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We summarize, here, the results from several studies conducted over many years on several endemic species of lizards (genus Gallotia) from the Canary Islands. Quantitative analyses show clear differences both among the species of every island and populations within each species. Sexual dimorphism exists in all analysed species, and a phylogenetic analysis shows that the degree of dimorphism did not change along the evolutionary history of the Canary Islands: species with large and small body sizes have a similar degree of sexual dimorphism, with male body size changes closely following those undergone by females. In G. caesaris (from El Hierro and La Gomera islands) and in G. stehlini (from Gran Canaria), longer hind limb length was correlated with more open habitats. Within most species, males are more conspicuous than females, mainly in terms of body size, behaviour and coloration pattern. Lateral colour spots are blue in most species and green in others. In G. galloti from Tenerife, male lateral spots have larger spot areas and percentage of reflectance in the ultraviolet/blue part of the spectrum than females. This trait shows a monthly variation along April to July, both in males and females, its magnitude being larger in May–June. Behaviour analysis, especially in the last species, shows a great diversity in behaviour patterns, and analysis of intrasexual male competition revealed that contest outcome depends on several morphological and colouration characteristics but mainly on the individual’s behaviour. Detailed behavioural analyses were useful for managing a few captive individuals of the highly endangered G. bravoana from La Gomera island. Experimental analyses of some behaviours in the endemic Hierro island lizard (G. simonyi, in danger of extinction) show that individuals may learn to recognize predator models and increase their running speeds with training.

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A striking new sandveld lizard of the Nucras tessellata group is described from the Lambert`s Bay Strandveld of the Western Cape Province, South Africa. It is sister to the clade N. livida + N. tessellata, and is phenetically most similar to N. tessellata, from which it differs in its more elongate body and possibly increased number of presacral vertebrae and pat-ternless orange dorsal coloration. The form elegans, described as a species by Andrew Smith (1838), but treated as an infrasubspecific variant by Broadley (1972), also exhibits weak patterning, but is likely a regional color variant. Nucras aurantiaca sp. nov. is the ninth member of the genus found in southern Africa. Its discovery in the well-collected coastal Western Cape suggests that further herpetofaunal surveys are needed in this region, which is threatened by agricultural activity and tourism-related development.

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Lizard populations have been traditionally considered unusually stable. However, there are very few examples to verify this hypothesis on long-term studied populations. Over almost four decades, we have obtained long time series of the abundance of Lilford’s Wall Lizard, Podarcis lilfordi, from all known populations of Menorca (Balearic Islands, Spain). Lizard densities were estimated from line transects data using N-mixture models. Irregular time series were then checked for the presence or absence of a monotonic trend and for density dependence of each population. With multiple regression models we studied the relationship between weather events and the annual abundance of lizards. Density dependence was detected only in two populations: Addaia Petita and Binicodrell Gros. The analysis with EGSS and OUSS models, as well as the results with a Bayesian analysis, showed that most populations seem stable over the years, with a positive and statistically significant trend in five of the 17 populations under study. Only on Sanitja Island the population of lizards exhibits a significantly negative trend. Weather events have a very variable influence on each of these populations. In two small islets, Mel and Ses Mones, the annual number of cloudy days have a negative effect on the abundance of lizards. In Bledas Island, with an exposed geographical situation, we observe a significantly negative effect of all three weather events considered: storms, cloudy days and strong winds. Surprisingly, in Aire and Addaia Gran islands, the annual number of days with storms had a significantly positive effect, probably because the marine subsidies contributed to trophic availability of these two islands by the storms. This work is a first attempt to establish the real abundance of this species, its long-term trend and the influence of weather events on densities of a large set of populations. The relevance of weather events is strongly different on each population and depends on environmental conditions of each population, especially lizard abundance itself, the island surface, geographical location and degree of exposure to weather events.

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Although rapid adaptive changes in morphology on ecological time scales are now well documented in natural populations, the effects of such changes on whole-organism performance capacity and the consequences on ecological dynamics at the population level are often unclear. Here we show how lizards have rapidly evolved differences in head morphology, bite strength, and digestive tract structure after experimental introduction into a novel environment. Despite the short time scale (_36 years) since this introduction, these changes in morphology and performance parallel those typically documented among species and even families of lizards in both the type and extent of their specialization. Moreover, these changes have occurred side-by-side with dramatic changes in population density and social structure, providing a compelling example of how the invasion of a novel habitat can evolutionarily drive multiple aspects of the phenotype.

