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Animals inhabiting arid environments use a variety of behavioural and physiological strategies to balance their water and salt budgets. We studied the effects of dehydration and salt loading on osmoregulatory capacities in a large herbivorous desert lizard, the Moroccan Spiny-tailed lizard Uromastyx nigriventris, the family Agamidae. These lizards select plants with a high K+ to Na+ ratio of 15 to 20, and like other herbivorous lizards, effectively eliminate the extra electrolyte load, mainly via a pair of active nasal salt glands, which exude the extra ions from blood. Here we present results of a series of laboratory experiments, which tested a five-week food and water deprivation and the excretory response of nasal salt glands, during a short period of five days, following salt loading by two separated injections of KCl or NaCl at a 5-day interval (4th and 9th days). During food-water deprivation, hypohydrated lizards lost 32% of their initial body mass with a substantial decrease of their Body Condition Index and the tail volume as an index of energy (fat and then potential metabolic water) storage. Plasma osmolality significantly increased by 20%. There were also significantly increased plasma sodium, chloride, and total protein concentrations. On the other hand, there was no significant decrease in the plasma glucose level. Most of the salt loaded lizards secreted far more K+ than Na+ via the nasal glands, even after NaCl loading. The K+/Na+ ratio decreased only after two to three repetitive NaCl injections but insufficient Na+ was eliminated. Two successive KCl injections were successfully eliminated, but daily natural average K+ administration induced progressive hyperkaliemia. These experimental data agreed with previous observations showing variations of plasma Na+ and K+ concentrations in free-living lizards. The nasal gland constitutes the main route of Cl− excretion but the Cl−/(Na+ + K+) ratio may vary according to observations in other herbivorous species.

We analysed the interindividual variation in diet, patterns of food resource use and topology of the trophic networks of juvenile, male, and female Ameivula ocellifera (Spix, 1825) during one year, covering wet and dry seasons. Using a network-based approach, we evaluated the degree of variation in the diet of individuals, and the degree of nestedness and clustering to identify patterns of resource use and the topology of individuals food webs. We found a high degree of interindividual variation in the diet of juveniles, males, and females during the study period, which seems to be related to nested patterns of resource use of males and females. These results also suggest that males and females seem to have both generalist and specialist individuals, of which the diets of specialists are nested within the diets of generalists. For juveniles, we found evidence of interindividual variation in diet in both seasons, although patterns of food resource partition that may cause it could not be identified. Insect larvae of several groups were the main food resource in all three lizard groups during the wet season, while termites were the dominant food item during the dry season. Our results conform to the Shared Preferences Model where individuals should consume the same top-ranked prey when they are abundant in the environment, replacing it with suboptimal items as preferred ones become scarce.

The relationship between the numbers of smooth snakes, Coronella austriaca, and common lizards, Zootoca vivipara, was investigated in a 6.5 ha area of lowland heath within Wareham Forest in southern England. With the exception of 2002 the numbers of lizards, small mammals and individual smooth snakes captured, or observed, were recorded during each of 21 annual surveys between May and October 1997-2018. Smooth snake diet was investigated annually between 2004 and 2015 by analysing faecal samples and showed that lizards, particularly the common lizard, and pigmy shrews, Sorex minutus, were important prey species. There was no significant correlation between the occurrence of any small mammal species and either snake numbers or their presence in smooth snake diet. Over the study period there was an overall decline in the number of smooth snakes captured whilst there was an overall increase in the number of common lizard sightings. The frequency of common lizards found in the diet of smooth snakes was positively correlated with their abundance within the study area. There was a significant correlation between the decline of smooth snake numbers and the subsequent increase in the number of common lizard sightings suggesting that lizard abundance may be controlled by snake numbers. Conversely, we found no evidence indicating that smooth snake numbers were dependent on lizard numbers suggesting that factors other than prey availability e.g. habitat change due to cattle grazing, blocking ground water drainage ditches, or climatic variables, were impacting on snake numbers, particularly between 2012 and 2018.

