Lizard Community Structure Research Articles

Factors shaping a lizard community structure in a semiarid region of north-eastern Brazil

We assessed the roles of historical and recent factors on the structure of a Neotropical lizard community from Serra da Capivara, in the semiarid Caatinga of north-eastern Brazil. We found no phylogenetic structure in community composition. Spatial niche overlap was high for most species pairwise comparisons. Null model analyses indicated that mean spatial and trophic niche overlaps did not differ, while mean morphological niche overlap was significantly lower than expected by chance, indicating a community structured along the morphological niche axis but not along the trophic nor spatial niche axes. We suggest that the lack of spatial niche segregation and species association may be related to current environmental conditions, such as habitat homogeneity and climatic variables. Morphological and dietary niches were influenced by historical factors, with phylogeny accounting for most of the variation in our data. Most of the variation is accounted for by the divergence of basal lineages (Gekkota/Scincomorpha/Iguania). These segregations influence behaviour and foraging modes of the given clades. Finally, these results are quite like those found for lizard communities in Seasonal Tropical Dry Forests (STDFs) and Cerrado savannahs, which can be a starting point to discuss the relationship between these formations to Caatinga domain.

Lizard community structure and spatial resource use along a forest-savannah-urban habitat gradient in the Dahomey Gap (West Africa)

Lizard community structure and spatial resource use along a forest-savannah-urban habitat gradient in the Dahomey Gap (West Africa)

Decline in lizard species diversity, abundance and ectoparasite load across an elevational gradient in the Australian alps

AbstractThe rapid changes in altitude, and associated habitat, of mountain ecosystems make them ideal natural laboratories for testing the effect of environmental heterogeneity on species assemblage. Our understanding of the sensitivity of Australian reptiles to elevational clines is limited. We examined lizard distribution across three elevation zones (montane, subalpine and alpine), spanning from 900 to 1840 m above sea level, in the Australian alps. We aimed to examine how elevation influences species diversity and abundance, and ectoparasite load, and whether species alter their habitat use amongst different elevational zones. Active searches were conducted across the elevation zones to identify lizard community structure (at least 16 species) across elevational zones, along with skink habitat preferences and the ectoparasite load. Skink diversity and abundance were negatively correlated with increased elevation. The alpine zone had significantly lower diversity and abundance of skinks. Habitat use differed amongst both elevations and species. Ectoparasite prevalence was also significantly diminished in the alpine zone. Ectoparasites only infected a subset of the skink community, with ectoparasite load increasing as the active season progressed. This study provides evidence of the complex interplay between elevation and species diversity, as well as the differences in ectoparasite pressure along elevational gradients in the Australian alps.

Long-term, fire-induced changes in habitat structure and microclimate affect Cerrado lizard communities

Fire transforms the structure of natural habitats and, consequently, modifies microclimates affecting ectotherm organisms that are particularly susceptible to changes in the thermal environment. Nevertheless, the effects of fire-induced microclimatic shifts upon natural populations have been neglected. We measured the central tendency and variation of habitat structural and microclimatic variables in experimental plots of Neotropical savanna vegetation subjected to different fire regimes and assessed their effects upon lizard community structure. In addition, we evaluated the underlying mechanisms linking fire-induced environmental changes to community structure, by comparing lizard body condition and survival between different fire regimes. Fire suppression promoted increased tree density, canopy cover and leaf-litter weight, whereas burning had the opposite effects, reducing the habitat structural complexity. The best predictors of fire regimes were means of structural variables, but variances of microclimatic variables, and the reduced structural complexity of burned plots both increased and decreased the variation of microclimatic variables. Lizard community structure was chiefly described by a gradient of decreasing tree density, canopy cover and leaf litter weight with increasing fire severity. About half of the lizard species were favored in the fire-protected plot, while the other half was favored in the burned plots, with most of the variation being explained by structural variables. Lizard body condition and survival rates were not affected by fire regimes, suggesting a dominant role of thermoregulation opportunities afforded by habitat structure—instead of food availability or predation rates—upon community structure. Our findings indicate that even sporadic fires can have profound effects upon lizard communities and that protecting some habitat patches from burning is essential to maximize lizard diversity in Cerrado landscapes.

Lizard assemblages on sandy coastal plains in southeastern Brazil: An analysis of occurrence and composition, and the role of habitat structure.

