Life-history information constitutes the raw data for building population models used in species ... more Life-history information constitutes the raw data for building population models used in species conservation. We provide life-history data for the endangered Santa Catalina Island Rattlesnake, Crotalus catalinensis. We use data from 277 observations of C. catalinensis made between 2002 and 2011 on the island. Mean snout-vent length (SVL) of adult C. catalinensis was 643 mm for males and 631 mm for females; the difference was not significant. The degree of sexual size dimorphism (SSD; using SVL) was -0.02. However, sexes were dimorphic in total length (SVL + tail length), relative tail length, and stoutness. Juvenile recruitment occurs during late-summer. In their first year of life, juveniles seem to grow at a rate of about 1.7 cm/mo. Females seem to become mature around 570 mm SVL, probably in the year when they become 2 y old. Scattered literature data corroborates the time of juvenile recruitment described herein. Growth in C. catalinensis seems to be slower than that of C. rube...
The dipsadid snake genus Tropidodryas consists of two species that occur in the Atlantic Forest a... more The dipsadid snake genus Tropidodryas consists of two species that occur in the Atlantic Forest along Brazil's eastern coast, a conservation hot spot. Life-history information on pairs of sister species might allow insights into the evolutionary transitions that have occurred since the cladogenesis that putatively gave rise to them. We provide information on distribution, morphology, diet, reproduction, and seasonal activity of these species based on the examination of 624 specimens. The genus Tropidodryas occurs along a large extent of the Atlantic Forest of eastern Brazil, with T. striaticeps occurring at higher elevations, on average, than T. serra. These snakes forage by day either on the ground or in vegetation, consuming a wide variety of vertebrates, mainly mammals. Higher proportions of birds in the diet of T. serra and certain mammals in the diet of T. striaticeps probably reflect elevational differences in prey availability. An ontogenetic diet shift occurs in both species, with juveniles consuming mainly ectothermic prey (lizards and anurans), and adults preying predominantly on mammals. Caudal luring has been documented in juveniles, but the pale color and high frequency of injuries on the tail of larger individuals indicate that adult T. striaticeps also employ this technique to attract prey. Sexual dimorphism occurs in body size, tail size, and diameter of the eye. Female reproductive cycles are seasonal in both species, with egg laying occurring in warmer periods of the year. However, T. striaticeps seems to have a more extended reproductive cycle, with some females being able to lay eggs 1 or 2 mo earlier. Environmental differences between high and low altitudes in the Atlantic Forest are likely responsible for the slight ecological divergence between these two closely related snakes.
We studied the defensive strike of one species of each of five recognized lineages within the gen... more We studied the defensive strike of one species of each of five recognized lineages within the genus Bothrops, namely, B. alternatus, B. jararaca, B. jararacussu, B. moojeni and B. pauloensis. The defensive strike of the studied species was in general similar to that of Crotalus viridis and C. atrox, but some important differences were observed. Bothrops alternatus and B. pauloensis struck preferentially from a tight body posture, whereas B. jararaca and B. moojeni from a loose body posture. Defensive strikes were either true or false (during the latter, the mouth remains closed or partially open). Almost all strikes were successful; only on a few occasions snakes missed their target (flawed strikes). Strike variables were very conservative among the five species, especially strike distance and height, and one possible explanation may be related to constraints imposed on strike variables as a way of increasing strike accuracy.
The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is ... more The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is suggested to have acted as a dispersal barrier for terrestrial organisms by fragmenting a single large forest that existed in South America into the present Atlantic and Amazon forests. Here we tested the hypothesis that the expansion of the South American diagonal of open/dry landscapes acted as a vicariant process for forest lanceheads of the genus Bothrops, by analyzing the temporal range dynamics of those snakes. We estimated ancestral geographic ranges of the focal lancehead clade and its sister clade using a Bayesian dated phylogeny and the BioGeoBEARS package. We compared nine Maximum Likelihood models to infer ancestral range probabilities and their related biogeographic processes. The best fitting models (DECTS and DIVALIKETS) recovered the ancestor of our focal clade in the Amazon biogeographic region of northwestern South America. Vicariant processes in two different subclades...
Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being ... more Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being endemic to this ecoregion. However, the Atlantic forest is one of the most threatened tropical ecoregions, with only 16% of its original area remaining as forest. This extensive habitat loss must have had a negative effect on its snake fauna. Indeed, 53% of the threatened snakes of Brazil occur in the Atlantic forest. Therefore, basic natural history information that can potentially contribute to the conservation of Atlantic forest snakes are urgently needed. Here the natural history of a snake assemblage at Etá Farm region, Sete Barras municipality, south-eastern Brazil is described, and a visual guide and an identification key provided that can be used by researchers and local people to identify snakes from this region. Most of the species found in the field use both open areas and forests, are primarily terrestrial, present diurnal activity, and include frogs in their diet. A higher n...
We provide information on the diversity and natural history of anurans from preserved and disturb... more We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Etá Farm, municipality of Sete Barras, state of São Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Etá Farm is necessary to preserve the diverse amphibian fauna of this region.
Rare species tend to be especially sensitive to habitat disturbance, making them important conser... more Rare species tend to be especially sensitive to habitat disturbance, making them important conservation targets. Thus, rarity patterns might be an important guide to conservation efforts. Rabinowitz’s approach defines rarity using a combination of geographical range, habitat specificity, and local abundance, and is frequently used in conservation prioritization. Herein, we use Rabinowitz’s approach to classify the New World (NW) pitvipers (family Viperidae) regarding rarity. We tested whether body size and latitude could predict rarity, and we compared rarity patterns with extinction risk assessments and other prioritization methods in order to detect rare species not classified as threatened or prioritized. Most NW pitvipers have large geographical ranges, high local abundances, and narrow habitat breadths. There are 11.8% of NW pitviper species in the rarest category and they occur along the Pacific coast of Mexico, in southern Central America, in the Andean region of Ecuador, and...
zoologia.pensoft.net 1867 was likewise described on the basis of a single specimen from Pará, nor... more zoologia.pensoft.net 1867 was likewise described on the basis of a single specimen from Pará, northern Brazil, but Etheridge (in Peters and Donoso-Barros 1970) referred it as a synonym of O. tricristatus. The former taxon remained poorly known until Cunha (1981) published a study based on several specimens from eastern Pará. Avila-Pires (1995), however, examining the holotypes of both species, demonstrated that these two taxa, by then referred to Stenocercus Duméril & Bibron, 1837 (Frost 1992), corresponded to distinct species. Taking into account where M. Claussen lived and traveled, Avila-Pires (1995) suggested that S. tricristatus probably would occur in Minas Gerais, southeastern Brazil. Torres-Carvajal (2007a), in a taxonomic revision of the genus, compared S. tricristatus with all other congeners and presented a description based on the literature and on data provided by R. Etheridge. During field trips to Serra da Canastra, Minas Gerais, six lizards were collected that at first we thought belonged to S. tricris tatus (Figs 2, 3). Considering that Nogueira and Rodrigues (2006) described two other species, S. quinarius Nogueira & Rodrigues, 2006 and S. squarrosus Nogueira & Rodrigues, 2006, from central and northeastern Brazil, with the characteristic pyramidal head and enlarged, dorsally projected post-supraciliaries present in S. dumerilii and S. tricristatus, we performed a comparison with these four species (from here on referred to as the 'horned Stenocercus'). Our data showed that, although the specimens from Serra da Canastra are most similar to S. tricristatus, they also show some significant differences and represent clearly a distinct species, described here. In order to facilitate comparisons, we also present a redescription of the holotype of S. tricristatus. MATERIAL AND METHODS Specimens were collected during field trips to Serra
The main objective of this study was to examine the natural history and the ecology of the specie... more The main objective of this study was to examine the natural history and the ecology of the species that constitute a snake assemblage in the Atlantic Rainforest, at Núcleo Picinguaba, Parque Estadual da Serra do Mar, located on the northern coast of the state of São Paulo, southeastern Brazil. The main aspects studied were: richness, relative abundance, daily and seasonal activity, and substrate use. We also provide additional information on natural history of the snakes. A total of 282 snakes, distributed over 24 species, belonging to 16 genera and four families, has been found within the area of the Núcleo Picinguaba. Species sampled more frequently were Bothrops jararaca and B. jararacussu. The methods that yielded the best results were time constrained search and opportunistic encounters. Among the abiotic factors analyzed, minimum temperature, followed by the mean temperature and the rainfall are apparently the most important in determining snake abundance. Most species present...
