Cristiano Nogueira

Sampling bias and the use of ecological niche modeling in conservation planning: a field evaluation in a biodiversity hotspot

Ecological niche modeling (ENM) has become an important tool in conservation biology. Despite its recent success, several basic issues related to algorithm performance are still being debated. We assess the ability of two of the most popular algorithms, GARP and Maxent, to predict distributions when sampling is geographically biased. We use an extensive data set collected in the Brazilian Cerrado, a biodiversity hotspot in South America. We found that both algorithms give richness predictions that are very similar to other traditionally used richness estimators. Also, both algorithms correctly predicted the presence of most species collected during fieldwork, and failed to predict species collected only in very few cases (usually species with very few known localities, i.e., <5). We also found that Maxent tends to be more sensitive to sampling bias than GARP. However, Maxent performs better when sampling is poor (e.g., low number of data points). Our results indicates that ENM, even when provided with limited and geographically biased localities, is a very useful technique to estimate richness and composition of unsampled areas. We conclude that data generated by ENM maximize the utility of existing biodiversity data, providing a very useful first evaluation. However, for reliable conservation decisions ENM data must be followed by well-designed field inventories, especially for the detection of restricted range, rare species.

Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

Background Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. Methodology/Principal Findings Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. Conclusions/Significance We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems. Proper management (e. g. forestry code enforcement, landscape planning) and conservation (e. g. formal protection) of the 540 watersheds detected herein will be decisive in avoiding species extinction in the richest aquatic ecosystems on the planet.

Ecology of Bothrops neuwiedi pauloensis (Serpentes: Viperidae: Crotalinae) in the Brazilian Cerrado

Abstract We provide ecological information on Bothrops neuwiedi pauloensis (Amaral, 1925) regarding geographical distribution, habitat use, biometry, feeding habits, and reproduction, based on field studies and analysis of 175 preserved specimens. Bothrops n. pauloensis is endemic to the Brazilian Cerrado, where it occurs in open, seasonally dry savannas. Sexes are dimorphic in body length, relative tail length and relative body mass, but not in relative head length or diet. A wide array of prey, from centipedes to rodents, is consumed, and there is an ontogenetic dietary shift from ectotherms to endotherms. Prey-predator mass ratios ranged from 0.006–0.571. Although prey mass increased with snake mass, large snakes also ate many small prey. There was no difference in relative prey mass between sexes. Reproduction was highly seasonal, with a long vitellogenic period. Embryos were found only from October to December (rainy season). Litter size ranged from 4–20, and was dependent on female size. Although B. n. pauloensis occupies seasonally dry savannas, its ecological characteristics are similar to those described for Bothrops species inhabiting forested habitats.

Phylogeny and Ecology Determine Morphological Structure in a Snake Assemblage in the Central Brazilian Cerrado

Abstract To investigate the role of ecological and historical factors in the organization of communities, we describe the ecomorphological structure of an assemblage of snakes (61 species in six families) in the Cerrado (a savanna-like grassland) of Distrito Federal, Brazil. These snakes vary in habits, with some being fossorial, cryptozoic, terrestrial, semi-aquatic, or arboreal. Periods of activity also vary. A multivariate analysis identified distinct morphological groups associated with patterns of resource use. We report higher niche diversification compared to snakes in the Caatinga (a semi-arid region in northeastern Brazil), with fossorial and cryptozoic species occupying morphological space that is not occupied in the Caatinga. Monte Carlo permutations from canonical phylogenetic ordination revealed a significant phylogenetic effect on morphology for Colubridae, Colubrinae, Viperidae, Elapidae, and Boidae indicating that morphological divergence occurred in the distant past. We conclude that phylogeny is the most important factor determining structure of this Neotropical assemblage. Nevertheless, our results also suggest a strong ecological component characterizes a peculiar snake fauna.

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

Abstract 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.

Squamate reptiles from Parque Nacional das Emas and surroundings, Cerrado of Central Brazil

We present a list of squamate reptiles from Parque Nacional da Emas (PNE), ten neighbor private properties and Parque Estadual Nascentes do Rio Taquari, states of Goias, Mato Grosso, and Mato Grosso do Sul. The study area encompasses the headwaters of Araguaia and Taquari river basins and part of Paranaiba River Basin, resulting in significant habitat heterogeneity. Inside PNE, we recorded 74 squamate species: 47 snakes, 21 lizards and six amphisbaenians. If we consider also the neighboring areas, richness value raises to 87 species: 54 snakes, 27 lizards and six amphisbaenians. From these, 52 % of the lizards, 19 % of the snakes and 33 % of the amphisbaenians are Cerrado endemics. Forest-specialist species are more common outside than inside PNE. Additional species are expected to occur in the PNE region, in view of their known geographical ranges.