Recent biological discoveries have changed our understanding of the distribution and evolution of neotropical biotas. In the Brazilian Atlantic Forest, the discovery of closely related species isolated on distant mountains has led to the hypothesis that the ancestors of montane species occupied and dispersed through lowland regions during colder periods. This process may explain the distribution of an undescribed Anolis lizard species that we recently discovered at a montane site in the Serra dos Órgãos National Park, a popular tourist destination close to the city of Rio de Janeiro. To investigate whether this species is closely related to other Atlantic Forest montane anoles, we implement phylogenetic analyses and divergence time estimation based on molecular data. We infer the new species nested within the Dactyloa clade of Anolis, forming a clade with A. nasofrontalis and A. pseudotigrinus, two species restricted to montane sites about 400 km northeast of Serra dos Órgãos. The new species diverged from its sister A. nasofrontalis around 5.24 mya, suggesting a cold-adapted lowland ancestor during the early Pliocene. Based on the phylogenetic results, we emend the definitions of the series taxa within Dactyloa, recognizing a clade containing the new species and several of its relatives as the nasofrontalis series. Lastly, we provide morphological data supporting the recognition of the new species and give it a formal scientific name. Future studies are necessary to assess how park visitors, pollutants, and shrinking montane habitats due to climate change will affect this previously overlooked anole species.

The consequences of past or future climate change have been studied in many physical and biological systems, and their effects could change the ecology and spatial distribution of suitable areas for a wide variety of organisms. We analyzed the environmental and geographic space of the current suitable area projecting these conditions into Mid-Holocene and 2050 RCP8.5 scenarios to quantify whether climate change would affect the distribution and size of environmental and geographic space for lizard species of the genus Teius. The potentially suitable geographic area for the Mid-Holocene was found to be smaller than today for T. oculatus (-29.55%) and for T. teyou (-6.82%), but for T. suquiensis it was inferred as a larger suitable area (+26%). For the future scenario all species showed a decrease in the potentially suitable area compared to the present (T. oculatus = - 9.30%, T. teyou = - 0.79%, T. suquiensis = - 37.58%). The PCA axes that in the environmental space showed a higher contribution for PC1-2 in Mid-Holocene and Present were mostly related to temperature and for PC3 with altitude variables, for the 2050 scenario were temperature for PC1, precipitation for PC2 and altitude-temperature for PC3. The current Teius' potentially suitable geographic space results versus the other temporal forecasts, showed specific differences in magnitude changes. This work illustrates how ectothermic organisms might have to face major changes in their environmental and geographic space as a consequence of the effect of climate changes. Fil: Minoli, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina Fil: Cacciali Sosa, Pier. Instituto de Investigación Biológica del Paraguay; Paraguay. Asociación Guyra Paraguay; Paraguay Fil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina Fil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina

Ambient temperature is a primary factor affecting the physiology and activity of reptiles. Thermoregulation involves a series of mechanisms to maintain an organism’s body temperature within a narrow range. The study of thermal ecology of lizards is relevant for understanding their distribution, life history, ecology and thermal requirements. Moreover, determining how species are able to attain physiologically active body temperatures in challenging environments is necessary for assessing the risk of extinction due to climate change, especially for threatened endemic species. We evaluated and compared the thermal ecology of two populations of the viviparous lizard Barisia imbricata, at contrasting elevations (2200 and 3700 m). We obtained variation in thermal data from winter through autumn for multiple years. We determined thermal efficiency indices based on field active body temperatures, preferred temperatures (in a thermal gradient), and operative environmental temperatures (according to null models). We also recorded substrate and air temperatures at the time of capture. Mean body temperature of both populations showed a positive correlation with environmental temperatures. We found significant seasonal differences in body temperature in both populations, and between body temperatures of the two populations. Our results suggest that B. imbricata is an eurythermic species and can thermoregulate actively at any given time. However, when environmental temperatures are within the range of preferred temperatures, the species does not engage in thermoregulatory behavior. This information expands knowledge on the range of possible thermal responses to environmental variation within a species.