Feeding specialization is a recurrent issue in the evolution of snakes and is sometimes associate... more Feeding specialization is a recurrent issue in the evolution of snakes and is sometimes associated to morphological and/or behavioral adaptations that improve snake performance to exploit a particular food type. Despite its importance for animal fitness, the role of physiological traits has been much less studied than morphological and behavioral traits in the evolution of feeding specialization in snakes. In this context, the energetic cost of post-prandial period is an important physiological factor due to the remarkable effect on the snake energy budget. We collected data on post-prandial metabolic rate (SDA) in five species of pit vipers from the genus Bothrops with different degrees of mammal feeding specialization to test the hypothesis that feeding specialist species have lower energy costs during the digestion of their regular food item when compared to species with a more generalist diet. Our results support this hypothesis and suggest that ontogenetic changes in diet can b...
Should read: "SANTIAGO CASTROVIEJO-FISHER" NOTE: The ideas presented in this editorial do not int... more Should read: "SANTIAGO CASTROVIEJO-FISHER" NOTE: The ideas presented in this editorial do not intend to reflect the official position of the institution. The Brazilian Academy of Sciences is organizing a committee to analyze this issue in depth and in due time will present an official institutional position.
An increase in ecological opportunities, either through changes in the environment or acquisition... more An increase in ecological opportunities, either through changes in the environment or acquisition of new traits, is frequently associated with an increase in species and morphological diversification. However, it is possible that certain ecological settings might prevent lineages from diversifying. Arboreality evolved multiple times in vipers, making them ideal organisms for exploring how potentially new ecological opportunities affect their morphology and speciation regimes. Arboreal snakes are frequently suggested to have a very specialized morphology, and being too large, too small, too heavy, or having short tails might be challenging for them. Using trait-evolution models, we show that arboreal vipers are evolving towards intermediate body sizes, with longer tails and more slender bodies than terrestrial vipers. Arboreality strongly constrains body size and circumference evolution in vipers, while terrestrial lineages are evolving towards a broader range of morphological varian...
In this Article originally published, owing to a technical error, the author 'Laurent Chirio&... more In this Article originally published, owing to a technical error, the author 'Laurent Chirio' was mistakenly designated as a corresponding author in the HTML version, the PDF was correct. This error has now been corrected in the HTML version. Further, in Supplementary Table 3, the authors misspelt the surname of 'Danny Meirte'; this file has now been replaced.
The distributions of amphibians, birds and mammals have underpinned global and local conservation... more 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 sign...
The Brazilian Atlantic forest is a highly threatened biodiversity hotspot, harboring one of the h... more The Brazilian Atlantic forest is a highly threatened biodiversity hotspot, harboring one of the highest levels of amphibian species richness in the world. Amphibian conservation in Neotropical biomes is critical because freshwater ecosystems typically experience sharp declines in biodiversity before much is known about species that depend on those environments. Environmental DNA (eDNA) analysis is a new approach for monitoring aquatic organisms and provides valuable information on species occurrence in freshwater ecosystems. Here, we assess community diversity in Neotropical streams using eDNA metabarcoding. We compare data from a fiveyear traditional field survey with results from a short-term eDNA analysis in four streams of the Atlantic forest of southeastern Brazil. We recorded 19 species over 5 years using visual-acoustic methods, of which 10 species are associated with the streams during at least one life stage (egg, tadpole or post-metamorphic). We were able to detect nine of the latter species using eDNA metabarcoding from water samples collected over 4 days. Amphibian community composition as measured by both methods showed high similarity in three streams, but was not perfect, as eDNA failed to detect known species in a fourth stream. Furthermore, in one stream we detected through eDNA metabarcoding a species (Aplastodiscus eugenioi) found only once during the 5-year traditional survey in that stream. Also, three species (Cycloramphus boraceiensis, Hylodes asper, and Hylodes phyllodes) with the highest dependence on aquatic habitat showed the highest number of positive PCR detections on eDNA samples. Our results showed that eDNA metabarcoding can be a useful tool to assess community diversity in tropical streams, and although not perfect in detection, this method can potentially improve our ability to conserve Neotropical amphibians.
