Find research datasets worth reusing

opencc-by-4.0Jan 2020View details →

Dataset Mother-offspring conflict for water varies across altitude and is mitigated in the oviparous form of the bimodal lizard Zootoca vivipara

The female dataset provides the responses of gravid and non reproductive female common lizard to a two week period of water restriction. This includes the measures of body mass (BM) and plasma osmolality (osmo) at the onset and the end of this timing. Dataset also reports different information on reproductive performance and characteristics of the population they came from.  The juvenile dataset provides the morphological (snout-vent length: SVL, body mass: BM) and the sex of hatchling. We also included information about mother identity (cltuch effect), mother treatment and the characteristics of populations they came from.

opencc-zeroJun 2020View details →

A morphometric assessment of species boundaries in a widespread anole lizard (Squamata: Dactyloidae)

Cryptic species - genetically distinct species that are morphologically difficult to distinguish - present challenges to systematists. Operationally, cryptic species are very difficult to identify and sole usage of genetic data or morphological data can fail to recognize evolutionarily isolated lineages. We use morphometric data to test species boundaries hypothesized with genetic data in the North Caribbean Bark Anole (Anolis distichus), a suspected species complex. We use univariate and multivariate analyses to test if candidate species based on genetic data can be accurately diagnosed. We also test alternate species delimitation scenarios with a model fitting approach that evaluates normal mixture models capable of identifying morphological clusters. Our analyses reject the hypothesis that the candidate species are diagnosable. Neither uni- nor multivariate morphometric data distinguish candidate species. The best supported model included two morphological clusters; however, these clusters were uneven and did not align with a plausible species divergence scenario. After removing two related traits driving this result, only one cluster was supported. Despite substantial differentiation revealed by genetic data, we recover no new evidence to delimit species and refrain from taxonomic revision. This study highlights the importance of considering other types of data along with molecular data when delimiting species.

opencc-zeroAug 2020View details →

Data from: Thinking outside the box: problem-solving in free-living lizards

Despite evidence that organisms are more likely to exhibit their full range of cognitive abilities under conditions found in nature, studies evaluating cognition under such conditions remain rare, particularly in vertebrate species. Here we conducted an experiment to evaluate problem solving and motor-self regulation in free-living arboreal lizards, Anolis sagrei, under natural conditions. We presented lizards with a novel detour problem which challenged individuals to circumvent a transparent barrier in order to obtain a food reward. Individuals varied in their ability to solve the detour problem. Furthermore, those that solved the problem were able to improve their performance across trials by modifying the natural response of attempting to strike the reward trough the transparent barrier, providing evidence of motor self-regulation. Solving the problem required individuals to modify their typical foraging behavior, as approaching the prey in a single burst of movement that culminated with an attack was an unsuccessful strategy. Contrary to expectations our findings provide evidence of motor self-regulation in a visually-oriented, sit-and-wait predator under natural conditions, suggesting motor-self-regulation is not limited by foraging strategy. Our results also underscore the need to evaluate the cognitive abilities of free-living organisms in the wild, particularly for taxa that perform poorly under laboratory conditions.

opencc-zeroAug 2020View details →

Character displacement in the midst of background evolution in island populations of Anolis lizards: a spatiotemporal perspective

Negative interactions between species can generate divergent selection that causes character displacement. However, other processes cause similar divergence. We use spatial and temporal replication of island populations of Anolis lizards to assess the importance of negative interactions in driving trait shifts. Previous work showed that the establishment of Anolis sagrei drove resident Anolis carolinensis to perch higher and evolve larger toepads. To further test the interaction's causality and predictability, we resurveyed a subset of islands nine years later. Anolis sagrei had established on one island between surveys. We found that A. carolinensis on this island now perch higher and have larger toepads. However, toepad morphology change on this island was not distinct from shifts on six other islands whose Anolis community composition had not changed. Thus, the presence of A. sagrei only partly explains A. carolinensis trait variation across space and time. We also find that A. carolinensis on islands with previously established A. sagrei now perch higher than a decade ago, and that current A. carolinensis perch height is correlated with A. sagrei density. Our results suggest that character displacement likely interacts with other evolutionary processes in this system, and that temporal data are key to detecting such interactions.

