Frederico Gustavo Rodrigues França

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.

Detecting Variation in Microhabitat Use in Low-Diversity Lizard Assemblages across Small-Scale Habitat Gradients

Abstract If community structure is influenced by habitat structure at a local level, then it should be possible to tie species occurrence to key habitat variables. We used a pitfall-trap system to determine the relationship of species composition, species diversity (relative abundance), and community structure to habitat structure along a transect through a habitat gradient in the Brazilian Cerrado. A total of 531 individuals of 12 lizard species were sampled. A species accumulation curve based on EstimateS and a curve-fitting protocol predicted 12 species at day 22 and all species by about day 40. We registered 12 species at day 11. Trapping success declined through time, likely because of a combination of removal along the transect and seasonal environmental change (wet to dry). The more open end of our transect experienced higher temperatures in all microhabitats sampled, suggesting thermal structure associated with vegetative structure. A Canonical Correspondence Analysis showed that lizard species composition and relative abundance respond to variation in vegetative and physical structure of the habitat at small scales. Consequently, maintenance of habitat gradients should be considered in programs aimed at maintaining local biodiversity.

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.

At the water's edge : Ecology of semiaquatic teiids in Brazilian Amazon

Abstract We describe activity patterns, diet, reproduction, sexual dimorphism, and thermal ecology of the semiaquatic teiids Crocodilurus amazonicus and Dracaena guianensis, from two localities in the Brazilian Amazon. Most C. amazonicus were first sighted in water or on open ground, were active during the hottest hours of the day, and usually had low body temperatures associated with substrate temperatures. Dracaena guianensis were found mainly perching on shrubs and used higher perches located closer to the center of lakes compared to C. amazonicus. Both species appear to rely primarily on crypsis to escape detection by predators but will dive into water as a final means of escape. Crocodilurus amazonicus has a broad diet which includes terrestrial and aquatic prey, particularly spiders and hemipterans, whereas D. guianensis feeds primarily on aquatic snails. No association between body dimensions and prey dimensions was evident. Sexual size dimorphism was not significant in either species, contrary to results reported for other teiids elsewhere, but males of C. amazonicus had relatively longer bodies and tails than females. Clutch size of both species was small relative to their body size and relative to other Amazon teiids, apparently influenced by their semiaquatic habits and by locomotor constraints. We found reproductive females during March (wet season) and July (dry season), suggesting an extended reproductive season.

Herpetofauna of protected areas in the Caatinga II: Serra da Capivara National Park, Piauí, Brazil

We provide a list of amphibians, lizards, chelonians, and snakes collected during a 30-day expedition to the Serra da Capivara National Park, Piaui State, Brazil. Thirty-seven pitfall trap arrays composed of 4 buckets each, along with glue traps, funnel traps, and haphazard searches, were used to sample the herpetofaunal diversity. We recorded 17 species of lizards, 1 caecilian, 1 chelonian, 7 frogs, and 11 snakes. Rarefaction curves suggest that local biodiversity is still underestimated. An atypical drought during the period of study may have contributed to lower captures of certain groups, especially amphibians and snakes. The presence of water-dependent and forest-dependent species within local canyons (“Boqueiroes”) suggests that these areas harbor faunas associated with relictual rainforest fragments and need to be better studied and managed accordingly.

Diversity, activity patterns, and habitat use of the snake fauna of Chapada dos Veadeiros National Park in Central Brazil

Chapada dos Veadeiros National Park (CVNP) in central Brazil is one of the most important protected areas of Brazilian Cerrado yet the diversity that this park harbors remains unknown for many taxa. From 2006 to 2009, we studied the snake assemblage of CVNP to determine the species composition, abundance, seasonal and daily activity patterns, morphology, and habitat use. We documented 47 snake species from seven families within CVNP, with the most common species being Bothrops marmoratus, Oxyrhopus trigeminus, Crotalus durissus and Bothrops moojeni. The incidence of snakes was highly seasonal and appeared to be associated mainly with rainfall. Daily activity patterns revealed that the majority of snakes are strictly diurnal, whereas others are nocturnal or active during both periods. Species richness estimators suggest that more snake species than the 47 we documented likely occur within CVNP, indicating that it harbors one of the richest snake faunas among South American open biomes studied to date.