We describe a new species of hylid frog, Scinax peixotoi, from Queimada Grande Island, southeaste... more We describe a new species of hylid frog, Scinax peixotoi, from Queimada Grande Island, southeastern Brazil. The new species belongs to the Scinax perpusillus species group, in which all known forms inhabit bromeliads, and is diagnosed by the following set of characters: moderate-size (males 18.8–20.7 mm SVL, females 22.4–25.1 mm SVL); canthus rostralis distinct; dorsal skin slightly rugose; and a distinct advertisement call with relatively low dominant frequency. The new species is known from a single population on Queimada Grande, an island of 43 ha, approximately 33 km distant from the coast of São Paulo State, where it inhabits scattered patches of bromeliads. The highly specialized and patchy habitat of S. peixotoi, associated with its small range size, make this species highly susceptible to stochastic or anthropogenic habitat disturbances, which could lead it to extinction.
Understanding the geographical distribution and community composition of species is crucial to mo... more Understanding the geographical distribution and community composition of species is crucial to monitor species persistence and define effective conservation strategies. Environmental DNA (eDNA) has emerged as a powerful noninvasive tool for species detection. However, most eDNA survey methods have been developed and applied in temperate zones. We tested the feasibility of using eDNA to survey anurans in tropical streams in the Brazilian Atlantic forest and compared the results with short-term visual and audio surveys. We detected all nine species known to inhabit our focal streams with one single visit for eDNA sampling. We found a higher proportion of sequence reads and larger number of positive PCR replicates for more common species and for those with life cycles closely associated with the streams, factors that may contribute to increased release of DNA in the water. However, less common species were also detected in eDNA samples, demonstrating the detection power of this method....
Snakes of the cosmopolitan family Viperidae comprise around 329 venomous species showing a striki... more Snakes of the cosmopolitan family Viperidae comprise around 329 venomous species showing a striking heterogeneity in species richness among lineages. While the subfamily Azemiopinae comprises only two species, 70% of all viper species are arranged in the subfamily Crotalinae or the "pit vipers". The radiation of the pit vipers was marked by the evolution of the heat-sensing pits, which has been suggested to be a key innovation for the successful diversification of the group. Additionally, only crotalines were able to successfully colonize the New World. Here, we present the most complete molecular phylogeny for the family to date that comprises sequences from nuclear and mitochondrial genes representing 79% of all living vipers. We also investigated the time of divergence between lineages, using six fossils to calibrate the tree, and explored the hypothesis that crotalines have undergone an explosive radiation. Our phylogenetic analyses retrieved high support values for the monophyly of the family Viperidae, subfamilies Viperinae and Crotalinae, and 22 out of 27 genera, as well as well-supported intergeneric relationships throughout the family. We were able to recover a strongly supported sister clade to the New World pit vipers that comprises Gloydius, Ovophis, Protobothrops and Trimeresurus gracilis. Our results agree in many aspects with other studies focusing on phylogenetics of vipers, but we also recover new relationships as well. Despite the addition of new sequences we were not able to resolve some of the poor supported relationships previously suggested. Time of divergence estimates suggested that vipers started to radiate around the late Paleocene to middle Eocene with subfamilies most likely dating back to the Eocene. The invasion of the New World might have taken place sometime close to the Oligocene/Miocene boundary. Diversification analyses suggested a shift in speciation rates during the radiation of a sub-clade of pit vipers where speciation rates rapidly increased but slowed down toward the present. Thus, the evolution of the loreal pits alone does not seem to explain their explosive speciation rates. We suggest that climatic and geological changes in Asia and the invasion of the New World may have also contributed to the speciation shift found in vipers.