Data on the structure of lizard communities in the different biomes and ecosystems of Brazil are still limited. In this study, we related the species richness, abundance and the spatial occurrence of lizards to the structure of the vegetation found on the coast of the state of Espírito Santo, southeastern Brazil, to determine whether habitat influences the structure of lizard communities. We conducted fieldwork in 2012, 2013 and 2014, collecting data in standardized samples. We analyze whether variables of vegetation structure influenced species richness and abundance, using Generalized Linear Models (GLMs). We recorded 12 lizard species from eight families. In general, species richness and abundance were similar among sites. Locally, we recorded the highest species richness in shrubby vegetation, open Clusia vegetation, and the restinga forest zone. Bromeliads explained the occurrence of teiids, although there was no systematic relationship between species richness and vegetation structure. Our results provide important insights into the characteristics of the lizard communities found on sandy coastal plains and contribute to the conservation of these species in these ecosystems.

Non-random lizard extinctions in land-bridge Amazonian forest islands after 28 years of isolation

Major hydropower infrastructure has become a leading driver of biodiversity loss in the lowland tropics. Terrestrial species typically become stranded in post-isolation land-bridge islands within hydroelectric reservoirs. Understanding the resulting extinction dynamics of insular communities is critical to inform, if not to avert, the ongoing blitzkrieg of dam development. Here we assess the effects of forest patch and landscape metrics on diurnal lizard species richness and composition within the Balbina Hydroelectric Dam and surrounding areas in the Central Brazilian Amazon. This 28-yr-old dam created a reservoir of ~4438km2, comprising 3546 islands. We sampled 25 of these islands (0.83–1466ha) and five mainland continuous forest sites, one of which placed along stream banks. We further related morpho-ecological traits and the geographic distribution of lizard species to the spatial metrics of islands where they occurred. Using 100L-pitfall traps operated over 5447 trap-days, we recorded 1123 lizards from 17 taxa, two of which exclusively found along stream banks within continuous forest. Island area was the best predictor of species richness and composition. Small islands (≤2ha) harboured fewer than a third of all species typically observed in larger islands and continuous forest (≥8 species), and only islands ≥100ha retained nearly complete lizard faunas. Lizard assemblages inhabiting small, isolated islands consisted almost exclusively of an oversimplified set of widely distributed, large-bodied, habitat generalist, heliophile species associated with open areas and forest edges, and that feed on a wide spectrum of prey sizes. These wholesale changes in lizard community structure were characterized by severe losses in functional traits, and may profoundly affect ecosystem functioning.

Juxtaposition and Disturbance: Disentangling the Determinants of Lizard Community Structure

AbstractDisturbance alters the structure and dynamics of communities. Here, we examined the effects of seasonal flooding on the lizard community structure by comparing two adjacent habitats, a seasonally flooded and a non‐flooded forest, in a Cerrado–Amazon ecotone area, the Cantão State Park, Tocantins state, Brazil. Despite the strong potential impact of seasonal flooding, the only significant environmental difference detected was more termite mounds in non‐flooded forests. Species richness was significantly higher in the non‐flooded forest. Colobosaura modesta, followed by Mabuya frenata and Anolis brasiliensis, were the only species that differed in number of captures between sites. Colobosaura modesta was exclusively found in the non‐flooded forest, while Anolis brasiliensis was the most captured in the flooded forest. Mabuya frenata is indicated as an indicator species in the flooded forest, and Colobosaura modesta in the non‐flooded forest. We found a significant association between lizard abundances and habitat characteristics, with flooding, canopy cover, and logs being the best predictors. A phylogenetic community structure analysis indicated a lack of structure in both lizard assemblages. Overall, we show that seasonal flooding can strongly impact species richness and species occurrence patterns, but not phylogenetic community structure. The Amazon–Cerrado transition is undergoing pronounced transformations due to deforestation and climate change. Despite being species‐poor compared with central areas in Amazon or Cerrado, this ecotone harbors species with important adaptations that could hold the key to persistence in human‐disturbed landscapes or during periods of climate change.

Response of lizard community structure to desert grassland restoration mediated by a keystone rodent

Many grasslands in the Chihuahuan Desert have transformed to shrublands dominated by creosotebush (Larrea tridentata). Grassland restoration efforts have been directed at controlling creosotebush by applying herbicide over large spatial scales. However, we have a limited understanding of how landscape-scale restoration affects biodiversity. We examined whether restoration treatments in southern New Mexico, USA have influenced the community structure of lizards, which are sensitive to shrub encroachment. We compared lizard community structure on 21 areas treated with herbicide from 7 to 29 years ago with paired untreated areas that were dominated by shrubs and matched by geomorphology, soils, and elevation. To examine mechanisms underlying responses to restoration, we tested whether the abundance of a grassland specialist, Aspidoscelis uniparens, depended on time since treatment, treatment area and isolation, and local habitat quality. Because lizards use rodent burrows as habitat, we tested whether community structure and A. uniparens abundance depended on the abundance of the keystone rodent, Dipodomys spectabilis. Treated areas had reduced shrub cover and increased grass cover compared to untreated areas. Lizard community composition differed strongly between areas, with four species responding to treatments. Divergence in community composition between treated–untreated pairs was greatest for old treatments (≥22 years), and community composition was influenced by D. spectabilis. In particular, the abundance of A. uniparens was greatest on old treatments with a high density of D. spectabilis. Overall, our results demonstrate lizard community structure responds to grassland restoration efforts, and keystone species can shape restoration outcomes. Reestablishment of keystone species may be a critical constraint on the recovery of animal biodiversity after habitat restoration.