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The joint expression of particular colors, morphologies, and behaviors is a common feature of adaptation, but the genetic basis for such “phenotypic syndromes” remains poorly understood. Here, we identified a complex genetic architecture associated with a sexually selected syndrome in common wall lizards, by capitalizing on the adaptive introgression of coloration and morphology into a distantly related lineage. Consistent with the hypothesis that the evolution of phenotypic syndromes in vertebrates is facilitated by developmental linkage through neural crest cells, most of the genes associated with the syndrome are involved in neural crest cell regulation. A major locus was a ~400-kb region, characterized by standing structural genetic variation and previously implied in the evolutionary innovation of coloration and beak size in birds. We conclude that features of the developmental and genetic architecture contribute to maintaining trait integration, facilitating the extensive and rapid introgressive spread of suites of sexually selected characters.

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Conspicuous body colors and color polymorphism have been hypothesized to increase rates of speciation. Conspicuous colors are evolutionary labile, and often involved in intraspecific sexual signaling and thus may provide a raw material from which reproductive isolation can easily evolve, while polymorphism could favor rapid evolution of new lineages through morphic speciation. Here, we investigated the influence of the presence/absence of conspicuous colorations, and of color polymorphism on the speciation of Lacertids. We used several state-dependent diversification models, and showed that, regardless of the methods, conspicuous colorations and color polymorphism were not related to species speciation. While the lack of correlation between conspicuous colorations and speciation rates is in line with most of the literature testing this hypothesis, the results for color polymorphism contradict previous studies, and question the generality of the morphic speciation hypothesis.

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Body colouration is involved in multiple aspects of species ecology and behaviour. Melanism, a common colour polymorphism, has been associated with camouflage and thermoregulation, particularly in diverse, high-altitude habitats of arid regions. This study reports the first case of melanism in the lacertid Acanthodactylus boskianus, two scorpions, Leiurus haenggii and Compsobuthus manzonii, and the first records of brown-black melanistic colouration in three rodent species, Acomys dimidiatus, Meriones crassus, and Sekeetamys calurus, in the dark lava fields (harrat) of north-western Saudi Arabia. Additionally, it expands observations of melanism in the endemic colubrid Rhynchocalamus hejazicus and provides the first documented records of brown-black melanistic Acomys russatus for the region, consistent with earlier predictions. These observations suggest that colour polymorphism may serve a cryptic function through background matching in both diurnal and nocturnal species, but other roles of melanism should be further investigated. Despite their extent, lava fields in arid regions remain poorly studied due to their remoteness and limited accessibility, yet they offer unique opportunities to investigate phenotypic evolution in arid ecosystems.

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Genetically determined color morphs are found in many animals. Polymorphism can be maintained by social selection if competitive interactions allow each morph to increase in frequency when rare. This reliance on negative frequency–dependent selection should make color polymorphism vulnerable to the appearance of novel phenotypes that disrupt competitive interactions among morphs. We show that the origin and adaptive spread of a sexually selected syndrome in common wall lizards (Podarcis muralis) selectively eliminates alleles coding for alternative color morphs that have been maintained for millions of years. The results demonstrate how the arrival of a novel phenotype can disrupt balancing selection, providing a link between rapid phenotypic evolution and the loss of color polymorphisms.

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Tooth complexity has long been known as a powerful indicator of feeding in mammals and reptiles, often used to infer diets of long-extinct species. However, how these trends are established below the species level remains unclear. Here, we take an orientation patch count rotated (OPCR) approach to quantify tooth complexity across eight populations of Podarcis pityusensis, an insular omnivorous lizard endemic to the Pityusic Islands of the Western Mediterranean. These populations vary widely in their extent of herbivory and specialization, which we use to assess the link between complexity and diet. We find that increasing herbivory is matched by increasing dental complexity, with effect sizes comparable to those found on the macroevolutionary scale. We do not, however, find clear evidence of divergence of tooth complexity between sexes within populations (in a way that would be consistent with niche divergence), meaning that the extent to which this trait is plastic remains controversial. Our results suggest that dental complexity is a highly powerful metric to infer diet and an informative candidate for linking micro- and macroevolutionary patterns.