Life-history information constitutes the raw data for building population models used in species ... more Life-history information constitutes the raw data for building population models used in species conservation. We provide life-history data for the endangered Santa Catalina Island Rattlesnake, Crotalus catalinensis. We use data from 277 observations of C. catalinensis made between 2002 and 2011 on the island. Mean snout-vent length (SVL) of adult C. catalinensis was 643 mm for males and 631 mm for females; the difference was not significant. The degree of sexual size dimorphism (SSD; using SVL) was -0.02. However, sexes were dimorphic in total length (SVL + tail length), relative tail length, and stoutness. Juvenile recruitment occurs during late-summer. In their first year of life, juveniles seem to grow at a rate of about 1.7 cm/mo. Females seem to become mature around 570 mm SVL, probably in the year when they become 2 y old. Scattered literature data corroborates the time of juvenile recruitment described herein. Growth in C. catalinensis seems to be slower than that of C. rube...
The dipsadid snake genus Tropidodryas consists of two species that occur in the Atlantic Forest a... more The dipsadid snake genus Tropidodryas consists of two species that occur in the Atlantic Forest along Brazil's eastern coast, a conservation hot spot. Life-history information on pairs of sister species might allow insights into the evolutionary transitions that have occurred since the cladogenesis that putatively gave rise to them. We provide information on distribution, morphology, diet, reproduction, and seasonal activity of these species based on the examination of 624 specimens. The genus Tropidodryas occurs along a large extent of the Atlantic Forest of eastern Brazil, with T. striaticeps occurring at higher elevations, on average, than T. serra. These snakes forage by day either on the ground or in vegetation, consuming a wide variety of vertebrates, mainly mammals. Higher proportions of birds in the diet of T. serra and certain mammals in the diet of T. striaticeps probably reflect elevational differences in prey availability. An ontogenetic diet shift occurs in both species, with juveniles consuming mainly ectothermic prey (lizards and anurans), and adults preying predominantly on mammals. Caudal luring has been documented in juveniles, but the pale color and high frequency of injuries on the tail of larger individuals indicate that adult T. striaticeps also employ this technique to attract prey. Sexual dimorphism occurs in body size, tail size, and diameter of the eye. Female reproductive cycles are seasonal in both species, with egg laying occurring in warmer periods of the year. However, T. striaticeps seems to have a more extended reproductive cycle, with some females being able to lay eggs 1 or 2 mo earlier. Environmental differences between high and low altitudes in the Atlantic Forest are likely responsible for the slight ecological divergence between these two closely related snakes.
We studied the defensive strike of one species of each of five recognized lineages within the gen... more We studied the defensive strike of one species of each of five recognized lineages within the genus Bothrops, namely, B. alternatus, B. jararaca, B. jararacussu, B. moojeni and B. pauloensis. The defensive strike of the studied species was in general similar to that of Crotalus viridis and C. atrox, but some important differences were observed. Bothrops alternatus and B. pauloensis struck preferentially from a tight body posture, whereas B. jararaca and B. moojeni from a loose body posture. Defensive strikes were either true or false (during the latter, the mouth remains closed or partially open). Almost all strikes were successful; only on a few occasions snakes missed their target (flawed strikes). Strike variables were very conservative among the five species, especially strike distance and height, and one possible explanation may be related to constraints imposed on strike variables as a way of increasing strike accuracy.
The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is ... more The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is suggested to have acted as a dispersal barrier for terrestrial organisms by fragmenting a single large forest that existed in South America into the present Atlantic and Amazon forests. Here we tested the hypothesis that the expansion of the South American diagonal of open/dry landscapes acted as a vicariant process for forest lanceheads of the genus Bothrops, by analyzing the temporal range dynamics of those snakes. We estimated ancestral geographic ranges of the focal lancehead clade and its sister clade using a Bayesian dated phylogeny and the BioGeoBEARS package. We compared nine Maximum Likelihood models to infer ancestral range probabilities and their related biogeographic processes. The best fitting models (DECTS and DIVALIKETS) recovered the ancestor of our focal clade in the Amazon biogeographic region of northwestern South America. Vicariant processes in two different subclades...
Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being ... more Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being endemic to this ecoregion. However, the Atlantic forest is one of the most threatened tropical ecoregions, with only 16% of its original area remaining as forest. This extensive habitat loss must have had a negative effect on its snake fauna. Indeed, 53% of the threatened snakes of Brazil occur in the Atlantic forest. Therefore, basic natural history information that can potentially contribute to the conservation of Atlantic forest snakes are urgently needed. Here the natural history of a snake assemblage at Etá Farm region, Sete Barras municipality, south-eastern Brazil is described, and a visual guide and an identification key provided that can be used by researchers and local people to identify snakes from this region. Most of the species found in the field use both open areas and forests, are primarily terrestrial, present diurnal activity, and include frogs in their diet. A higher n...
We provide information on the diversity and natural history of anurans from preserved and disturb... more We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Etá Farm, municipality of Sete Barras, state of São Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Etá Farm is necessary to preserve the diverse amphibian fauna of this region.
Rare species tend to be especially sensitive to habitat disturbance, making them important conser... more Rare species tend to be especially sensitive to habitat disturbance, making them important conservation targets. Thus, rarity patterns might be an important guide to conservation efforts. Rabinowitz’s approach defines rarity using a combination of geographical range, habitat specificity, and local abundance, and is frequently used in conservation prioritization. Herein, we use Rabinowitz’s approach to classify the New World (NW) pitvipers (family Viperidae) regarding rarity. We tested whether body size and latitude could predict rarity, and we compared rarity patterns with extinction risk assessments and other prioritization methods in order to detect rare species not classified as threatened or prioritized. Most NW pitvipers have large geographical ranges, high local abundances, and narrow habitat breadths. There are 11.8% of NW pitviper species in the rarest category and they occur along the Pacific coast of Mexico, in southern Central America, in the Andean region of Ecuador, and...
zoologia.pensoft.net 1867 was likewise described on the basis of a single specimen from Pará, nor... more zoologia.pensoft.net 1867 was likewise described on the basis of a single specimen from Pará, northern Brazil, but Etheridge (in Peters and Donoso-Barros 1970) referred it as a synonym of O. tricristatus. The former taxon remained poorly known until Cunha (1981) published a study based on several specimens from eastern Pará. Avila-Pires (1995), however, examining the holotypes of both species, demonstrated that these two taxa, by then referred to Stenocercus Duméril & Bibron, 1837 (Frost 1992), corresponded to distinct species. Taking into account where M. Claussen lived and traveled, Avila-Pires (1995) suggested that S. tricristatus probably would occur in Minas Gerais, southeastern Brazil. Torres-Carvajal (2007a), in a taxonomic revision of the genus, compared S. tricristatus with all other congeners and presented a description based on the literature and on data provided by R. Etheridge. During field trips to Serra da Canastra, Minas Gerais, six lizards were collected that at first we thought belonged to S. tricris tatus (Figs 2, 3). Considering that Nogueira and Rodrigues (2006) described two other species, S. quinarius Nogueira & Rodrigues, 2006 and S. squarrosus Nogueira & Rodrigues, 2006, from central and northeastern Brazil, with the characteristic pyramidal head and enlarged, dorsally projected post-supraciliaries present in S. dumerilii and S. tricristatus, we performed a comparison with these four species (from here on referred to as the 'horned Stenocercus'). Our data showed that, although the specimens from Serra da Canastra are most similar to S. tricristatus, they also show some significant differences and represent clearly a distinct species, described here. In order to facilitate comparisons, we also present a redescription of the holotype of S. tricristatus. MATERIAL AND METHODS Specimens were collected during field trips to Serra
The main objective of this study was to examine the natural history and the ecology of the specie... more The main objective of this study was to examine the natural history and the ecology of the species that constitute a snake assemblage in the Atlantic Rainforest, at Núcleo Picinguaba, Parque Estadual da Serra do Mar, located on the northern coast of the state of São Paulo, southeastern Brazil. The main aspects studied were: richness, relative abundance, daily and seasonal activity, and substrate use. We also provide additional information on natural history of the snakes. A total of 282 snakes, distributed over 24 species, belonging to 16 genera and four families, has been found within the area of the Núcleo Picinguaba. Species sampled more frequently were Bothrops jararaca and B. jararacussu. The methods that yielded the best results were time constrained search and opportunistic encounters. Among the abiotic factors analyzed, minimum temperature, followed by the mean temperature and the rainfall are apparently the most important in determining snake abundance. Most species present...