opencc-by-4.0Mar 2014View details →

Figure 1 in Relationships between helminth communities and diet in Canarian lizards: the evidence from Gallotia atlantica (Squamata: Lacertidae)

Figure 1. Location of the islands and sampling sites where the different subspecies were collected.

opencc-by-nc-nd-4.0Jun 2020View details →

Data and R code for The Finer Points of Urban Adaptation: Intraspecific Variation in Lizard Claw Morphology (2020; Biological Journal of the Linnean Society)

This zip file contains all data (tps files, Rdata, csv) and annotated R script to conduct all analyses presented in Falvey et al. (2020, BJLS), which examines claw morphology in 5 species of anole lizards using geometric morphometrics.

Temporal variation in maternal nest choice and its consequences for lizard embryos

Microhabitat choice of nest sites is an important maternal effect that influences the survival and development of embryos in oviparous species. Embryos of many species display a high degree of plasticity in response to developmental environments, which places maternal nesting behavior under strong selective pressure, particularly in temporally-changing environments. Nesting behavior varies widely across taxa that exhibit diverse reproductive strategies. The brown anole (Anolis sagrei), for example, lays one egg every 7-10 days across an extended reproductive season from April to October. This aspect of their reproduction provides an opportunity to examine temporal shifts in nesting behavior and its consequences on egg survival and offspring development under seasonally-changing climatic conditions. We conducted a two-part study to quantify temporal variation in maternal nesting behavior and its effect on development of A. sagrei embryos. First, we measured nest microenvironments over the nesting season. Second, we "planted" eggs across the landscape at our field site to examine the influence of nest conditions on egg survival and hatchling phenotypes. We also incubated eggs inside chambers in the field to decouple effects of nest moisture from those of other environmental variables (e.g., temperature).Females chose nest sites with higher moisture and lower temperatures relative to what was generally available across the landscape during the nesting season. In addition, eggs exposed to relatively cool temperatures had higher hatching success, and high nest moisture increased egg survival and body condition of hatchlings. Overall, we provide evidence in the field that maternal nesting behavior facilitates offspring survival.

Locomotion and paleoclimate explain the re-evolution of quadrupedal body form in Brachymeles lizards

Evolutionary reversals, including re-evolution of lost structures, are commonly found in phylogenetic studies. However, we lack an understanding of how these reversals happen mechanistically. A snake-like body form has evolved many times in vertebrates, and occasionally, a quadrupedal form has re-evolved, including in Brachymeles lizards. We use body form and locomotion data for species ranging from snake-like to quadrupedal to address how a quadrupedal form could re-evolve. We show that large, quadrupedal species are faster at burying and surface locomotion than snake-like species, indicating a lack of expected performance trade-off. Species with limbs use them while burying, suggesting that limbs are useful for burying in wet, packed substrates. Paleoclimatological data suggest that Brachymeles originally evolved a snake-like form under a drier climate likely with soil<strike> </strike>in which it was easier to dig. The quadrupedal clade evolved as the climate became humid, where limbs and large size facilitated fossorial locomotion in packed soils.

Cellular and whole‐organism effects of prolonged versus acute heat stress in a montane, desert lizard

Global climate change involves both prolonged periods of higher-than-normal temperatures, and short but extreme heat waves. Both types of temperature increases are likely to be detrimental to ectotherms, and even if such temperature increases do not cause mortality directly, compensating for such temperature increases will likely entail costs to organisms. We tested the effects of prolonged periods of higher-than-average temperatures and short-term, acute heat stress in wild populations of greater short-horned lizards (Phrynosoma hernandesi), a temperate, montane lizard of the Colorado Plateau, U.S.A. We transplanted one group of lizards from a high- to a low-elevation site, exposing them to a prolonged period of warmer temperatures. These lizards, exposed to prolonged periods of higher-than-average temperatures, experienced no change in sprint speed, endurance, or heat shock protein production after treatment compared to baseline levels; however, they had lower water content after the transplant to a warmer climate compared to before the transplant. We exposed a second group of lizards to acute heat stress by exposing them to thermally stressful temperatures for four hours. These lizards, exposed to a short period of acute heat stress, had no change in endurance, water content, or heat shock protein production following acute heat stress; however, lizards exposed to acute heat stress had slower sprint speeds than control lizards. Our results demonstrate that both prolonged temperature increases and acute heat stress, each of which are predicted to occur with climate change, had different cellular and/or whole organismal-level effects on lizards.