Escape behaviour is a common antipredator strategy of lizards. Here, we studied the effect of several variables predicted to have a potential effect on escape behaviour of lizards. Specifically, we measured the effects of starting distance (SD), distance to cover, sex–age and the observer’s head orientation on flight initiation distance (FID) in the common agama Agama agama. Agamas were approached in urban localities in Limbe city, Cameroon, where they were habituated to the presence of humans. We found no association between FID and SD, but individuals closer to potential cover had shorter FID than individuals farther from a refuge. Juveniles escaped later than adults, but no significant differences were found in the FID between adult males and females. Head direction of the approaching observer had no effect on FID. This is, to the best of our knowledge, the first study investigating factors affecting FID in common agamas, extending our knowledge of risk-related behaviour in lizards of the Old World tropics.

The present study sought to determine whether the defense mechanisms of termites influence the rate of consumption by lizards, and if that pattern differs between lizard species. Termites with different defense mechanisms (mechanical and chemical) were offered to two species of lizards from different lineages (Tropiduridae and Teiidae). We found that termites that used defensive chemicals were less likely to be eaten by lizards of both lineages. Our results indicate that lizards from both lineages are capable of selecting termites based on their defense mechanisms. As a result, there is no apparent direct link between the rate of termite consumption and their abundance in the ecosystem. Therefore, the use of stomach contents as a proxy to measure prey availability may render a bias estimation of termite abundance in the environment.

We calculated growth rate for the spiny-footed lizard (Acanthodactylus erythrurus) inhabiting coastal eastern Spain from long-term mark-recapture data. Growth curves differ between sexes, with males growing faster than females and achieving larger size maximums. In this population each sex reaches maturity at about 300 days of age, approximately 34% faster than males, and 28% faster than females studied in a population further south and west in Iberia. Our logarithmic growth model has an accuracy of 96.8% and high statistical significance ( for males and for females). Although both the exponential curve of “best fit” for growth estimated for males (), and the linear curve of “best fit” estimated for females () in a population from Cádiz (Busack and Jaksic, 1982) are also significant. The overlap between growth curves and the general data cloud of the population showed that at the end of the year the proportion of individuals younger than one year was 80% and the proportion of individuals older than one year was 20%. Our data, in agreement with calculated maximum life spans for males (1.9 years) and females (2.1 years) in Cádiz, suggest a life span of approximately two years for both sexes. Females seem to reproduce only in a unique season in their lives, at this locality, as in Cádiz (Busack and Klosterman, 1987) they likely lay only one clutch, whereas females in Morocco (Bons, 1962) may produce two.

Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat’s UV reflection might have a cost infringed by conspicuousness.

We studied the thermal biology of the meadow lizard (Darevskia praticola) in the peripheral part of its distribution range (westernmost edge of the distribution area). We assessed whether these lizards actively thermoregulate, estimated the accuracy and effectiveness of thermoregulation, and evaluated the thermal quality of the habitat using the standard thermal parameters: body (), preferred () with set-point range () and operative temperatures (). of the meadow lizard under controlled laboratory conditions was between 27.8°C and 31.4°C. In the field and averaged 29.0°C and 26.1°C, respectively. A large proportion of s fell below the range of the meadow lizard, and lizard s were substantially closer to the species’ range. Obtained values of thermoregulatory indices suggested that the meadow lizard thermoregulated actively, with a rather high accuracy () and effectiveness ( and ), and that their habitat at this locality was thermally favourable during the spring. Our results suggest that thermal requirements of the meadow lizard resemble those of alpine lacertids, while their s and are lower than in most lacertid lizards. Further thermoregulation studies could be an important step in predicting the impact of the global climate change on the meadow lizard and the risks of local extinctions of its peripheral populations.

Food habits of the Moroccan Spiny-tailed lizard, Uromastyx nigriventris, from three localities along an aridity gradient from north-east (Mediterranean) to southwest (Atlantic pre-Saharan) of the Atlas range, Morocco, were investigated in spring and autumn 2015 using fecal microhistological analysis. The obtained results showed that these lizards are predominantly herbivorous feeding on 4 to 13 different plant species depending on locality and season, but some insects, namely coleopterans and ants (Formicidae) (up to 6%) are also consumed. They heavily ingested annual and perennial herbaceous plants through a single season. There were significant differences among seasons and localities in terms of species richness and Shannon-Wiener diversity indexes. These indexes increased significantly, respectively for the spring and autumnal diets, and correlatively with the species richness in the habitat along the aridity gradient. The Stress-Gradient Hypothesis could explain this increase. According to Pianka’s niche overlap index (), dietary overlap was low between Saka (the least arid locality) and Skoura (the intermediate locality) in spring. Conversely, there was a substantial overlap in the diets in autumn with a more pronounced similarity between Saka and Skoura. A review of published information on food habits among Spiny-tailed lizard species and populations was established.