Feeding specialization is a recurrent issue in the evolution of snakes and is sometimes associate... more Feeding specialization is a recurrent issue in the evolution of snakes and is sometimes associated to morphological and/or behavioral adaptations that improve snake performance to exploit a particular food type. Despite its importance for animal fitness, the role of physiological traits has been much less studied than morphological and behavioral traits in the evolution of feeding specialization in snakes. In this context, the energetic cost of post-prandial period is an important physiological factor due to the remarkable effect on the snake energy budget. We collected data on post-prandial metabolic rate (SDA) in five species of pit vipers from the genus Bothrops with different degrees of mammal feeding specialization to test the hypothesis that feeding specialist species have lower energy costs during the digestion of their regular food item when compared to species with a more generalist diet. Our results support this hypothesis and suggest that ontogenetic changes in diet can b...
Should read: "SANTIAGO CASTROVIEJO-FISHER" NOTE: The ideas presented in this editorial do not int... more Should read: "SANTIAGO CASTROVIEJO-FISHER" NOTE: The ideas presented in this editorial do not intend to reflect the official position of the institution. The Brazilian Academy of Sciences is organizing a committee to analyze this issue in depth and in due time will present an official institutional position.
An increase in ecological opportunities, either through changes in the environment or acquisition... more An increase in ecological opportunities, either through changes in the environment or acquisition of new traits, is frequently associated with an increase in species and morphological diversification. However, it is possible that certain ecological settings might prevent lineages from diversifying. Arboreality evolved multiple times in vipers, making them ideal organisms for exploring how potentially new ecological opportunities affect their morphology and speciation regimes. Arboreal snakes are frequently suggested to have a very specialized morphology, and being too large, too small, too heavy, or having short tails might be challenging for them. Using trait-evolution models, we show that arboreal vipers are evolving towards intermediate body sizes, with longer tails and more slender bodies than terrestrial vipers. Arboreality strongly constrains body size and circumference evolution in vipers, while terrestrial lineages are evolving towards a broader range of morphological varian...
In this Article originally published, owing to a technical error, the author 'Laurent Chirio&... more In this Article originally published, owing to a technical error, the author 'Laurent Chirio' was mistakenly designated as a corresponding author in the HTML version, the PDF was correct. This error has now been corrected in the HTML version. Further, in Supplementary Table 3, the authors misspelt the surname of 'Danny Meirte'; this file has now been replaced.
The distributions of amphibians, birds and mammals have underpinned global and local conservation... more 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 sign...
The Brazilian Atlantic forest is a highly threatened biodiversity hotspot, harboring one of the h... more The Brazilian Atlantic forest is a highly threatened biodiversity hotspot, harboring one of the highest levels of amphibian species richness in the world. Amphibian conservation in Neotropical biomes is critical because freshwater ecosystems typically experience sharp declines in biodiversity before much is known about species that depend on those environments. Environmental DNA (eDNA) analysis is a new approach for monitoring aquatic organisms and provides valuable information on species occurrence in freshwater ecosystems. Here, we assess community diversity in Neotropical streams using eDNA metabarcoding. We compare data from a fiveyear traditional field survey with results from a short-term eDNA analysis in four streams of the Atlantic forest of southeastern Brazil. We recorded 19 species over 5 years using visual-acoustic methods, of which 10 species are associated with the streams during at least one life stage (egg, tadpole or post-metamorphic). We were able to detect nine of the latter species using eDNA metabarcoding from water samples collected over 4 days. Amphibian community composition as measured by both methods showed high similarity in three streams, but was not perfect, as eDNA failed to detect known species in a fourth stream. Furthermore, in one stream we detected through eDNA metabarcoding a species (Aplastodiscus eugenioi) found only once during the 5-year traditional survey in that stream. Also, three species (Cycloramphus boraceiensis, Hylodes asper, and Hylodes phyllodes) with the highest dependence on aquatic habitat showed the highest number of positive PCR detections on eDNA samples. Our results showed that eDNA metabarcoding can be a useful tool to assess community diversity in tropical streams, and although not perfect in detection, this method can potentially improve our ability to conserve Neotropical amphibians.
