as predicted. Differences in ...

Pleurodeles poireti is one of the lesser-known amphibians in the Mediterranean region. This species is strictly endemic to the Edough Peninsula in northeastern Algeria. Here we investigated the factors that determine the presence of P. poireti, by affecting its selection of both aquatic and terrestrial habitats. Aquatic habitats were characterised according to their morphology and the physicochemical parameters of the water. We also examined the topographical and substrate features, plant cover and climatic conditions at the occurrence sites. Our surveys indicated that P. poireti is widely-distributed on the Edough Peninsula. Pleurodeles poireti predominantly breeds in moderate to large water bodies densely covered with emergent vegetation. The water parameters are less influential in its selection of breeding sites, except dissolved oxygen and turbidity, which are usually high at the occupied sites. At the broad spatial scale, P. poireti is positively associated with lowlands in cultivated landsc...

Reptiles are a successful group in subtropical arid regions. However, little is known about the drivers that influence the diversity of arid reptile communities. One approach is to investigate the variation in phylogenetic structure of the communities along a broad environmental gradient. In this study, I investigated these patterns in the communities of lacertids at the periphery of the Sahara Desert in Tunisia. The effect of the environment was assessed based on a set of variables describing the climate, topography, substrate and cover of perennial vegetation. The phylogenetic alpha diversity was described using the mean pairwise distance (MPD) and the mean nearest taxon distance (NTD) metrics. The analyses showed that the lacertid species could be clustered into three main ecological groups: mesic (Podarcis vaucheri, Psammodromus algirus, Psammodromus blanci, Timon pater), xeric (Acanthodactylus blanci, Acanthodactylus boskianus, Acanthodactylus maculatus, Mesalina olivieri, Ophisops occidentalis), and hyperxeric (Acanthodactylus dumerilii, Acanthodactylus longipes, Acanthodactylus scutellatus, Mesalina guttulata). The analyses also indicated that environment had a weak influence on species richness (15.7% of explained variance), but a strong effect on the phylogenetic (76.5% NTD, 89.5% MPD) structure. The lacertid communities tended to be phylogenetically clustered on sandy substrates under arid climate conditions, and overdispersed under more humid climatic conditions.

The composition of Urodela assemblages is regulated by macro- and microclimatic conditions and by the interactions established between ecologically analogous species. Species of the North African Urodela are distributed unevenly; some species have large ranges whereas others occur in fragmented populations or in restricted ranges. We examined the niches occupied by these species to determine the factors that regulate their range patterns. The niches were examined at two spatial levels; regionally, using climatic and vegetation cover data, and locally by studying the selection of aquatic habitats. Our results indicate that Salamandra algira (North African fire salamander) and North African Pleurodeles species are segregated along a thermal and vegetation cover axis, although with considerable overlap. The fragmentation observed in the distribution of the North African Urodela is caused by prevailing arid conditions in the region. The three Pleurodeles species appear under similar climate condition...