Lizard Diversity Research Articles

A new species of Gekko (Squamata: Gekkonidae) from central Luzon Island, Philippines

We describe a new species of gekkonid lizard, Gekko carusadensis, from low elevation, disturbed and secondary-growth forest in east-central Luzon Island, Philippines. Numerous features of its external morphology distinguish it from other congeners, including the presence of a distinct color pattern, body size, and a unique combination of scale counts. The new species has been found on karst outcrops and cave systems at low elevation. The new species typifies the rapidly expanding known diversity of Philippine gekkonid lizards, and is the third species in the genus to be described in the last three years.

Influence of coarse woody debris on herpetofaunal communities in upland pine stands of the southeastern Coastal Plain

Coarse woody debris (CWD) is thought to benefit herpetofauna in a variety of ways including serving as feeding sites, providing a moist environment, and providing protection from temperature extremes. We investigated the importance of CWD to amphibian and reptile communities in managed upland pine stands in the southeastern United States Coastal Plain during years 6 and 7 of a long-term study. Using a randomized complete block design, 1 of the following treatments was assigned to 9.3-ha plots: removal ( n = 3; all downed CWD ≥10 cm in diameter and ≥60 cm long removed), downed addition ( n = 3; five-fold increase in volume of down CWD), snag ( n = 3; 10-fold increase in volume of standing dead CWD), and control ( n = 3; unmanipulated). Herpetofauna were captured seasonally using drift-fence pitfall trapping arrays within treatment plots. We compared abundance, diversity, and richness of anurans, salamanders, lizards, and snakes using analysis of covariance with topographic variables (slope, elevation, aspect, and distance to nearest stream) included as covariates. We captured 355 amphibians and 668 reptiles seasonally from January 2007 to August 2008. Abundance, species richness, and species diversity were similar among treatments for anurans, salamanders, and lizards. Snake abundance, species richness, and diversity were higher in removal than downed addition plots. Anuran abundance increased as distance to nearest stream decreased. The majority of species captured during this study are adept at burrowing into the sandy soils of the region. Lack of reliance on CWD may be the result of herpetofaunal adaptation to the longleaf pine ( Pinus palustris) ecosystem that historically dominated the upland areas of the study area.

Tropical reptiles in pine forests: Assemblage responses to plantations and plantation management by burning

Worldwide, the land area devoted to timber plantations is expanding rapidly, especially in the tropics, where reptile diversity is high. The impacts of plantation forestry and its management on native species are poorly known, but are important, because plantation management goals often include protecting biodiversity. We examined the impact of pine ( Pinus caribaea ) plantations, and their management by fire, on the abundance and richness of reptiles, a significant proportion of the native biodiversity in tropical northern Australia, by (i) comparing abundance and diversity of reptiles among pine plantations (on land cleared specifically for plantation establishment), and two adjacent native forest types, eucalypt and Melaleuca woodlands, and (ii) comparing reptile abundance and richness in pine forest burnt one year prior to the study to remove understorey vegetation with pine forest burnt two years prior to the study. We also examined the influence of fire on reptile assemblages in native vegetation, by comparing eucalypt woodland burnt two years prior to the study and unburnt for eight years. To quantify mechanisms driving differences in reptile richness and abundance among forest types and management regimes, we measured forest structure, the temperatures used by reptiles (operative temperature) and solar radiation, at replicate sites in all forest types and management regimes. Compared to native forests, pine forests had taller trees, lower shrub cover in the understorey, more and deeper exotic litter (other than pine), and were cooler and shadier. Reptile assemblages in pine forests were as rich as those in native forests, but pine assemblages were composed mainly of species that typically use closed-canopy rainforest and prefer cooler, shadier habitats. Burning did not appear to influence the assemblage structure of reptiles in native forest, but burning under pine was associated with increased skink abundance and species richness. Burned pine was not warmer or sunnier than unburned pine, a common driver of reptile abundance, so the shift in lizard use after burning may have been driven by structural differences in understorey vegetation, especially amounts of non-native litter, which were reduced by burning. Thus, burning for management under pine increased the abundance and richness of lizard assemblages using pine. Pine plantations do not support the snake diversity common to sclerophyllous native forests, but pine may have the potential to complement rainforest lizard diversity if appropriately managed.