Lizard community structure along environmental gradients

1. How the total number of individuals in a community is divided among its species is governed by both the distribution of species along landscape-scale environmental gradients and by local resource partitioning. In vertebrate ectotherms, abiotic environmental conditions may constrain geographic distributions more strongly than local population densities due to thermal constraints on resource acquisition and due to behavioural thermoregulation. 2. We investigate whether local density and species richness are decoupled for lizard communities within the Southwest US by comparing 18 species-abundance distributions. 3. While species richness decreases strongly with decreasing temperature, there is no significant relationship between temperature or resource availability (net primary productivity) and the total number of individuals within a community. Consequently, in more species-rich communities species have lower mean abundances. 4. This suggestion that lizard species richness is not a function of an area's capacity to support more individuals questions for this group species diversity theories based on this assumption.

Evaluating the Effectiveness of Herpetofaunal Sampling Techniques across a Gradient of Habitat Change in a Tropical Forest Landscape

To improve our understanding of the distribution and abundance of amphibians and reptiles in tropical forests, herpetologists need to understand the relative effectiveness of different sampling techniques. However, current studies are biased by a focus on certain methods, species groups, or geographic regions. To address this problem, we conducted the first standardized comparison of patterns of species richness, rank-abundance, and community structure for both passive and active sampling methods for the study of herpetofauna in a tropical forest landscape. Moreover, we compare the effectiveness of these methods in primary and secondary forests and Eucalyptus plantation. Although different methods captured significantly different numbers of species and individuals, almost all techniques provided complementary benefits for the sampling of both lizards and leaf litter amphibians. The use of a limited set of methods can severely bias our understanding of changes in amphibian and lizard community structure in response to large-scale habitat change. Contrary to other studies, we recommend the use of pitfall traps in all studies, even Rapid Assessments (RAP), because they are indispensable for sampling many cryptic species, as well as being particularly cost effective for large-scale research. Because of the combination of complementary methods in sampling effectiveness, and the influence of method choice on taxon responses to habitat change, we recommend the use of multiple sampling techniques wherever possible. Synchronous adoption of multiple techniques in field studies will help improve sample representation and, thus, the understanding of species distributions and human impacts on herpetofauna in tropical forests.

Introduction: Merging Evolutionary and Ecological Approaches to Understanding Geographic Gradients in Species Richness