Tail autotomy is a common phenomenon in lizards that increases the chances of immediate survival during a predation event or agonistic encounter. However, despite short-term benefits, tail regeneration may also impose costs. Several studies have demonstrated that tail loss compromises other vital functions such as lipid storage, reproduction, and the immune system. Several lizard species are hosts of mites and ticks. Here we evaluated in three lizard species from the genus Sceloporus, whether individuals that have lost their tails and invested energy in tail regeneration are more susceptible to ectoparasites. Using a multimodel inference framework, we examined if tail loss and regeneration, as well as sex, body condition, and season (dry or rainy) predict ectoparasite load. Our results indicate that investing energy and resources in tail regeneration compromises defence against ectoparasites. These costs differed between sexes and among species. Overall, ectoparasite load increases during the rainy season and is on average higher in males. In S. grammicus, during the rainy season, males with regenerated tails and in poor body condition had more ectoparasites than males with intact tails in good body condition. In S. megalepidurus, we observed the same effect during the rainy season but in females rather than males. In S. torquatus, we found no effect of tail loss on ectoparasite load. We discuss the possibility that differences observed among species reflect differences in both species-specific physiological trade-offs and local environmental conditions.

Many ecological attributes of organisms vary spatially. This strict dependency upon space generally arises by individuals occupying places with the necessary resources and conditions for survival. For lizards, losing the tail is an evolved mechanism that allows them to escape predators or to avoid aggressive intraspecific agonistic interactions. We evaluated the spatial relation of tail loss in a population of the lizard Tropidurus montanus. Our results support the occurrence of a spatial cluster of autotomized lizards. However, we cannot relate the cluster formation to the crowding of neighbouring lizards nor to individuals’ body size. Tail loss in lizards is known to be related to predatory attacks or intraspecific aggression, and we now show that tail autotomy occurs in a non-random way regarding space, and thus is also related to the space occupied by individuals in populations.

We aimed to analyze growth and longevity in relation to reproductive characteristics in a population of smallest species of agamid lizard, Phrynocephalus interscapularis using skeletochronology. Growth layers in the humerus were examined to estimate lizard age and growth, and to check the hypothesis of an annual turnover of short-term life of arid small lizards. Individual age of lizards in a sample of 50 individuals was determined. Ageing by skeletochronology showed the maximum age of lizards in the population as about three years and determined the following age structure of the sample: 18 one-year-old individuals (after the first hibernation), 19 two-year old individuals and 11 three-year old ones. It was shown that in studied population the largest specimen (a male of 37 mm) is not the oldest. The problem of ephemeral annual lizards is discussed.

Barisia imbricata imbricatais an endemic anguid lizard living in the highlands of central Mexico, mainly in the Trans-Mexican Volcanic Belt, but its current distribution is not well defined. For this reason, it is critical to make a systematic study in order to determine the potential distribution of this subspecies. We considered 13 environmental and anthropogenic variables recognized to be important to determine the presence ofB. i. imbricata; we also used eight presence-only modeling methods and selected three to generate an ensemble model. The Maxent algorithm was used to obtain the most important variables. The variables with highest contribution to the model were: maximum temperature of the warmest month, altitude,Abiesforest andPinusforest. From the estimated potential distribution (9614.1 km2), 8053.4 km2(83.8%) are located in the Trans-Mexican Volcanic Belt, 3821.4 km2(39.7%) are located in natural protected areas and 2418.2 km2(25.2%) are in crop fields. The whole potential distribution is highly fragmented and characterized by the presence of human activities, which could have long-term consequences, increasing extinction risk.