New Faces from Ancient Places: Uncovering Peninsular Malaysia’s Hidden Lizard Diversity Part II: Skinks

New Faces from Ancient Places: Uncovering Peninsular Malaysia’s Hidden Lizard Diversity Part II: Skinks

Effects of fire and cattle grazing on amphibians and lizards in northeastern Argentina (Humid Chaco)

Richness, diversity and abundance of amphibians and lizards were compared in four sites subjected to different fire and grazing regimes in Mburucuya National Park (Corrientes, Argentina). The surveys were performed using drift fence-pitfall traps randomly distributed in four sites subjected to the following prescribed fire and grazing regimes: (A) no fire or grazing for the last 12 years (control), (B) 3 years since the last prescribed fire, (C) annual prescribed fire and (D) annual prescribed fire and grazing. Fourteen species of amphibians and six species of lizards were captured during the study period (80 days). The lowest values of amphibian richness and abundance were found in sites C and D. The amphibian species Leptodactylus ocellatus and Leptodactylus podicipinus were most abundant in the control site (A). In lizards, no significant differences were found among sites, although Kentropyx viridistriga and Teius oculatus were more abundant in annually burnt sites (C and D). Vegetation variables were correlated with amphibian and lizard species composition. The species differed in their preference for the differently managed sites. The combination of fire and grazing had a negative effect on diversity of amphibians and lizards, with a greater effect on amphibians. Also, fire favoured the presence of some lizard species.

Long-term effects of a wildfire on a lizard assemblage in the Arid Chaco forest

The long-term (14 years) effects of a high-intensity wildfire on a lizard assemblage were studied in Chancaní Provincial Natural Park and Forest Natural Reserve (Córdoba, Argentina), by comparing a burned area with an unburned one within the protected area. Lizard diversity and abundance were measured using 25 drift-fence pitfall traps in the burned area and in a portion of the unburned forest during two summers (2006–2007 and 2007–2008). A total of 426 lizards belonging to eight species were captured. Total captures were 40% higher in the unburned area than in the burned one. From the eight species recorded, five ( Homonota fasciata, Leiosaurus paronae, Stenocercus doellojuradoi, Liolaemus chacoensis, and Teius teyou) were more abundant in the unburned area, whereas the remaining species ( Tropidurus etheridgei, Mabuya dorsivittata and Vanzosaura rubricauda) did not differ between areas. The differences observed in lizard numbers between sites may be related to fire-driven changes. A marked increase in grass cover determining the reduced availability of bare and litter-covered ground, fallen logs and dead wood, favorite microhabitats for most lizard species, is of particular significance.

New Faces from Ancient Places: Uncovering Peninsular Malaysia's Hidden Lizard Diversity

New Faces from Ancient Places: Uncovering Peninsular Malaysia's Hidden Lizard Diversity

A Taxonomic Account of Lizards Along Established Trails in Mts. Palay-Palay Mataas-Na-Gulod Protected Landscape, Luzon Island, Philippines

Twenty three species of lizards were recorded in Mts. PalaypalayMataas-Na-Gulod Protected Landscape. Belonging to four families; Agamidae is represented by three species, Gekkonidae with seven species, Scincidae with twelve species and Varanidae with one species. Fifty two percent of the species in Mts. Palaypalay-Mataas-Na-Gulod Protected Landscape is endemic which is dominated by forest species. Lizard diversity decreases with increase in elevation. Three major habitats (forest, stream and human habitation) were observed to be occupied by the species and habitat overlaps were observed as some species can occupy all habitat types.

Historical biogeography, phylogenetic relationships and intraspecific diversity of agamid lizards in the Central Asian deserts of Kazakhstan and Uzbekistan

The Central Asian agamid lizards are ecologically and morphologically diverse, occurring across a broad range of desert environments in this biogeographically important region. It is probable that past climatic shifts have significantly influenced the diversification patterns and distributions of the agamid lizards of this region. To assess this within a phylogenetic framework we sequenced a ∼1200 bp region of mitochondrial DNA and a ∼1200 bp nuclear gene (RAG-1), incorporating both inter- and intraspecific sampling across Central Asian agamids. Our topology and divergence time estimates support an Eocene origin of the Agaminae subfamily on the Indian subcontinent, coinciding with the collision of India into Eurasia. The onset of aridification in Central Asia during the Late Oligocene, resulting from the retreat of the Paratethys Sea and the intensified uplift of the Tibetan–Himalayan complex, probably played an important role in the diversification of Phrynocephalus, one of the three genera studied. Intensification of aridity and geologic events in the Plio-Pleistocene and Quaternary glacial cycling probably had a significant influence on intraspecific diversification patterns within Phrynocephalus.