Time of activity is a better predictor of the distribution of a tropical lizard than pure environmental temperatures

Environmental temperatures influence ectotherms' physiology and capacity to perform activities necessary for survival and reproduction. Time available to perform those activities is determined by thermal tolerances and environmental temperatures. Estimates of activity time might enhance our ability to predict suitable areas for species' persistence in face of climate warming, compared to the exclusive use of environmental temperatures, without considering thermal tolerances. We compare the ability of environmental temperatures and estimates of activity time to predict the geographic distribution of a tropical lizard, Tropidurus torquatus. We compared 105 estimates of activity time, resulting from the combination of four methodological decisions: (1) How to estimate daily environmental temperature variation (modeling a sinusoid wave ranging from monthly minimum to maximum temperature, extrapolating from operative temperatures measured in field or using biophysical projections of microclimate)? (2) In which temperature range are animals considered active? (3) Should these ranges be determined from body temperatures obtained in laboratory or in field? and (4) Should thermoregulation simulations be included in estimations? We show that models using estimates of activity time made with the sinusoid and biophysical methods had higher predictive accuracy than those using environmental temperatures alone. Estimates made using the central 90% of temperatures measured in a thermal gradient as the temperature range for activity also ranked higher than environmental temperatures. Thermoregulation simulations did not improve model accuracy. Precipitation ranked higher than thermally related predictors. Activity time adds important information to distribution modeling and should be considered as a predictor in studies of the distribution of ectotherms. The distribution of T. torquatus is restricted by precipitation and by the effect of lower temperatures on their time of activty and climate warming could lead to range expansion. We provide an R package "Mapinguari" with tools to generate spatial predictors based on the processes described herein.

Raw data accompanying: Ground reaction forces in monitor lizards (Varanidae) and the scaling of locomotion in sprawling tetrapods

Geometric scaling predicts a major challenge for legged, terrestrial locomotion. Locomotor support requirements scale identically with body mass (α M1), while force generation capacity should scale α M2/3 as it depends on muscle cross-sectional area. Mammals compensate with more upright limb postures at larger sizes, but it remains unknown how sprawling tetrapods deal with this challenge. Varanid lizards are an ideal group to address this question because they cover an enormous body size range while maintaining a similar bent-limb posture and body proportions. This study reports the scaling of ground reaction forces and duty factor for varanid lizards ranging from 7 g 37 kg. Impulses (force x time) scaled roughly as predicted by the inverted pendulum model (α M0.99-1.34) while peak forces (α M0.73-1.00) scaled higher than expected. Duty factor scaled α M0.04 and was higher for the hindlimb than the forelimb. The proportion of vertical impulse to total impulse increased with body size, and impulses decreased while peak forces increased with speed. These results provide valuable data into how locomotor forces vary with body size and suggest how other, extinct, sprawling tetrapods may have dealt with the biomechanical challenges associated with generating sufficient locomotor forces at larger body sizes.

opencc-by-4.0Jan 2021View details →

Dataset: The role of social costs as a mechanism enforcing the honesty of ultraviolet-reflecting signals in a lizard

Here are the data associated with the study entitled "The role of social costs as a mechanism enforcing the honesty of ultraviolet-reflecting signals in a lizard" authored by Anna Kawamoto, Jean-François Le Galliard, and Arnaud Badiane and published in Biological Journal of the Linnean Society. Four different data sets are provided and the Notes.xlsx file explains the content of these data sets. We also added three short videos showing typical lizards' behaviours scored in this study.

opencc-zeroJan 2021View details →

Recovered microbiome of an oviparous lizard differs across gut and reproductive tissues, cloacal swabs, and feces