We describe a new species of hylid frog, Scinax peixotoi, from Queimada Grande Island, southeaste... more We describe a new species of hylid frog, Scinax peixotoi, from Queimada Grande Island, southeastern Brazil. The new species belongs to the Scinax perpusillus species group, in which all known forms inhabit bromeliads, and is diagnosed by the following set of characters: moderate-size (males 18.8–20.7 mm SVL, females 22.4–25.1 mm SVL); canthus rostralis distinct; dorsal skin slightly rugose; and a distinct advertisement call with relatively low dominant frequency. The new species is known from a single population on Queimada Grande, an island of 43 ha, approximately 33 km distant from the coast of São Paulo State, where it inhabits scattered patches of bromeliads. The highly specialized and patchy habitat of S. peixotoi, associated with its small range size, make this species highly susceptible to stochastic or anthropogenic habitat disturbances, which could lead it to extinction.
Understanding the geographical distribution and community composition of species is crucial to mo... more Understanding the geographical distribution and community composition of species is crucial to monitor species persistence and define effective conservation strategies. Environmental DNA (eDNA) has emerged as a powerful noninvasive tool for species detection. However, most eDNA survey methods have been developed and applied in temperate zones. We tested the feasibility of using eDNA to survey anurans in tropical streams in the Brazilian Atlantic forest and compared the results with short-term visual and audio surveys. We detected all nine species known to inhabit our focal streams with one single visit for eDNA sampling. We found a higher proportion of sequence reads and larger number of positive PCR replicates for more common species and for those with life cycles closely associated with the streams, factors that may contribute to increased release of DNA in the water. However, less common species were also detected in eDNA samples, demonstrating the detection power of this method....
Snakes of the cosmopolitan family Viperidae comprise around 329 venomous species showing a striki... more Snakes of the cosmopolitan family Viperidae comprise around 329 venomous species showing a striking heterogeneity in species richness among lineages. While the subfamily Azemiopinae comprises only two species, 70% of all viper species are arranged in the subfamily Crotalinae or the "pit vipers". The radiation of the pit vipers was marked by the evolution of the heat-sensing pits, which has been suggested to be a key innovation for the successful diversification of the group. Additionally, only crotalines were able to successfully colonize the New World. Here, we present the most complete molecular phylogeny for the family to date that comprises sequences from nuclear and mitochondrial genes representing 79% of all living vipers. We also investigated the time of divergence between lineages, using six fossils to calibrate the tree, and explored the hypothesis that crotalines have undergone an explosive radiation. Our phylogenetic analyses retrieved high support values for the monophyly of the family Viperidae, subfamilies Viperinae and Crotalinae, and 22 out of 27 genera, as well as well-supported intergeneric relationships throughout the family. We were able to recover a strongly supported sister clade to the New World pit vipers that comprises Gloydius, Ovophis, Protobothrops and Trimeresurus gracilis. Our results agree in many aspects with other studies focusing on phylogenetics of vipers, but we also recover new relationships as well. Despite the addition of new sequences we were not able to resolve some of the poor supported relationships previously suggested. Time of divergence estimates suggested that vipers started to radiate around the late Paleocene to middle Eocene with subfamilies most likely dating back to the Eocene. The invasion of the New World might have taken place sometime close to the Oligocene/Miocene boundary. Diversification analyses suggested a shift in speciation rates during the radiation of a sub-clade of pit vipers where speciation rates rapidly increased but slowed down toward the present. Thus, the evolution of the loreal pits alone does not seem to explain their explosive speciation rates. We suggest that climatic and geological changes in Asia and the invasion of the New World may have also contributed to the speciation shift found in vipers.
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Papers by Marcio Martins