Next article No AccessIntroduction: Merging Evolutionary and Ecological Approaches to Understanding Geographic Gradients in Species RichnessSusan Harrison and Howard V. CornellSusan HarrisonDepartment of Environmental Science and Policy, University of California, Davis, California 95616*E‐mail: [email protected]. Search for more articles by this author and Howard V. CornellDepartment of Environmental Science and Policy, University of California, Davis, California 95616 Search for more articles by this author Department of Environmental Science and Policy, University of California, Davis, California 95616PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 170, Number S2August 2007Merging Evolutionary and Ecological Approaches to Understanding Geographic Gradients in Species RichnessA Symposium Organized by Susan Harrison Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/519011 Views: 67Total views on this site Citations: 17Citations are reported from Crossref © 2007 by The University of Chicago.PDF download Crossref reports the following articles citing this article:Cleiber Marques Vieira, Denise Carneiro Melo Padrões biogeográficos de variação do tamanho de quirópteros brasileiros: testando a regra de Bergmann, Revista Científica Multidisciplinar Núcleo do Conhecimento (Dec 2022): 05–25.https://doi.org/10.32749/nucleodoconhecimento.com.br/biologia/quiropteros-brasileirosSabrina S. Gavini, Cecilia Ezcurra, Marcelo A. Aizen, Francisco Pugnaire Patch‐level facilitation fosters high‐Andean plant diversity at regional scales, Journal of Vegetation Science 31, no.66 (Aug 2020): 1133–1143.https://doi.org/10.1111/jvs.12922João Fabrício Mota Rodrigues, Fernando Landa Sobral, John B. Iverson, José Alexandre Felizola Diniz‐Filho , Journal of Biogeography 46, no.44 ( 2019): 671.https://doi.org/10.1111/jbi.13527Qinggang Wang, Xiangyan Su, Nawal Shrestha, Yunpeng Liu, Siyang Wang, Xiaoting Xu, Zhiheng Wang Historical factors shaped species diversity and composition of Salix in eastern Asia, Scientific Reports 7, no.11 (Feb 2017).https://doi.org/10.1038/srep42038Tae-Sung Kwon, Sung-Soo Kim, Jung Hwa Chun Pattern of ant diversity in Korea: An empirical test of Rapoport's altitudinal rule, Journal of Asia-Pacific Entomology 17, no.22 (Jun 2014): 161–167.https://doi.org/10.1016/j.aspen.2013.12.006PATRICK. H. KAVANAGH, KEVIN. C. BURNS Mistletoe macroecology: spatial patterns in species diversity and host use across Australia, Biological Journal of the Linnean Society 106, no.33 (May 2012): 459–468.https://doi.org/10.1111/j.1095-8312.2012.01890.xS. Pavoine, M. B. Bonsall Measuring biodiversity to explain community assembly: a unified approach, Biological Reviews 86, no.44 (Dec 2010): 792–812.https://doi.org/10.1111/j.1469-185X.2010.00171.xHallvard Haanes, Bjørn Gulliksen A high local species richness and biodiversity within high-latitude calcareous aggregates of tube-building polychaetes, Biodiversity and Conservation 20, no.44 (Jan 2011): 793–806.https://doi.org/10.1007/s10531-010-9980-0Alvar Carranza, Omar Defeo, Matías Arim Taxonomic relatedness and spatial structure of a shelf benthic gastropod assemblage, Diversity and Distributions 17, no.11 (Nov 2010): 25–34.https://doi.org/10.1111/j.1472-4642.2010.00720.xMichael Kessler Biogeography of ferns, (Jun 2010): 22–60.https://doi.org/10.1017/CBO9780511844898.003Lauren B. Buckley, Walter Jetz Lizard community structure along environmental gradients, Journal of Animal Ecology 79, no.22 (Mar 2010): 358–365.https://doi.org/10.1111/j.1365-2656.2009.01612.xS. Bruce Archibald, William H. Bossert, David R. Greenwood, Brian D. Farrell Seasonality, the latitudinal gradient of diversity, and Eocene insects, Paleobiology 36, no.33 (Apr 2016): 374–398.https://doi.org/10.1666/09021.1Nicholas J. Gotelli, Marti J. Anderson, Hector T. Arita, Anne Chao, Robert K. Colwell, Sean R. Connolly, David J. Currie, Robert R. Dunn, Gary R. Graves, Jessica L. Green, John-Arvid Grytnes, Yi-Huei Jiang, Walter Jetz, S. Kathleen Lyons, Christy M. McCain, Anne E. Magurran, Carsten Rahbek, Thiago F.L.V.B. Rangel, Jorge Soberón, Campbell O. Webb, Michael R. Willig Patterns and causes of species richness: a general simulation model for macroecology, Ecology Letters 12, no.99 (Sep 2009): 873–886.https://doi.org/10.1111/j.1461-0248.2009.01353.xAlvar Carranza, Omar Defeo, Juan Carlos Castilla, Thiago Fernando L. V. B. Rangel Latitudinal gradients in species richness for South American Mytilidae and Ostreidae: can alternative hypotheses be evaluated by a correlative approach?, Marine Biology 156, no.99 (May 2009): 1917–1928.https://doi.org/10.1007/s00227-009-1224-zSusan Harrison, Howard Cornell Toward a better understanding of the regional causes of local community richness, Ecology Letters 11, no.99 (Sep 2008): 969–979.https://doi.org/10.1111/j.1461-0248.2008.01210.xJonathan A. D. Fisher, Kenneth T. Frank, Brian Petrie, William C. Leggett, Nancy L. Shackell Temporal dynamics within a contemporary latitudinal diversity gradient, Ecology Letters 11, no.99 (Sep 2008): 883–897.https://doi.org/10.1111/j.1461-0248.2008.01216.xJoaquín Hortal, Jesús Rodríguez, Manuel Nieto-Díaz, Jorge M. Lobo Regional and environmental effects on the species richness of mammal assemblages, Journal of Biogeography 35, no.77 (Jul 2008): 1202–1214.https://doi.org/10.1111/j.1365-2699.2007.01850.x

Lizard community structure across a grassland – creosote bush ecotone in the Chihuahuan Desert