Composition of a snake assemblage inhabiting an urbanized area in the Atlantic Forest of Paraíba State, Northeast Brazil

The Atlantic Forest of Brazil is one of the most biologically diverse regions in the world, but also one of the most highly threatened, with only around six percent of its original cover remaining. Despite the increase in the number of studies on the ecology of Brazilian snakes during the last two decades, there are still very few works on snake assemblages in the Northeast region and almost nothing about snakes inhabiting urbanized areas in Atlantic Forest domain. Herein we describe the snake assemblage from the urban area of Rio Tinto city in Paraiba State, Northeast Brazil. We present data on composition, distribution and some natural history. Also, we compare the snake diversity of the urban area with the diversity in two nearby natural patches. We recorded 161 individuals of 25 species in 16 genera from the urban area of Rio Tinto and the most common species were Helicops angulatus, Bothrops leucurus, Epicrates assisi, and Philodryas patagoniensis. Most snake species were non-venomous, but some venomous snakes were abundant in the urban area and people must be cautious when dealing with these. Rarefaction curves did not reach stability and new species should be added to the Rio Tinto snake list in future studies.

Wild vertebrate roadkill in the Chapada dos Veadeiros National Park, Central Brazil

Chapada dos Veadeiros National Park is one of the most important protected areas of the Brazilian Cerrado and is inhabited by diverse species, but the area has seldom been studied. From 2006 to 2008, we studied the impact of roads on wild vertebrates by recording roadkill on the two main roads located in the vicinity of the park. Of 824 killed vertebrates belonging to 138 species that were recorded, the species that were found most often in each vertebrate group were the Schneiders toad (Rhinella schneideri), the grassland sparrow (Ammodramus humeralis), the yellow-toothed cavy (Galea flavidens), and the marbled lancehead (Bothrops marmoratus). The roadkill rate was 0.096 animals km-1. Vertebrate mortality was significantly higher during the wet season. There is a significant relationship between habitat structure and the vertebrates that were found as roadkill: amphibians are associated with nearby forest and paved roads, birds with nearby pastures, reptiles with nearby grassland, and mammals with unpaved roads. Action should be taken such as highway fencing in combination with safe crossing opportunities for wildlife in order to decrease the number of animals killed on the roads.

Herpetofauna of protected areas in the Caatinga III: The Catimbau National Park, Pernambuco, Brazil

Despite the increase in herpetofaunal inventories in the Caatinga biome, information for many areas is still lacking and new surveys are required. We conducted a 30-day inventory of the herpetofauna of the Catimbau National Park, Pernambuco State, Brazil. Thirty-seven pitfall trap arrays composed of 4 buckets each, along with glue traps and active searches were used to sample local herpetofaunal diversity. We recorded 21 species of frogs, 25 lizards, 11 snakes, and 1 chelonian. All sampling methods contributed significantly to achieve the amphibian and reptile diversity recovered in the inventory. Rarefaction curves and richness estimators suggest that local biodiversity is still underestimated. We attempted to show the great potential of Catimbau National Park, characterized by the richest herpetofauna surveyed in a core region of the biome, along with the presence of endemic species such as the worm snake Amphisbaena supranumeraria and the limbless lizard Scriptosaura catimbau, underscoring the importance of the area for the conservation and maintenance of the Caatinga herpetofauna biodiversity.

Strobilurus torquatus Wiegmann, 1834 (Squamata: Tropiduridae): new records from the Brazilian state of Paraíba and a geographic distribution map

We provide the first records of torquatus from the Brazilian state of Paraiba and review its distribution based on specimens available in Brazilian collections and published data. This result emphasizes the need for more surveys on reptiles at this region.