Improving the knowledge about the distribution of threatened species is a fundamental step forward for implementing effective measures for species conservation. Distribution maps of herpetological species are often inferred from morphological identification but, in some cases, morphology alone is not reliable for assessing the distribution of look-alike species. The common lizard Zootoca vivipara includes several lineages which, to date, cannot be distinguished by any conventional morphological traits. Therefore, a reliable taxonomic identification for the main Zootoca lineages is only feasible with genetic data. In this study, we identify a morphological trait that can be used to distinguish individuals of the parapatric Z. v. vivipara and Z. carniolica, without the support of molecular analyses. This method may provide a cost-effective tool to better depict the distribution of the threatened Z. carniolica and therefore prioritize the conservation of the locations where the oviparous Alpine lineage is found.

Predation risk influences decision making, escape behaviour, and resource use. Risk assessment and behavioural responses to predation can depend on demographic and environmental factors. We studied the escape behaviour of the long-nosed leopard lizard (Gambelia wislizenii) when approached by a human predator (= “simulated predator”), analysing flight initiation distance (FID) and flight distance (FD) relative to demographic and environmental variables. Starting distance (SD) of the simulated predator and orientation of prey lizards relative to the simulated predator influenced FID, but body size of the prey lizard did not. Sex interacted with SD to affect FID. Females lengthened their FIDs as SD increased, while male FID was unrelated to SD. Flight distance increased with increasing SD. Gambelia wislizenii’s ecological role as an ambush predator may explain their escape behaviour; reproductive status potentially affected the interaction between sex and SD.

Iridescence is a visual property of those surfaces that change in colour with viewing angle. Iridescence has been rarely reported in reptiles, but some snakes and lizards show this type of coloration. Here we study the effect of different angles of light incidence and observation on the spectrophotometrically assessed reflectance of dorsal coloration in the lizard Podarcis muralis. The results demonstrate clear angle dependence of several colour parameters. In particular, different angles of light incidence and observation result in changes in hue of more than 30 nm. This suggests that lizard dorsal coloration may be perceived, depending on viewing geometry, as being of different colours by a wide range of potential observers. Functional implications of iridescence in dorsal coloration are discussed.

We used video recordings of 29 pygmy bluetongue lizards for ten days of each month during their spring and summer activity season to observe scatting behaviour. This was possible because resident lizards rarely moved from their single entrance burrows. We used these observations to ask questions about social communication that might be relevant to conservation of this endangered species. We found lizards produced more scats in the middle of the day than earlier or later in the day, and more scats in the spring and early summer than later in the summer. Lizards moved an average of 68.54 ± 0.09 cm from their burrow entrance to deposit scats, taking an average of 2.4 min per defecation trip. They tended to use the same path direction for most defecation trips, but used more different directions if there were more close neighbours, strongly supporting a hypothesis that scats mark burrow ownership. The results suggested that conservation managers might reduce stress for relocated lizards by removing scat piles in the early stages of settlement.

Ameiva corax is restricted to a small island (Ameiva corax is known to socially feed at large food items such as seabird eggs. The individuals that can initially access these food items may occupy key roles in the social network.

Under a documented paleogeographic history of the Ria de Arosa archipelago, northwestern Spain, predictions can be made on the duration and strength of isolation ofPodarcis guadarramaelizard populations that were ‘captured’ on the islands when sea-levels rose. We predict that genetic diversity: i) is lower on islands than on the mainland, ii) increases with island size, and iii) decreases with increasing distance from the mainland. We also predict that the population genetic structure across islands and the mainland conforms to a pattern of isolation by distance (iv). To test these hypotheses, we analysed a panel of nine highly polymorphic microsatellite loci. The first (i) hypothesis was corroborated. We discuss our findings in the light of the effects of habitat fragmentation and lizard conservation.

The New Guinea scincid lizardEmoia ahli(Vogt, 1932), described from two specimens from the Sepik River in New Guinea, is shown to be indistinguishable fromEmoia battersbyi(Procter, 1923), a species from the same region, based on the first examination of the syntypes since the description of the species. Several of the diagnostic characters that have previously been invoked to distinguish the two species represent misinterpretations of statements in Vogt’s description.