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Die im Mai 1988 während einer dreiwöchigen Exkursion durch Algerien beobachteten Eidechsen werden in diesem zweiten Bericht über die Reise durch die Maghreb-Staaten vorgestellt.

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Aus Anlass der 100. Wiederkehr des Geburtsjahres des russischen Herpetologen Prof. Dr. ILJA S. DAREWSKIJ 2024, das mit dem 300-jährigen Jubiläum der Russischen Akademie der Wissenschaften in St. Petersburg zusammenfällt, wird das lacertidenkundliche Wirken dieses bedeutenden Forschers gewürdigt. Besondere Aufmerksamkeit gilt dabei den Bezügen nach Deutschland und speziell nach Bonn.

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Der Artikel berichtet über den Nachweis einer dunklen Farbmorphe der Griechischen Spitzkopfeidechse (Hellenolacerta graeca) aus dem südöstlichen Peloponnes. Zudem wird die mögliche selektive Rolle einer dunklen Färbung diskutiert.

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Bahnstrecken gehören zu den wichtigsten Sekundärlebensräumen der Zauneidechse (Lacerta agilis). Zur Aufrechterhaltung des Bahnbetriebs sind jedoch regelmäßige Eingriffe an Bahnstrecken notwendig, welche eine Gefahr für lokalen Zauneidechsenpopulationen sein können. Um mögliche Bedrohungen durch Instandhaltung und Bauarbeiten einschätzen zu können, sind detaillierte Kenntnisse darüber erforderlich, wie Zauneidechsen ihren Lebensraum entlang von Bahnstrecken nutzen. Daher haben wir in den Jahren 2020 und 2021 die Aktionsräume von Zauneidechsen mit Hilfe von Radiotelemetrie untersucht und festgestellt, ob sich diese zwischen den Jahreszeiten und den Geschlechtern unterscheiden. Zudem haben wir die an Bahnstrecken vorhandenen Mikrohabitate einschließlich der Schlafplätze der Eidechsen untersucht. Die Datenaufnahme wurde in Brandenburg durchgeführt. Im Ergebnis zeig te sich, dass die Aktionsräume von Zauneidechsen im Frühjahr nach der Winterruhe am kleinsten und im Sommer am größten sind. Unterschiede in der Größe der Aktionsräume zwischen Männchen und Weibchen waren nicht signifikant. Die Größe des Aktionsraums ließ sich am besten durch die Kalenderwoche vorhersagen, da in warmen Sommermo naten im Schnitt größere Aktionsräume verzeichnet wurden als im Frühjahr und Spätsommer. Die Kernlebensräume der einzelnen Tiere befanden sich direkt entlang der Bahnlinie. Die meisten Schlafplätze wurden in der Böschung und im Gleisschotter festgestellt. Insbesondere im Sommer stellte der Schotter den meistgenutzten Schlafplatz dar, während sich die Schlafplätze im Frühjahr und Spätsommer hauptsächlich in der Böschung und am Waldrand befanden. Unsere Studie zeigt, dass Bahngleise und die angrenzenden Böschungen eine hohe Strukturvielfalt aufweisen und damit ganz jährig von Zauneidechsen besiedelt werden können, während die genaue Lebensraumnutzung je nach Jahreszeit va riiert. Darüber hinaus geben wir detaillierte Einblicke in die Nutzung verschiedener Mikrohabitate als Versteck- und Schlafplätze.

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The results of our laboratory hybridization of green-bellied (Darevskia chlorogaster) and Caspian (Darevskia capsica) lizards are presented. When crossing D. chlorogaster females and D. caspica males, 7 hybrid individuals were obtained. The newborn lizards had body lengths of 24.59–27.11 mm and masses of 0.32–0.37 g. Incubation lasted 57–61 days. After the first period of hibernation (286–357 days after leaving the eggs) the hybrids had their first attempts at mating and laying eggs. An individual with a body length of 25.73 mm and a weight of 0.38 g was obtained from one such clutch, which soon died. The authors suggest that the studied combination of hybrids may be characterized by impaired reproductive function.