Composição e diversidade de répteis Squamata na região sul do Parque Nacional Grande Sertão Veredas, Brasil Central

Recoder, R. & Nogueira, C. Diversity and composition of squamate reptiles in the southern portion of Grande Sertao Veredas National Park, Central Brazil. Biota Neotrop. Sep/Dez 2007 vol. 7, no. 3 http://www. biotaneotropica.org.br/v7n3/pt/abstract?inventory+bn01107032007. ISSN 1676-0603. We present the results of an inventory of squamate reptiles from Grande Sertao Veredas National Park region, in the Brazilian Cerrado hotspot. We used standardized sampling methods to provide richness, diversity and distribution data and compared our results with those from other Cerrado localities. The regional squamate fauna is composed of at least 50 species, of which 25 lizards, three amphisbaenians and 22 snakes, distributed in 12 families: Polychrotidae (1), Tropiduridae (3), Scincidae (4), Teiidae (3), Gymnophthalmidae (6), Anguidae (1), Amphisbaenidae (3), Anomalepididae (1), Leptotyphlopidae (1), Boidae (2), Colubridae (16) e Viperidae (2). Recorded and estimated richness indicates that the region can be one of the richest in the Brazilian Cerrado. The recorded species present predictable abundance variations among different available habitats, a probable result of the influence of phylogenetic factors in the spatial distribution of the species. The “carrasco” habitat was distinguished for harboring two restricted species to the region: Stenocercus quinarius and Psilophthalmus sp., and should receive further attention in future studies. The open habitats, especially the typical open physiognomies of Cerrado, present the highest richness levels, in agreement with results in other Cerrado localities, a fact with direct implications for the conservation of central Brazilian savannas.

Anfíbios da Estação Ecológica Serra Geral do Tocantins, região do Jalapão, Estados do Tocantins e Bahia

The Northern part of Cerrado is one of the biologically poorest known areas in the domain. Recent studies revealed richness values that are as high as those from other sites in the domain. The Estacao Ecologica Serra Geral do Tocantins is located in a region known as Jalapao, in Northeastern Cerrado, and it is included in the largest set of protected areas in the domain. We describe amphibian richness and species composition in EESGT, and discuss it in a biogeographic context. We also describe breeding sites focusing on phytophysiognomy and types of water bodies. We sampled amphibians through active search and pitfall traps, during the peak of breeding season for most of the anuran species in Cerrado. We registered 36 species, which coupled with former studies results in a regional richness of 39 species known for Jalapao. After applying Jackknife estimator, we suggest a potential richness of 42 species for the EESGT. Most registered species are endemic or strongly associated to Cerrado, followed by species widespread in Brazil or South America, and those associated with Caatinga. Most species breed in temporary ponds located in open areas, although there are some forest specialists, and stream-breeding species.

Reproduction, Body Size, and Diet of Polychrus acutirostris (Squamata: Polychrotidae) in Two Contrasting Environments in Brazil

Abstract We compared reproduction, diet, and body size of Polychrus acutirostris (Squamata: Polychrotidae) from the Cerrado and Caatinga biomes in Brazil. Because these two biomes have widely different climates, we predicted that lizards in Caatinga would produce smaller clutches in response to rainfall unpredictability. We also expected reproductive timing to differ between biomes, with lizards occurring in the Cerrado producing a single clutch in association with the predictable rains of October–November. Contrary to expectations, clutches had fewer (although larger) eggs in Cerrado. Reproductive period was remarkably similar (peak of female reproductive activity in November), but female reproduction started 1 month earlier in Cerrado. Diet composition was also similar, with the exception of spiders, that exhibited a high index of relative importance in Cerrado but were nearly absent in Caatinga lizard diets. Lizards from both biomes ingested a large proportion of plant material, as well as soft-bodied arboreal arthropods, such as orthopterans, and mostly slow-moving, large arboreal insects. Rainfall predictability in the Cerrado therefore did not influence Polychrus reproduction or diet in the same manner as in other lizard species. The large number of small eggs in the Caatinga suggests that the competitive environment for offspring is either unpredictable or that mortality is high but random. Rain forest Polychrus lizards produce few large eggs, suggesting that the competitive environment for offspring is predictably intense and mortality is non-random. Cerrado Polychrus lizards seem intermediate between Caatinga and rain forest Polychrus lizards, producing fewer and larger eggs than their conspecifics in the Caatinga but relatively more and smaller eggs than rain forest Polychrus species.

The global distribution of tetrapods reveals a need for targeted reptile conservation

The distributions of amphibians, birds and mammals have underpinned global and local conservation priorities, and have been fundamental to our understanding of the determinants of global biodiversity. In contrast, the global distributions of reptiles, representing a third of terrestrial vertebrate diversity, have been unavailable. This prevented the incorporation of reptiles into conservation planning and biased our understanding of the underlying processes governing global vertebrate biodiversity. Here, we present and analyse the global distribution of 10,064 reptile species (99% of extant terrestrial species). We show that richness patterns of the other three tetrapod classes are good spatial surrogates for species richness of all reptiles combined and of snakes, but characterize diversity patterns of lizards and turtles poorly. Hotspots of total and endemic lizard richness overlap very little with those of other taxa. Moreover, existing protected areas, sites of biodiversity significance and global conservation schemes represent birds and mammals better than reptiles. We show that additional conservation actions are needed to effectively protect reptiles, particularly lizards and turtles. Adding reptile knowledge to a global complementarity conservation priority scheme identifies many locations that consequently become important. Notably, investing resources in some of the world’s arid, grassland and savannah habitats might be necessary to represent all terrestrial vertebrates efficiently.The global distribution of nearly all extant reptile species reveals richness patterns that differ spatially from that of other taxa. Conservation prioritization should specifically consider reptile distributions, particularly lizards and turtles.