Trophic ecology of Gymnodactylus geckoides Spix, 1825 (Squamata, Phyllodactylidae) from Caatinga, Northeastern Brazil

The diet of lizards is mainly composed of arthropods. It can be affected by biotic and abiotic factors, which influence the energy supply provided by the composition of the animal´s diet. The richness and abundance of many arthropod species can be influenced by environmental seasonality, especially in the Caatinga ecoregion, due to the rainfall regimes. The present study aims to describe aspects of the seasonal and morphological variation in the lizard Gymnodactylus geckoides diet and their energy content. We collected 157 individuals (63 females, 68 males, and 26 juveniles) at the Catimbau National Park, Northeastern Brazil, of which 72 were analyzed for the dry season and 59 for the rainy season. Our data indicates Isoptera to be the most common prey in G. geckoides’s diet. Energy content, prey number was higher in the dry season, whereas prey volume and glycogen content increased in the rainy season. Proteins and lipids did not show marked differences. The present study represents the first effort to understand variations in G. geckoide’s trophic ecology, indicating that this specie presents a wide variation in their diet, especially when considering seasonal factors, revealing their needs and restrictions according to prey availability and environmental conditions.

The ecology of sleep in non-avian reptiles

Sleep is ubiquitous in the animal kingdom and yet displays considerable variation in its extent and form in the wild. Ecological factors, such as predation, competition, and microclimate, therefore are likely to play a strong role in shaping characteristics of sleep. Despite the potential for ecological factors to influence various aspects of sleep, the ecological context of sleep in non-avian reptiles remains understudied and without systematic direction. In this review, we examine multiple aspects of reptilian sleep, including (i) habitat selection (sleep sites and their spatio-temporal distribution), (ii) individual-level traits, such as behaviour (sleep postures), morphology (limb morphometrics and body colour), and physiology (sleep architecture), as well as (iii) inter-individual interactions (intra- and inter-specific). Throughout, we discuss the evidence of predation, competition, and thermoregulation in influencing sleep traits and the possible evolutionary consequences of these sleep traits for reptile sociality, morphological specialisation, and habitat partitioning. We also review the ways in which sleep ecology interacts with urbanisation, biological invasions, and climate change. Overall, we not only provide a systematic evaluation of the conceptual and taxonomic biases in the existing literature on reptilian sleep, but also use this opportunity to organise the various ecological hypotheses for sleep characteristics. By highlighting the gaps and providing a prospectus of research directions, our review sets the stage for understanding sleep ecology in the natural world.

Helminth fauna of Norops fuscoauratus (D'Orbigny, 1837) (Squamata: Dactyloidae) in the Atlantic Forest, northeastern Brazil

The composition of macro endoparasites associated with the lizard Norops fuscoauratus (Squamata) was analysed in two localities in the Atlantic Forest on the northeast of Brazil between December 2012 and July 2015. 74 specimens of N. fuscoauratus were examined and five species of helminths were reported, being: (a) for the population of Pernambuco: Cystacanth (Prevalence=37.5%), Physaloptera retusa Rudolphi, 1819 (Prevalence=4.16%), larva of flatworm (Prevalence=2.08%), Rhabdias sp. (Prevalence=2.08%) and Strongyluris oscari Travassos, 1923 (Prevalence=2.08%), and (b) of Alagoas: S. oscari (Prevalence=17.85%) and Rhabdias sp. (Prevalence=3.57%). The differences in the composition of endoparasites in the two populations are attributed to individualities of environments occupied by the lizards. The collection period does not influence the abundance of parasites, but when associated with sex, there was a positive correlation with the abundance of helminths, with more females than males being infected with parasites in the rainy season.

Convergent patterns of adaptive radiation between island and mainland Anolis lizards

Uncovering convergent and divergent patterns of diversification is a major goal of evolutionary biology. On four Greater Antillean islands, Anolis lizards have convergently evolved sets of species with similar ecologies and morphologies (ecomorphs). However, it is unclear whether closely related anoles from Central and South America exhibit similar patterns of diversification. We generated an extensive morphological data set to test whether mainland Draconura-clade anoles are assignable to the Caribbean ecomorphs. Based on a new classification framework that accounts for different degrees of morphological support, we found morphological evidence for mainland representatives of all six Caribbean ecomorphs and evidence that many ecomorphs have also evolved repeatedly on the mainland. We also found strong evidence that ground-dwelling anoles from both the Caribbean and the mainland constitute a new and distinct ecomorph class. Beyond the ecomorph concept, we show that the island and mainland anole faunas exhibit exceptional morphological convergence, suggesting that they are more similar than previously understood. However, the island and mainland radiations are not identical, indicating that regional differences and historical contingencies can lead to replicate yet variable radiations. More broadly, our findings suggest that replicated radiations occur beyond island settings more often than previously recognized.