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The paper presents a comparative analysis of the growth rates and characteristics of 10 lizard species from the genus Darevskia (D. armeniaca, D. arribasi, D. brauneri, D. caucasica, D. daghestanica, D. derjugini, D. mixta, D. pontica, D. raddei, and D. valentini) in laboratory conditions. It has been shown that lizards from different species complexes, but originating from close localities, are characterized by similar growth features. Lizards from Western and Central Transcaucasia (D. brauneri, D. derjugini, D. mixta, and D. pontica), despite their different ecological niches, are characterized by the lowest feed costs per unit weight gain and the highest mass accumulation coefficients compared to animals from the North Caucasus (D. caucasica and D. daghestanica) and the Armenian Highlands (D. armeniaca, D. raddei, and D. valentini).

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The results of our study of age and growth of the Eastern slowworm (Anguis colchica) in two localities in the east of the Lesser Caucasus are presented. 33 individuals (18 males and 15 females) from the vicinity of Stepanavan town (Lori Marz, Armenia) were studied. A sample from the vicinity of Zanavi village (Borjomi municipality, Samtskhe-Javakheti region, Georgia) contained 19 specimens (6 males and 13 females). The body length of captured animals was measured and the tip of the tail was clipped. The mandibular dental bone was also extracted from Stepanavan individuals killed on the motorway. The tail vertebrae and tooth bones of slow worms were shown to produce an equal number of stopped growth lines. The age of females from Stepanavan ranged from 2 to 6 years (mean 4.33±1.35) and males 3 to 7 years (mean 4.72±1.13), respectively. Males and females did not differ statistically significantly in their mean age. The females from Zanavi were 3–7 years old (mean 4.67±0.89) and males 3–6 years old (mean 4.67±1.04), respectively. Lizards from Armenia and Georgia did not differ in their mean age. In Stepanavan, males were significantly larger than females, while in Zanavi they did not differ. Females from Zanavi were larger than females from Stepanavan, and males from Stepanavan were larger than males from Zanavi.

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Our sex ratio analysis of mature individuals in populations of 5 lizard species, genus Eremias (Lacertidae) and genus Phrynocephalus (Agamidae), during the breeding season has shown that males predominate in the genus Eremias in most cases, while females predominate in the genus Phrynocephalus. This fact is confirmed by data collected by other researchers on 14 more species of the indicated genera. The authors believe that this difference is due to some ecological features of the noted systematic groups. The predominance of males in the Eremias populations is probably determined by the high activity of males and the greater probability of becoming a victim for predators. In this case, a significant number of males serves as an additional mechanism for maintaining the necessary 1:1 balance of mating partners during the breeding season. The predominance of females in the Phrynocephalus populations is most likely determined by peculiarities of the spatial structure, namely: several females usually live in a male’s territory, which generally increases the chance of a larger number of females participating in reproduction. Thus, the corresponding differences in the sexual structure apparently serve as mechanisms for optimizing the success of the breeding season.

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We reevaluate the recent species description of Holaspis ngalangi from Angola by Parrinha et al. (2025), which was based solely on variable morphological characters, through comparative analysis of specimens across the genus’ range, including material previously examined but not reported by the original authors. Our analysis demonstrates that the proposed diagnostic traits of this species (precloacal scale morphology and ventral scale arrangement) are hyper- variable within both H. guentheri and H. laevis, showing neither biogeographic nor morphological consistency. Notably, specimens from Angola’s Dundo Museum, though examined by Parrinha et al. (2025), were omitted from their analysis despite exhibiting the same variable characteristics, strongly indicating these represent intraspecific variation rather than diagnostic species-lineage features. Consequently, we formally place Holaspis ngalangi Parrinha, Marques, Gonçalves, Tuitenko, Bauer & Ceríaco, 2025 as a junior synonym of Holaspis guentheri Gray, 1863, representing the second recent case of an Angolan reptile species description based solely on morphological data being synonymised within the last decade. These repeated cases highlight the inherent risks of morphology-only taxonomy, particularly when: (1) diagnostic characters show extensive overlap among taxa, and (2) multiple lines of evidence are not incorporated. Our findings also emphasize the critical need for robust, integrative species delimitation approaches in understudied regions like Angola, where high levels of cryptic diversity and phenotypic plasticity are likely to complicate taxonomic assessments.