The Caucasian rock lizard Darevskia mixta was sampled and studied from throughout its range, using mitochondrial cytochrome b sequences and scalation. The populations of the Greater and the Lesser Caucasus are reciprocally monophyletic matrilineally, and the respective lineages have been separated since the mid-Pleistocene. The lizards from the Greater Caucasus commonly have an unpaired preanal scale, whereas the lizards from the Lesser Caucasus have an additional scale behind the central temporal and subdivided interparietal scale more commonly than those from the Greater Caucasus. The Lesser Caucasus populations are further subdivided into two geographically distinct matrilineages, and are more diverse genetically and morphologically than the Greater Caucasus populations. The central part of the Lesser Caucasus is suggested to be the ancestral area for the entire D. mixta lineage. Successive Pleistocene periods of glaciation appear to be responsible both for the isolation of D. mixta from its common relatives, and for subdivision within D. mixta. Presence of D. mixta in NE Turkey is challenged.

Prey of different ages may exhibit differences in escape behavior, including flight initiation distance (FID – predator-prey distance when escape begins) and distance fled before stopping (DF). Escape theory predicts FID and, in some circumstance, DF, based on trade-offs between conflicting cost of not fleeing (predation risk) and cost of fleeing (primarily opportunities to enhance fitness lost by fleeing). The prey’s expected lifetime fitness when an encounter begins also affects escape decisions. Because hatchling and adult lizards may differ in ways that affect all three of these factors, a priori prediction of age differences is not possible without measurements of all three. In a field study I found that hatchling zebra-tailed lizards (Callisaurs draconoides) had much shorter FID and DF than adults. These relationships were not affected by distance to refuge, which did not differ between ages, and refuge use was infrequent. The findings agree with those of all but one previous study of age differences, suggesting that hatchling lizards typically have shorter FID and DF than adults because they 1) assess risk as being lower due to lower attractiveness to or detectability by predators, lack of experience or greater maneuverability, 2) have greater opportunity cost due to the need for rapid growth and good body condition before winter, and possibly 3) have lower residual reproductive value due to higher mortality rate than adults. Effects of age and size are confounded, and smaller size may be the major reason for the shorter FID and distance fled of hatchlings.

Different types of semi natural habitats has important role in long-term survival and maintenance of reptile species in urban environments. Heterogeneous urban green islands can provide conditions that enable competing species to live together in relatively small areas. However, the key mechanism of coexistence could vary from types of habitats and taxa. We investigated the population structure, the fine scale habitat segregation and diel activity pattern of two lizard species (Lacerta viridis and L. agilis) coexisting populations in a town cemetery. We hypothesized, that fine scale habitat segregation is a more important factor in coexistence than differences in diel activity pattern, because of the environmental dependent thermoregulation constrain. During the study, 178 L. agilis and 79 L. viridis occurrences were recorded. The daily activity patterns of both species were very similar, with peaks found in the forenoon and afternoon. Lizards were found to be the most active at 31-32°C. The probability of occurrence of the species was influenced more by the differences in the random selection of parcels rather than the random differences in the survey days. Around the proximate observation point the bush covered areas was significantly higher than average in the parcels. Our results showed that niche segregation based on fine scale habitat patches had a fundamental role in the coexistence of the two lizard species. L. agilis preferred the more open spaces, whereas L. viridis preferred areas with more bushes, but there was no difference in the daily activity pattern of the two species.

We describe a new species of whiptail lizard genus Ameivula from Planalto dos Gerais, a sandstone plateau that extends along the Cerrado region in the states of Bahia, Tocantins, Piauí, and Minas Gerais, in Brazil. The new species is the third recognized species of the A. ocellifera group registered for the Cerrado. Quantitative analyses of morphometric characters showed that Caatinga species are distinguished from their Cerrado congeners on basis of body size and shape. A discriminant analysis upon meristic characters showed that the new species can be clearly distinguished from the other two Cerrado species A. mumbuca and A. jalapensis, also the morphology of the finger lamellae, and clutch size distinguish these species.