Evolutionary drivers of sexual signal variation in Amazon Slender Anoles

Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species' range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the dewlap colors of Amazon Slender Anoles, Anolis fuscoauratus. To this aim, we characterized dewlap diversity in the field with respect to population genetic structure and evolutionary relationships, assessed whether dewlap phenotypes are associated with climate or landscape variables, and tested for nonrandom associations in the distributions of A. fuscoauratus phenotypes and sympatric Anolis species. We found that dewlap colors vary among but not within sites in A. fuscoauratus. Regional genetic clusters included multiple phenotypes, while populations with similar dewlaps were often distantly related. Phenotypes did not segregate in environmental space, providing no support for optimized signal transmission at a local scale. Instead, we found a negative association between certain phenotypes and sympatric Anolis species with similar dewlap color attributes, suggesting that interactions with closely related species promoted dewlap divergence among A. fuscoauratus populations. Amazon Slender Anoles emerge as a promising system to address questions about parallel trait evolution and the contribution of signaling traits to speciation.

Helminths associated with Norops fuscoauratus (Squamata, Dactyloidae) in highland marshes of the Brazilian semi-arid

Helminthological studies may contribute with valuable information on host biology and conservation. Herein, we provide new data on helminths infecting the lizard Norops fuscoauratus, testing one of the factors considered most important in parasitic ecology: host size. We analysed 25 specimens of N. fuscoauratus from three highland marshes in the Brazilian semi-arid. Eight taxa of helminths belonging to Nematoda, Trematoda and Acanthocephala were found. Physaloptera sp. showed the higher prevalence (40%), with a mean intensity of infection of 3.3 ± 1.46 (1-16) and mean abundance 1.32 ± 0.65 (0-16). Norops fuscoauratus represents four new host records for the helminths Cyrtosomum sp., Pharyngodon travassosi, Strongyloides sp. and Centrorhynchus sp. There is no relationship of host body size (P = 0.79) and mass (P = 0.50) with parasite richness. In addition, the present study contributes to the knowledge of the parasitic fauna of N. fuscoauratus and the Neotropical region.

Evolution of ecological structure of anole communities in tropical rain forests from north-western South America

The coexistence of several anoles in the same place is attributed to differential partitioning of resources. Although several mainland and island communities show a similar structure, differences in life-history traits, absence of niche complementarity, higher food supply and higher numbers of predators in mainland environments support the idea that predation, rather than competition, is a more important structuring force in mainland than in island anole communities. To analyse the pattern of ecological structure in mainland anole communities, we studied communities in three tropical rain forests of north-western South America to obtain data about the use of resources on three niche axes [spatial, thermal and morphological (as a proxy of diet)] for 17 species of anoles. We analysed the patterns of niche overlap for each axis and found that overlap on the dietary axis was less than the overlap on the other axes, indicating that species using similar spatial or thermal resources diverge strongly in their diet. In addition, we identified a niche complementarity among niche axes, suggesting that intraspecific competition is also an important process in those communities. Finally, this study revealed a similar ecological structure in different communities of mainland rain-forest anoles, which share seven ecomorphs, suggesting ecological adaptation and convergence in mainland anoles.

Local adaptation in mainland anole lizards: Integrating population history and genome-environment associations

Environmental gradients constrain physiological performance and thus species' ranges, suggesting that species occurrence in diverse environments may be associated with local adaptation. Genome-environment association analyses (GEAA) have become central for studies of local adaptation, yet they are sensitive to the spatial orientation of historical range expansions relative to landscape gradients. To test whether potentially adaptive genotypes occur in varied climates in wide-ranged species, we implemented GEAA on the basis of genomewide data from the anole lizards Anolis ortonii and Anolis punctatus, which expanded from Amazonia, presently dominated by warm and wet settings, into the cooler and less rainy Atlantic Forest. To examine whether local adaptation has been constrained by population structure and history, we estimated effective population sizes, divergence times, and gene flow under a coalescent framework. In both species, divergence between Amazonian and Atlantic Forest populations dates back to the mid-Pleistocene, with subsequent gene flow. We recovered eleven candidate genes involved with metabolism, immunity, development, and cell signaling in A. punctatus and found no loci whose frequency is associated with environmental gradients in A. ortonii. Distinct signatures of adaptation between these species are not associated with historical constraints or distinct climatic space occupancies. Similar patterns of spatial structure between selected and neutral SNPs along the climatic gradient, as supported by patterns of genetic clustering in A. punctatus, may have led to conservative GEAA performance. This study illustrates how tests of local adaptation can benefit from knowledge about species histories to support hypothesis formulation, sampling design, and landscape gradient characterization.