I investigated the distribution and abundance of lizard species (Aspidoscelis inornatus, Aspidoscelis tesselatus, Aspidoscelis tigris, Aspidoscelis uniparens, Cophosaurus texanus, Crotaphytus collaris, Eumeces obsoletus, Gambelia wislizenii, Holbrookia maculata, Phrynosoma cornutum, Sceloporus magister, and Uta stansburiana) across a desert grassland – creosote bush (Larrea tridentata) ecotone in Dona Ana County, New Mexico. The ecotonal area in the Jornada del Muerto basin has increased dramatically in the past 150 years because of the rapid spread of creosote bush. I asked four related questions: how large and where is the ecotone based on vegetative structure, and do lizard abundance and diversity change across the ecotone? Vegetation data were analyzed using discriminate function analysis to determine the extent of the ecotone. Changes in lizard abundance across the ecotone were analyzed by analysis of variance. During two summers, 677 individual lizards of 9 genera and 12 species were captured. Lizard abundance increased with increasing distance from the ecotone and was similar in grassland and creosote bush habitat. Grasslands had higher species richness than both the creosote bush and ecotone habitats. Grassland sites had greater habitat heterogeneity than did creosote bush sites. No ecotone specialist species were detected, and all common lizard species could be found in each habitat. Three potential explanations for decreased abundance in the ecotone are presented: (1) increased risk of predation, (2) decreased prey abundance, and (3) lack of species-specific microhabitat requisites.

Ecological Differences in Tropical Sympatric Skinks (Mabuya macrorhyncha and Mabuya agilis) in Southeastern Brazil

Ecological Differences in Tropical Sympatric Skinks (Mabuya macrorhyncha and Mabuya agilis) in Southeastern Brazil

Results of Experimental Density Manipulation in An Arizona Lizard Community

A study of three species of sceloporine lizards (Sceloporus clarki, S. undulatus, and Urosaurus ornatus) was begun in 1971 and continued into 1977 in a very diverse (at least 11 species) lizard community in central Arizona, USA. The present paper reports the results of a density manipulation experiment carried out with these three lizards to ascertain whether direct evidence for interspecific competition could be found in a community of lizards in which circumstantial evidence suggested its importance. In May 1975 the study area was divided along a natural constriction into an experimental area and a control area and an attempt was made to remove all U. ornatus and S. clarki from the experimental areas. This experimental treatment was maintained until the termination of the experiment in 1977. Patterns of habitat utilization, population density, survivorship, and individual body size of S. undulatus on experimental and control areas both before and after the removals were analyzed for evidence of competitive interactions. There were no detectable effect of the removal of S. clarki and U. ornatus on habitat selection, perch height, survivorship, population density, or individual body size of S. undulatus inhabiting the removal area. Implications of these results for studies of lizard community structure are discussed.

Ecological Convergence of Lizard Communities in Chile and California

Convergence in community structure, under similar long—term climatic conditions, were investigated using taxonomically unrelated lizard communities in Mediterranean climatic areas in central Chile and southern California. The hypothesis of convergence, i.e., physiognomically similar sites in the two continents should have lizard community structures that are more similar to each other than to the structure of lizard communities in nearby areas in the same transect, was tested by comparing the structure of lizard communities in an altitudinal–vegetational transect in each continent. Each transect consisted of a coastal sage, chaparral, and forested montane site. Structure of the lizard communities was characterized by the patterns of habitat, food, and time of activity of the lizard species. For each of these dimensions the total range of resources used by the community as a whole was determined, as well as the utilization pattern of individual species. Utilization patterns of individual species were expressed in a multidimensional vector in which the angle between vectors representing these patterns was used as a measure of ecological similarity between species. The vector method allowed determination of species pairs exhibiting the most similar patterns of resource utilization. The comparison strongly supports the convergence hypothesis. For habitat and time of activity, range of resources used as well as utilization functions of individual species were more similar in equivalent sites in the two continents than in nearby sites in the same continent. Thus, on the average the most similar species (species analogue) is on the equivalent site in the other transect and not in the same continent. Also, in general, the proportions of lizards found, irrespective of species, are the same on analogous resources in the two continents. Habitat species analogues found by comparing sites also similarly partitioned food resources. However, there are some differences in food categories used, since two of the Chilean species eat some vegetation (fruits), but their Californian size—habitat counterparts do not. In addition, the two chaparral sites show very similar mechanisms of generation replacement such that adults go into aestivation by the time hatchings appear. Evidence supporting the hypothesis of a seasonally shrinking food supply as the cause for this pattern is also given.

The Structure of Lizard Communities

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes, ...Read More