Island area and species diversity in the southwest Pacific Ocean: is the lizard fauna of Vanuatu depauperate?

One island group suggested to be an exception to the species–area Relationship is the Vanuatu Archipelago, a group of 13 large and 80 small islands in the southwest Pacific Ocean. To test the hypothesis that the lizard fauna of the Vanuatu Archipelago does not meet the predictions of the species‐area relationship, and thus is depauperate, we compare diversity among several island groups in the southwest Pacific: Fiji, the Loyalty Islands, New Caledonia, Samoa, the Solomon Islands, Tonga, and Vanuatu. We found that the lizard diversity of Vanuatu meets the pattern of diversity predicted by the species‐area relationship. The Solomon Islands, the largest and least isolated oceanic archipelago considered, has the greatest species diversity and endemism of the oceanic islands. Inclusion or exclusion of island groups based on factors such as geologic history or faunal source affects the strength of the relationship between diversity, area, and history of emergence, and influences perceptions of diversity within individual archipelagos. In addition to island size, factors such evolutionary time scale, speciation, and archipelago complexity influence species richness on islands.

What determines dewlap diversity in Anolis lizards? An among‐island comparison

Animal signalling systems are extremely diverse as they are under different, often conflicting, selective pressures. A classic textbook example of a diverse signal is the anoline dewlap. Both at the inter- and intraspecific levels, dewlap size, colour, shape and pattern vary extensively. Here, we attempt to elucidate the various factors explaining the diversity in dewlap size and pattern among seven Anolis sagrei populations from different islands in the Bahamas. The seven islands differ in the surface area, number and kind of predators, sexual size dimorphism and Anolis species composition. In addition, we investigate whether selective pressures acting on dewlap design differ between males and females. Whereas dewlap pattern appears to serve a role in species recognition in both sexes, our data suggest that relative dewlap size is under natural and/or sexual selection. We find evidence for the role of the dewlap as a pursuit-deterrence signal in both males and females as relative dewlap size is larger on islands where A. sagrei occurs sympatrically with predatory Leiocephalus lizards. Additionally, in males relatively large dewlaps seem to be selected for in a sexual context, whereas in females natural selection, for instance by other predators than Leiocephalus lizards, appears to constrain relative dewlap size.

Refining the polytypic species concept of mangrove monitors (Squamata: Varanus indicus group): a new cryptic species from the Talaud Islands, Indonesia, reveals the underestimated diversity of Indo-Australian monitor lizards

The description of a new cryptic member of the mangrove monitor (Varanus indicus) (Daudin, 1802) group from Indonesia presents a refinement of the systematic concept for a polytypic complex of closely related species. The new species is recognised on the basis of morphological and molecular evidence. It is so far known only from the type locality, the remote Talaud Islands, located between Sulawesi, Halmahera and Mindanao at the outer boundary of the Wallacea transition zone between the Oriental and Australian faunal regions. While the descriptions of several sibling and mostly sympatric species within the last 15 years have not affected the range of V. indicus, here, we demonstrate that morphologically distinct island populations represent independent evolutionary lineages and warrant specific recognition as distinct species within an evolving superspecies complex. In addition, some basic natural history information is provided for the new species based on observations at the type locality. These systematic and zoogeographic investigations reveal shortcomings in the current knowledge concerning the diversity and endemism of Indo-Australian monitor lizards, particularly within the Wallacean region.