Thermal physiology of Amazonian lizards (Reptilia: Squamata)

We summarize thermal-biology data of 69 species of Amazonian lizards, including mode of thermoregulation and field-active body temperatures (Tb). We also provide new data on preferred temperatures (Tpref), voluntary and thermal-tolerance ranges, and thermal-performance curves (TPC's) for 27 species from nine sites in the Brazilian Amazonia. We tested for phylogenetic signal and pairwise correlations among thermal traits. We found that species generally categorized as thermoregulators have the highest mean values for all thermal traits, and broader ranges for Tb, critical thermal maximum (CTmax) and optimal (Topt) temperatures. Species generally categorized as thermoconformers have large ranges for Tpref, critical thermal minimum (CTmin), and minimum voluntary (VTmin) temperatures for performance. Despite these differences, our results show that all thermal characteristics overlap between both groups and suggest that Amazonian lizards do not fit into discrete thermoregulatory categories. The traits are all correlated, with the exceptions of (1) Topt, which does not correlate with CTmax, and (2) CTmin, and correlates only with Topt. Weak phylogenetic signals for Tb, Tpref and VTmin indicate that these characters may be shaped by local environmental conditions and influenced by phylogeny. We found that open-habitat species perform well under present environmental conditions, without experiencing detectable thermal stress from high environmental temperatures induced in lab experiments. For forest-dwelling lizards, we expect warming trends in Amazonia to induce thermal stress, as temperatures surpass the thermal tolerances for these species.

Dietary niche variation and its relationship to lizard population density

Insular species are predicted to broaden their niches, in response to having fewer competitors. They can thus exploit a greater proportion of the resource spectrum. In turn, broader niches are hypothesized to facilitate (or be a consequence of) increased population densities. We tested whether insular lizards have broader dietary niches than mainland species, how it relates to competitor and predator richness, and the nature of the relationship between population density and dietary niche breadth. We collected population density and dietary niche breadth data for 36 insular and 59 mainland lizard species, and estimated competitor and predator richness at the localities where diet data were collected. We estimated dietary niche shift by comparing island species to their mainland relatives. We controlled for phylogenetic relatedness, body mass and the size of the plots over which densities were estimated. We found that island and mainland species had similar niche breadths. Dietary niche breadth was unrelated to competitor and predator richness, on both islands and the mainland. Population density was unrelated to dietary niche breadth across island and mainland populations. Our results indicate that dietary generalism is not an effective way of increasing population density nor is it result of lower competitive pressure. A lower variety of resources on islands may prevent insular animals from increasing their niche breadths even in the face of few competitors.

Anolis lizards as biocontrol agents in mainland and island agroecosystems

Our knowledge of ecological interactions that bolster ecosystem function and productivity has broad applications to the management of agricultural systems. Studies suggest that the presence of generalist predators in agricultural landscapes leads to a decrease in the abundance of herbivorous pests, but our understanding of how these interactions vary across taxa and along gradients of management intensity and eco‐geographic space remains incomplete. In this study, we assessed the functional response and biocontrol potential of a highly ubiquitous insectivore (lizards in the genus Anolis) on the world's most important coffee pest, the coffee berry borer (Hypothalemus hampei). We conducted field surveys and laboratory experiments to examine the impact of land‐use intensification on species richness and abundance of anoles and the capacity of anoles to reduce berry borer infestations in mainland and island coffee systems. Our results show that anoles significantly reduce coffee infestation rates in laboratory settings (Mexico, p = .03, F = 5.13 df = 1, 35; Puerto Rico, p = .014, F = 8.82, df = 1, 10) and are capable of consuming coffee berry borers in high abundance. Additionally, diversified agroecosystems bolster anole abundance, while high‐intensity practices, including the reduction of vegetation complexity and the application of agrochemicals were associated with reduced anole abundance. The results of this study provide supporting evidence of the positive impact of generalist predators on the control of crop pests in agricultural landscapes, and the role of diversified agroecosystems in sustaining both functionally diverse communities and crop production in tropical agroecosystems.