Microbial diversity and community function are related, and both can be highly specialized in different regions of the gut. The cloacal microbiome of Sceloporus virgatus lizards has low diversity, suggesting a specialized function, and is known to transfer antifungal microbes to eggshells during oviposition. We hypothesize that the cloacal microbiome is distinct from other parts of the digestive and reproductive systems. Here, we compare the microbiome of tissue samples from the cloaca, lower intestine, upper intestine, and oviduct. We further assessed whether common methods of microbial sampling – cloacal swabs and feces – provide accurate representations of these tissues, and whether feces might "seed" the cloacal microbiome. We found that the upper intestine and oviduct had unique microbial communities, while the lower intestine and cloaca had similar communities with lower diversity indicative of regional specialization. The cloacal community, in particular, showed extreme specialization averaging 99% Proteobacteria (Phylum) and 83% Enterobacteriacaea (Family). Cloacal swabs recovered communities similar to that of lower intestine and cloacal tissues, but fecal samples had much higher diversity and a distinct composition (62% Firmicutes and 39% Lachnospiraceae) relative to all gut regions. This result serves as a caution against the frequent assumption that fecal samples provide an accurate representation of the gut. Finally, we found that defecation did not alter the cloacal microbiome, suggesting that community is robust to perturbations from transient microbiota.

opencc-zeroJan 2021View details →

The combined role of dispersal and niche evolution in the diversification of Neotropical lizards

Ecological requirements and environmental conditions can influence diversification across temporal and spatial scales. Understanding the role of ecological niche evolution under phylogenetic contexts provides insights on speciation mechanisms and possible responses to future climatic change. Large-scale phyloclimatic studies on the megadiverse Neotropics, where biomes with contrasting vegetation types occur in narrow contact, are rare. We integrate ecological and biogeographic data with phylogenetic comparative methods, to investigate the relative roles of biogeographic events and niche divergence and conservatism on the diversification of the lizard genus Kentropyx Spix, 1825 (Squamata: Teiidae), distributed in South American rainforests and savannas. Using five molecular markers, we estimated a dated species tree, which recovered three clades coincident with previously proposed species groups diverging during the mid-Miocene. Biogeography reconstruction indicates a role of successive dispersal events from an ancestral range in the Brazilian Shield and western Amazonia. Ancestral reconstruction of climatic tolerances and niche overlap metrics indicate a trend of conservatism during the diversification of groups from the Amazon Basin and Guiana Shield, and a strong signal of niche divergence in the Brazilian Shield savannas. Our results suggest that climatic-driven divergence at dynamic forest-savanna borders might have resulted in adaptation to new environmental niches, promoting habitat shifts and shaping speciation patterns of Neotropical lizards. Dispersal and ecological divergence could have a more important role in Neotropical diversification than previously thought.

opencc-zeroJan 2021View details →

Fire-driven behavioral response to smoke in a Mediterranean lizard

The evolutionary role of fire in animals has been poorly explored. Reptiles use sensory cues such as smell (chemoreception) to detect threats and flee. In Mediterranean ecosystems, fire is a threat faced by reptiles. We hypothesized that the Mediterranean lizard Psammodromus algirus recognizes the threat of fire by detecting the smoke, which triggers a behavioral response that enhances survival in fire-prone ecosystems. We predicted that lizards from fire-prone ecosystems will be more sensitive to fire stimulus than those from ecosystems that rarely burn. We conducted a terrarium experiment in which lizards from habitats with contrasted fire regimes (fire-prone vs. non-fire-prone) were exposed to smoke vs. control (false smoke) treatment. We found that in populations from fire-prone habitats, more lizards reacted to smoke, and their behavioral response was more intense than in lizard populations from non-fire-prone habitats. Our results suggest that an enhanced response to smoke may be adaptive in lizards from fire-prone ecosystems as it increases the chance for survival. We provide evidence that fire is likely an evolutionary driver shaping behavioral traits in lizard populations exposed to frequent wildfires. Understanding ecological and evolutionary processes shaping animal populations is relevant for species conservation in a changing fire regime world.

opencc-zeroDec 2016View details →

Data from: Lizards in pinstripes: morphological and genomic evidence for two new species of scincid lizards within Ctenotus piankai Storr and C. duricola Storr (Reptilia: Scincidae) in the Australian arid zone