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The members of the Afrotropical lacertid genus Holaspis are strikingly specialized lizards, adapted for gliding in forest canopies, with serrated blue tails. Two species are currently recognized within the genus: Holaspis guentheri from West and Central Africa, and Holaspis laevis from East Africa. The currently known southern limits of H. guentheri are in the northern Angolan Guineo-Congolian habitats, which are remnants of forests connecting the country to West/Central Africa. The oldest record of the species in Angola, dating back to the 19th century, is based on a currently lost specimen collected by José d’Anchieta near Caconda, southwest Angola. Caconda is situated on the Angolan Central Plateau, which is part of the Great Escarpment of southern Africa. The loss of Anchieta’s specimen and its geographic context led most authors to disregard it, leaving its taxonomic identity dubious until now. The rediscovery of two additional specimens from Caconda, collected by William John Ansorge in the early 20th century and deposited in the Natural History Museum, London, allowed us to confirm the presence of the genus in the region, prompting targeted surveys and examination of additional material. Our surveys failed to locate any Holaspis near Caconda, with alarming rates of deforestation in the region raising the possibility that this population may already be extinct. The reexamination of the extant Caconda specimens and comparison with H. guentheri and H. laevis revealed consistent morphological differences that suggests that the Caconda population may represent a distinct taxonomic unit. Here we describe the Holaspis from Caconda as a new species, presumably endemic to the Angolan Central Plateau. These findings and their implications are discussed in the biogeographical context of the highlands of western Angola, a recognized hotspot of diversity and endemism for several taxonomic groups.

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The Nucras of the eastern Zambezi River basin region, comprising Zambia, Malawi and central Mozambique have been poorly studied. We re-evaluated the type specimens of Lacerta cameranoi Bedriaga, 1886 and L. tessellata pseudotessellata Bedriaga, 1886, both collected at Tete, Mozambique by Wilhelm Peters in the 1840s. Both are assignable to N. ornata, the most widespread Nucras in the region. However, an additional specimen collected from Tete is referrable to N. holubi, filling a collecting gap for this species between central Zimbabwe and southern Malawi. Nucras records from northeastern Zambia include several N. boulengeri, two photo-vouchered records, one unidentifiable and the other an enigmatic form not consistent with any known species, and a new species from Senga Hill, Northern Province. The new species, Nucras margaritae sp. nov., is known only from its holotype. It is morphologically similar to N. ornata, from which it is separated by 620 airline km, but is deeply genetically divergent from all congeners and is sister to the clade comprising N. holubi, N. ornata, N. damarana and N. intertexta. At least five species of Nucras, four currently named, inhabit the greater eastern Zambezi River basin.

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Iberolacerta martinezricai, the Batuecan lizard, is the reptile species with the most restricted distribution in continental Europe, confined to a few rocky scree habitats in the Sierra de Francia, Spain. During the study period of 2018 (22 days of fieldwork from May to October), a total of 67 localities (30% more than in 2007 censuses) were surveyed. Of these places, 30 (44.77%) were positive for the presence of the species. The mean density of specimens per hectare was 41.44 (53.68 ind.ha, considering only the most favorable places), which gives a total estimation of 4140 specimens for the species (undoubtedly an overestimated value). The screes with presence of the species tend to be larger in surface, located at an higher average altitude (1300 – 1700 m), with a lower slope, greater average stone size, higher moisture and presence of lichens and mosses, and with a greater weight in the connectivity of the network of all the screes in the study area. A modeling analysis of the potential distribution of the species (156 potential sites) was performed. This model indicates the probable presence in 89 (57.05%) and very probable presence in 64 (71.91%) of the 89 remaining places. Of the 64 very probable places, 39 have been sampled in the 2018 census. Of those 39, the species was really present in 27 (69.23%), which would indicate a good fit for the model. The model has allowed the identification of 35 new scree sites where the presence of the species is very probable (25) or probable (10) to be sampled in future.

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Our article presents the most comprehensive data on ticks and mites parasitizing lizards of the genus Eremias. We provide the revised data on both host and ectoparasite taxonomy according to the most up-to-date information. Nine species of ectoparasites have been documented in the Caucasus region and Iran, including Haemaphysalis punctata, Haem. sulcata, Haem. parva, Hyalomma marginatum, Hyal. aegyptium (reported for the first time), Ophionyssus saurarum, Odontacarus armeniensis, Ericotrombidium caucasicum, Pentidionis angulata. Compared to lizards of the genus Darevskia and Lacerta, racerunners exhibit approximately equal levels of infestation.