Effects of Conversion of Dry Tropical Forest to Agricultural Mosaic on Herpetofaunal Assemblages

We explored the impact of forest conversion to agricultural mosaic on anuran, lizard, snake, and turtle assemblages of Neotropical dry forests. Over 2 years, we sampled 6 small watersheds on the west coast of Mexico, 3 conserved and 3 disturbed. The disturbed watersheds were characterized by a mosaic of pastures and cultivated fields (corn, beans, squash) intermingled with patches of different successional stages of dry forest. In each watershed, we conducted 11 diurnal and nocturnal time-constrained searches in 10 randomly established plots. We considered vulnerability traits of species in relation to habitat modification. Eighteen anuran, 18 lizard, 23 snake, and 3 turtle species were recorded. Thirty-six species (58%) occurred in both forest conditions, and 14 (22%) and 12 species (19%) occurred only in the conserved and disturbed sites, respectively. Assemblages responded differently to disturbance. Species richness, diversity, and abundance of lizards were higher in disturbed forests. Anuran diversity and species richness were lower in disturbed forest but abundance was similar in both forest conditions. Diversity, richness, and abundance of turtles were lower in disturbed forest. The structure and composition of snake assemblages did not differ between forest conditions. We considered species disturbance sensitive if their abundance was significantly less in disturbed areas. Four anuran (22%), 2 lizard (11%), and 3 turtle (100%) species were sensitive to disturbance. No snake species was sensitive. The decline in abundance of disturbance-sensitive species was associated with the reduction of forest canopy cover, woody stem cover, roots, and litter-layer ground cover. Anuran species with small body size and direct embryonic development were especially sensitive to forest disturbance. An important goal for the conservation of herpetofauna should be the determination of species traits associated with extinction or persistence in agricultural mosaics.

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.

Global diversity of lizards in freshwater (Reptilia: Lacertilia)

No lizards are strictly aquatic, but at least 73 species in 11 different families can be considered to regularly utilize freshwater habitats. There are no aquatic lizards in the Nearctic or Palearctic regions, whereas the Neotropics, Southeast Asia, and the Indo-Australian Archipelago support the greatest diversity of freshwater forms, particularly in the families Gymnophthalmidae, Scincidae and Varanidae. A number of larger aquatic lizards are harvested for food and for the reptile skin trade and several are CITES listed.

Nuclear and mtDNA-based phylogeny of southern African sand lizards, Pedioplanis (Sauria: Lacertidae)

The diversity of lacertid lizards in Africa is highest in the southern African subcontinent, where over two-thirds of the species are endemic. With eleven currently recognized species, Pedioplanis is the most diverse among the southern African genera. In this study we use 2200 nucleotide positions derived from two mitochondrial markers (ND2 and 16S rRNA) and one nuclear gene (RAG-1) to (i) assess the phylogeny of Pedioplanis and (ii) estimate divergence time among lineages using the relaxed molecular clock method. Individual analyses of each gene separately supported different nodes in the phylogeny and the combined analysis yielded more well supported relationships. We present the first, well-resolved gene tree for the genus Pedioplanis and this is largely congruent with a phylogeny derived from morphology. Contrary to previous suggestions Heliobolus/ Nucras are sister to Pedioplanis. The genus Pedioplanis is monophyletic, with P. burchelli/ P. laticeps forming a clade that is sister to all the remaining congeners. Two distinct geographic lineages can be identified within the widespread P. namaquensis; one occurs in Namibia, while the other occurs in South Africa. The P. undata species complex is monophyletic, but one of its constituent species, P. inornata, is paraphyletic. Relationships among the subspecies of P. lineoocellata are much more complex than previously documented. An isolated population previously assigned to P. l. pulchella is paraphyletic and sister to the three named subspecies. The phylogeny identifies two biogeographical clades that probably diverged during the mid-Miocene, after the development of the Benguella Current. This probably led to habitat changes associated with climate and, in conjunction with physical barriers (Great Escarpment), contributed towards speciation within the genus Pedioplanis.