Lizards and gulls cohabit in several Mediterranean islands. The yellow-legged gull, Larus michahellis, was found to prey several vertebrate species. However, precise information about the interaction between gulls and other vertebrates, particularly with lizards is still scarce. The Balearic lizard, Podarcis lilfordi, shares several coastal islets with the yellow-legged gull. Using two different sources of information, we studied the interaction of both species in Colom Island (Menorca, Balearic Islands, Spain). We studied the diet of the yellow-legged gull and learnt that the Balearic lizard is not a common prey of the yellow-legged gull. On the other hand, we studied the potential predation pressure of gulls on lizards, using plasticine models of lizards. We did two different experiments from which we can conclude that yellow-legged gulls rarely attack lizards and, consequently, cannot be considered a major threat for this endemic lizard species, at least in the population under study. Finally, we obtained evidence that plasticine models can only be employed with caution to assess predation pressure of opportunistic scavengers, much as gulls are. The majority of marks on models were not the consequence of true attacks by gulls, but the result of ground exploratory behaviour of gulls in search of any edible matter. Therefore, contrary to popular belief, in the case of the yellow-legged gull, the proportion of marked models would be an indication of ground-based wandering activity, rather than a result of its predation pressure on lizards.

Successful escape from predators may involve the use of multiple tactics. The wedge-snouted desert lizard (Meroles cuneirostris) flees from predators through a series of discrete moves with each move representing a specific manoeuvre type. By simulating the approach of a predator, we examined the role of sex and age (adult vs. juvenile) on the manoeuvre types used during escape, as well as the relationship between the number of moves needed to escape and the number of manoeuvre types employed. The eight defined manoeuvre types were used by all demographic groups, though there were differences among groups in the tendency to use certain manoeuvre types. In general, there was a strong difference in how adults and juveniles fled from predators. The number of manoeuvre types used by a lizard tended to increase with the number of moves required to escape and adults more readily added new manoeuvre types to an escape sequence. Demographic differences in escape behaviour might result from differing predation pressures incurred by juveniles and adults, and might also be related to the ontogeny of escape behaviour.

The Horn of Africa is a center of diversity for African agamid lizards. Among the nine species of Agama occurring in the Horn of Africa, Agama spinosa is the most widely distributed. The A. spinosa group (sensu stricto, morphologically defined by possessing six clusters of spinose scales around the ear) contains two species: A. spinosa occurs from Egypt to Ethiopia and Somalia where it is replaced by the morphologically distinct and therefore sensu lato A. bottegi. Both species are only represented in museum collections by a small number of specimens from Ethiopia and Somalia, presumably the result of constant civil war that has plagued the region for decades and impeded field surveys. In this study, we examine species limits in the A. spinosa group using molecular genetic data (503 characters; mitochondrial 16S rRNA) and morphological data (67 characters). Deep divisions among populations of A. spinosa are supported by phylogenetic analyses and by multivariate analyses of morphometric data. Two new species from northern Somalia that differ from A. spinosa and A. bottegi are described. Furthermore, A. smithi, currently recognized as a synonym of A. agama, is re-assessed and recognized as a species of uncertain taxonomic position (i.e., incertae sedis). The results of this study improve our understanding of the evolution of agamid lizard diversity in the Horn of Africa, a significant biodiversity hotspot in Africa.

Author version made available in accordance with the publisher's policy, Translocation is a powerful tool in conservation management, but one of the major problems of this tool is dispersal after release because of a tendency of animals to disperse from unfamiliar sites. We assessed whether short-term confinement within enclosures at the translocation site can significantly decrease post release movement, if confinement allowed animals to become familiar with the new habitat, and to overcome handling related stress. We simulated the translocation of the endangered pygmy bluetongue lizard Tiliqua adelaidensis into the centre of a large enclosure and compared the behaviour between individuals confined to the central region for one or five days before release. We found that lizards confined for five days spent less time basking, and were more likely to disperse than lizards confined for just one day. We suggest that short-term confinement of lizards induces additional stress and that extra days of short-term confinement will not necessarily improve the success of a translocation.

A new Colombian species of gymnophthalmid lizard is described from Porce River piedmont, in the northern region of the Cordillera Central of Colombia. The new species is allocated in the Anadia bitaeniata group and represents the westernmost member of the group. This species is distinguished primarily by the sub-hexagonal dorsal scales, large quadrangular ventral scales, ten femoral pores per leg not separated by inter-pore scales in both sexes, and by a combination of several characteristic scale counts, hemipenial morphology and color pattern. The threatened status of the new species is discussed.