Helminths of lizards from the municipality of Aripuanã in the southern Amazon region of Brazil

Ninety-five specimens from 13 species of lizard collected during a herpetofaunal monitoring programme of the Faxinal II power plant, municipality of Aripuanã, state of Mato Grosso, Brazil (southern Amazon region) were examined for helminths. A total of 21 helminth species (16 Nematoda, 1 Cestoda and 4 Trematoda) were recovered, with an overall prevalence of 67.37%. Seventeen new host records and seven new locality records are reported. A low number of specialists and core helminth species were found. Lizard body size was positively correlated with both the total number of helminth species and individuals. Active foragers exhibited higher helminth diversity. However, sit-and-wait foragers, especially Plica plica, had similar diversity values as active foragers and harboured more helminth species. The degree of similarity in helminth fauna was higher among closely related host species.

Lagartos (Squamata: Lacertilia) em áreas de floresta e de pastagem em Espigão do Oeste, Rondônia, sudoeste da Amazônia, Brasil

O presente estudo apresenta dados sobre riqueza e freqüência de captura de lagartos em áreas de floresta e pastagem em uma localidade em Rondônia (sudoeste da Amazônia) utilizando três métodos de amostragem: armadilhas de interceptação e queda, procura noturna limitada por tempo (encontro de espécimes dormindo sobre a vegetação) e encontros ocasionais. Foram encontradas 29 espécies distribuídas em nove famílias. A maioria das espécies (28) foi encontrada em floresta, enquanto que na pastagem foram encontradas oito. A maioria das espécies foi registrada pelas armadilhas de interceptação e queda (22), seguido pelos encontros ocasionais (16) e procura noturna (9). A curva do coletor apresentando dados de todos os métodos mostra que a partir do oitavo mês de amostragem não houve mais nenhum acréscimo de nova espécie nessa comunidade, evidenciando que a mesma foi bem amostrada. O fato de algumas espécies terem sido coletadas exclusivamente em apenas um dos métodos, demonstra a importância de se usar dois ou mais métodos de amostragem em estudos sobre comunidades. Essa redução de espécies se deve a retirada da cobertura vegetal e, possivelmente, às suas conseqüências: aumento das taxa de predação e de competição, dificuldades para a termo-regulação, perda de locais para abrigos e reprodução, diminuição dos recursos alimentares e perda de serapilheira.

Can lizard richness be driven by termite diversity? Insights from the Brazilian Cerrado

We test predictions of the Morton and James hypothesis, which states that high termite diversity promotes high lizard diversity. We explore consumption of termites by lizards in the Brazilian Cerrado, a system that shares many similarites with arid Australia whose fauna formed the basis for the original hypothesis. We found that Cerrado lizards prey heavily on termites. Several species had >40% of their diet consisting of termites, some species reached up to 80%. However, lizards prey on termites independently of their diversity in the environment and do not show niche segregation in relation to termite resource. Hence, our results in the Cerrado do not support the hypothesis that termite diversity can promote lizard diversity. The diets of Cerrado lizards have a high proportion of termites; however, the diets of desert lizards from the Australian and the Kalahari deserts have a much higher proportion of termites when compared with those from the Cerrado and the Amazon. Differences in termite consumption by lizards across ecosystems do not seem to be related to local termite diversity. We hypothesize that overall prey availability can explain this pattern. Several arthropod groups are abundant in the Cerrado and the Amazon. In deserts, other prey types may be less abundant; therefore, termites may be the best available resource.

Molecular phylogenetics of the Anolis onca series: a case history in retrograde evolution revisited

Anoles of the Anolis onca series represent a dramatic case of retrograde evolution, exhibiting great reduction (A. annectens) and loss (A. onca) of the subdigital pads considered a key innovation for the evolutionary radiation of anoles in arboreal environments. We present a molecular phylogenetic analysis of these anoles and their closest known relatives (A. auratus, A. lineatus, A. meridionalis, and A. nitens) using new mitochondrial DNA sequence data from the ND2 gene, five tRNA genes (tRNA(Trp), tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr)), the origin of light-strand replication, and a portion of the CO1 gene (1,446 aligned base positions, 612 parsimony informative). Our results confirm monophyly of the A. onca series and suggest an evolutionary separation of approximately 10 million years between A. annectens and A. onca. Evolution of subdigital structure in this series illustrates ectopic expression of developmental programs that replace flexible subdigital lamellae of the toepad with rigid, keeled scales resembling dorsal digital scales. Our phylogenetic results indicate that narrowing of the toepad in A. auratus evolved separately from toepad reduction in the A. onca series. Expansion of the subdigital lamellae along the phalanges in A. auratus appears to compensate constriction of lamellae by digital narrowing, maintaining greater climbing capability in this species. Toepad evolution in the lineage ancestral to A. auratus features changes of the same developmental modules as the A. onca series but in the opposite direction. Large molecular distances between geographic populations of A. auratus indicate that its derived toepad structure is at least 9 million years old.