The scincid lizard genus Ctenotus is one of the most species-rich genera of squamate reptiles, but few molecular phylogenetic studies have been undertaken on the group. Here we assess molecular and morphological variation within C. piankai and C. duricola, an arid-adapted pair of nominate species characterized by a pattern of thin pale longitudinal lines on a dark background that occur primarily in the western deserts and Pilbara region of Australia. We sequenced mitochondrial DNA and genome-wide restriction-site associated DNA (RAD) from geographically widespread samples of these lizard taxa, with particularly dense sampling from the Pilbara region. Phylogenetic analyses of the mitochondrial cytochrome B gene and approximately 5,000 nuclear loci identified four highly divergent lineages within the two taxa. The four genetically-defined populations were concordant with geography and are distinguishable based on multiple morphological and color pattern characters, despite appearing superficially similar in appearance. Despite limited mtDNA exchange between two lineages in the Pilbara, we found no evidence for ongoing gene flow across the nuclear genome. For the western desert lineages, there was no evidence of introgression for either mtDNA or nDNA in our data. To resolve the taxonomy of the group, we redescribe C. piankai and C. duricola, and recognize the two divergent lineages as new species: C. rhabdotus sp. nov., from the south-eastern Kimberley, Ord, Victoria River and northern Tanami Desert regions of Western Australia and the Northern Territory, and C. pallasotus sp. nov., from the western Pilbara and North West Cape regions of Western Australia.

opencc-zeroApr 2020View details →

Data from: Male rock lizards may compensate reproductive costs of an immune challenge affecting sexual signals

Sexual signals can be evolutionarily stable if they are condition dependent or costly to the signaler. One of these costs may be the trade-off between maintaining the immune system and the elaboration of ornaments. Experimental immune challenges in captivity show a reduction in the expression of sexual signals, but it is not clear whether these detrimental effects are important in nature and, more importantly, whether they have reproductive consequences. We designed a field experiment to challenge the immune system of wild male Carpetan rock lizards, Iberolacerta cyreni, with a bacterial antigen (LPS). The immune challenge decreased relative reflectance of UV structural and melanin-dependent sexual coloration in the throat and the lateral ocelli, whereas the carotenoid-dependent dorsal green coloration was not affected. Immune activation also decreased proportions of ergosterol and cholesta-5,7-dien-3-ol in femoral secretions. These results support a trade-off between the immune system and both visual and chemical sexual ornaments. Moreover, reproductive success of males, estimated with DNA microsatellites, depended on the expression of some color and chemical traits. However, the immune challenge did not cause overall differences in reproductive success, although it increased with body size/age in control but not in challenged males. This suggests the use of alternative reproductive strategies (e.g. forced matings) in challenged males, particularly in smaller ones. These males might consider that their survival probabilities are low and increase reproductive effort as a form of terminal investment in spite of their "low-quality" sexual signals and potential survival costs.

opencc-zeroJun 2021View details →

Novel Tests of the Key Innovation Hypothesis: Adhesive Toepads in Arboreal Lizards

Abstract The evolution of key innovations—unique features that enable a lineage to interact with the environment in a novel way—may drive broad patterns of adaptive diversity. However, traditional tests of the key innovation hypothesis, those which attempt to identify the evolutionary effect of a purported key innovation by comparing patterns of diversity between lineages with and without the key trait, have been challenged on both conceptual and statistical grounds. Here, we explore alternative, untested hypotheses of the key innovation framework. In lizards, adhesive toepad structures increase grip strength on vertical and smooth surfaces such as tree trunks and leaves and have independently evolved multiple times. As such, toepads have been posited as a key innovation for the evolution of arboreality. Leveraging a habitat use dataset applied to a global phylogeny of 2692 lizard species, we estimated multiple origins of toepads in three major clades and more than 100 origins of arboreality widely across the phylogeny. Our results suggest that toepads arise adaptively in arboreal lineages and are subsequently rarely lost while maintaining arboreal ecologies. Padless lineages transition away from arboreality at a higher rate than those with toepads, and high rates of invasion of arboreal niches by non-arboreal padbearing lineages provides further evidence that toepads may be a key to unlocking evolutionary access to the arboreal zone. Our results and analytical framework provide novel insights to understand and evaluate the ecological and evolutionary consequences of key innovations.

opencc-by-4.0Aug 2011View details →

Image 10 in Taxonomic status of the arboreal Skink Lizard Dasia halianus (Haly & Nevill, 1887) in Sri Lanka and the redescription of Dasia subcaeruleum (Boulenger, 1891) from India

Image 10. The sketch done by Annandale (1906) of the juvenile paralectotype.