The diet composition of rainbow lizards (Agama agama complex) populations was studied by feces analysis at eight distant places across a mega-transect in the Gulf of Guinea (West Africa), covering three countries: Togo, Benin and Nigeria. The effects of geography (= linear distance between study sites) and local conditions (using the mean annual rainfall as a proxy of the site-specific conditions) on dietary similarity of rainbow lizards were tested. Rainbow lizards were mainly insectivorous at all sites. Multivariate analyses identified four main groups of localities in terms of diet diversity indexes, with populations inhabiting forest towns tending to have less prey taxa richness than conspecifics from more arid areas, which instead had higher dietary evenness. Food niche overlap between populations was high among populations (range 0.631-0.940, ), and decreased with increases in the difference of mean annual rainfall between sites. There was no effect of the geographic distance on the similarity in diet composition between populations. A UPGMA dendrogram revealed a geographic trend in terms of presence/absence of the various prey types in the diets, with all the Nigerian study sites forming one cluster, whereas Lomé and Cotonou, two cities situated within the Dahomey Gap, being grouped apart. Overall, rainfall of the various sites seems to be more important than geographic distance for determining the taxonomic diet composition similarity of these lizards.

In many animals, aspects of colouration are hypothesized to convey information on the body condition or quality of individuals. This idea has been tested primarily for the carotenoid-based component of body colouration. The significance of other pigments in this context has received far less attention. In the common lizard, Zootoca vivipara, the degree of black patterning on the ventrum and throats is sexually dimorphic and varies considerably among individuals. In this study, we examine whether this melanin-based component of body colouration may reflect individual differences in quality (SVL, condition, immune response). We find that males (but not females) with a higher degree of ventral patterning mount a stronger phytohemagglutinin-induced immune response. The amount of black patterning does not correlate with body size, body condition, aspects of dorsal colouration or parasite load. We conclude that in male Zootoca vivipara, melanin-based ventral colouration may signal an aspect of immune capacity to sexual rivals or potential partners.

Maternal investment in the production of male versus female neonates was approximately equal in most animal species. However, sex allocation theory predicts that under certain conditions, selection may favor the females’ ability to adjust the sex ratio of their offspring, which females tend to use more for an investment of the rare sex. The mechanism of operational sex ratio (OSR) influence on sex allocation is still unclear, and recent studies conducted on lizards have reached conflicting conclusions. Here, we selected a viviparous lizard Eremias multiocellata to test whether pregnant females could adjust the sex ratio of their offspring in response to OSRs. Our results showed that mothers did not adjust the sex ratios or phenotypes of neonates in the laboratory and field-based experiments, except tail length. However, the OSRs subsequently affected growth in both mass and SVL of the offspring in laboratory experiments; whereas only the mass was affected in the semi-nature field experiments. Our results, thus, contradict the predictions of sex allocation theory and challenge the idea that female investment in the scarcity sex might serve as a mechanism which is used for adjusting the population sex ratio.

Comparative phylogeography describes the patterns of evolutionary divergence and whether or not they are congruent, in co-distributed populations of different taxa. If the populations of these taxa have been co-distributed for a prolonged time, and if the times between processes of perturbation or vicariance have been more or less stable, it is expected that patterns of divergence will be congruent in closely related species, for example because of similar biological and demographic characteristics.Liolaemus pictusandL. cyanogasterare widely co-distributed lizard species in southern Chile, occurring in a region with a complex topology. We analyzed the phylogeographic structure of the two lizard species usingCytochromebDNA sequences to estimate their genetic structure in response to historical events. Our results suggest an evolutionary pattern of genetic diversity for each species that is consistent with the geomorphological history of the region, suggesting a complex phylogeographic history inLiolaemusspecies. Also, the high levels of divergence among haplotypes in several populations suggest the possibility that their origin might predate the middle Pleistocene in both species. Finally, our results are consistent with our hypothesis that two species have responded to historical events in parallel, where historical process have been sufficient to influence their phylogeographical structure (0.80 congruency between topologies).