Microhabitat use, diet, and performance data on the Hispaniolan twig anole, Anolis sheplani: Pushing the boundaries of morphospace

Caribbean Anolis lizards are often cited as a textbook example of adaptive radiation. Similar morphologies (ecomorphs) have originated in similar ecological settings on different large islands in the West Indies. However, relatively little is known about one of the morphologically most specialized and divergent ecomorphs: the twig anoles. Here, we investigate aspects of morphology, dewlap size, locomotor and bite performance, structural habitat and diet of the poorly known twig anole, Anolis sheplani from Hispaniola. Few observations have previously been made of this species in its natural habitat, and few quantitative data on its natural history are available. A. sheplani is an extreme twig anole with respect to its morphology, performance capacities, and ecological niche. Males and females of this species do not differ from each other in body dimensions, performance or habitat use, but males do have a bigger dewlap than females. We present data for 25 individuals and compare them with data for other Greater Antillean anoles. It becomes apparent that twig anoles constitute a large component of the morphological, functional, and ecological diversity of Anolis lizards. Small twig anoles such as A. sheplani appear to be pushing the boundaries of morphospace and are thus crucial in our understanding of the evolution of phenotypic diversity.

Tracing the origins of signal diversity in anole lizards: phylogenetic approaches to inferring the evolution of complex behaviour

Within species, natural and sexual selection work together to shape the design of animal communicative systems, and sometimes act differentially on alternate components to produce a single elaborate phenotype that works well in several contexts. Here, we show a similar pattern at the interspecific level, and describe how an intricate selective regime can shape diversification of a complex behaviour across species. Using four phylogenetic comparative methods, alternative phylogenetic hypotheses, and a data set compiled from over 50 different sources representing 53 taxa, we test the relative importance of different ecological variables on the evolution of anole visual displays. Our study makes use of the inherent complexity of these signals and the availability of published descriptions in the form of display-action-patterns. Results indicate that different selective forces are linked to change in different display components. Whereas evolutionary changes in display duration appear to be linked to sexual size dimorphism, measures of display complexity (number and uniformity of display components) were more tightly associated with the need to facilitate species recognition and the type of light environment in which the display is typically performed. We also found some evidence that ecomorph distinctions, a major force in morphological evolution of anoles, have had an impact on the evolution of display structure. We use our findings to highlight areas for future research and discuss the similarities and differences between display evolution in anoles and in other lizard genera.

Habitat variation and lizard diversity in a Cerrado area of Central Brazil

Lizard richness, composition and local distribution were studied in a 6000 ha preserved tract of Cerrado in central Brazil. Recorded richness, with 17 species in seven families, is higher than most presented for Cerrado localities. The lizard assemblage is significantly structured in terms of local distribution, being dominated by species with strict and predictable habitat requirements, following the mosaic of available habitats. A large portion of the species recorded is exclusive to open, interfluvial habitats. Faunal overlap between gallery forests and open habitats was extremely restricted. Previous interpretations describing the Cerrado lizard fauna as depauperate and similar to the fauna of other open Neotropical domains were not corroborated. Instead, our results corroborate recent interpretations pointing out horizontal stratification and habitat patchyness as strong factors influencing the rich, complex and characteristic Cerrado lizard fauna.

Out of Cuba: overwater dispersal and speciation among lizards in theAnolis carolinensissubgroup

Overwater dispersal and subsequent allopatric speciation contribute importantly to the species diversity of West Indian Anolis lizards and many other island radiations. Here we use molecular phylogenetic analyses to assess the contribution of overwater dispersal to diversification of the Anolis carolinensis subgroup, a clade comprising nine canopy-dwelling species distributed across the northern Caribbean. Although this clade includes some of the most successful dispersers and colonists in the anole radiation, the taxonomic status and origin of many endemic populations have been ambiguous. New mitochondrial and nuclear DNA sequences from four species occurring on small islands or island banks (Anolis brunneus, Anolis longiceps, Anolis maynardi, Anolis smaragdinus) and one species from the continental United States (A. carolinensis) are presented and analysed with homologous sequences sampled from related species on Cuba (Anolis allisoni and Anolis porcatus). Our analyses confirm that all five non-Cuban species included in our study represent distinct, independently evolving lineages that warrant continued species recognition. Moreover, our results support Ernest Williams's hypothesis that all of these species originated by overseas colonization from Cuban source populations. However, contrary to Williams's hypothesis of Pleistocene dispersal, most colonization events leading to speciation apparently occurred earlier, in the late Miocene-Pliocene. These patterns suggest that overwater dispersal among geologically distinct islands and island banks is relatively infrequent in anoles and has contributed to allopatric speciation. Finally, our results suggest that large Greater Antillean islands serve as centres of origin for regional species diversity.