Crocodilians are a taxonomic group of large predators with important ecological and evolutionary benefits for ecosystem functioning in the face of global change. Anthropogenic actions affect ...negatively crocodilians' survival and more than half of the species are threatened with extinction worldwide. Here, we map and explore three dimensions of crocodilian diversity on a global scale. To highlight the ecological importance of crocodilians, we correlate the spatial distribution of species with the ecosystem services of nutrient retention in the world. We calculate the effectiveness of global protected networks in safeguarding crocodilian species and provide three prioritization models for conservation planning. Our results show the main hotspots of ecological and evolutionary values are in southern North, Central and South America, west-central Africa, northeastern India, and southeastern Asia. African species have the highest correlation to nutrient retention patterns. Twenty-five percent of the world's crocodilian species are not significantly represented in the existing protected area networks. The most alarming cases are reported in northeastern India, eastern China, and west-central Africa, which include threatened species with low or non-significant representation in the protected area networks. Our highest conservation prioritization model targets southern North America, east-central Central America, northern South America, west-central Africa, northeastern India, eastern China, southern Laos, Cambodia, and some points in southeastern Asia. Our research provides a global prioritization scheme to protect multiple dimensions of crocodilian diversity for achieving effective conservation outcomes.
The Atlantic Forest is one of the largest and richest tropical rainforests on the planet, being one of the 25 world priorities for conservation. The Atlantic Forest portion located north of the São ...Francisco River corresponds to the Pernambuco Endemism Center (PEC). We describe the snake composition of the PEC, providing information about the diversity, natural history and geographical distribution of the species, based on records from five scientific collections and additional information from the literature. A total of 78 species of snakes distributed in eight families was registered in the Pernambuco Endemism Center. The Caatinga is the Brazilian biome that most shares species with the PEC, followed by Cerrado. On the other hand, seven species are considered endemic of this region. Most of the snake species in the PEC have been registered in forest (94.8%), followed by "Brejos Nordestinos" (46.1%), Tabuleiros (43.5%), Restingas (14.1%) and Mangroves (5.1%). The PEC snake fauna includes mainly terrestrial species (60.2%) and cryptozoic and/or fossorial species (21.7%), but also presents a high richness of semi-arboreal and arboreal species (29.5%). Vertebrates are the main food item consumed by the species (78% of species), among the main prey are mammals, lizards, and amphibians. Most species show a strictly nocturnal activity period (50%), followed by strictly diurnal (38%). The PEC is the most degraded and least known region of the Atlantic Forest, yet it has revealed a high richness of snake species, including seven endemic species. It is emphasized that regional conservation efforts need to be intensified, because few forests in the region are formally protected, and the majority consist of small and poorly protected fragments, which means that many species in the region may be in risk of extinction.
Despite an increase in studies focusing on snake ecology and composition in the northeastern Atlantic Forest, several poorly studied sites and environments remain. The aim of this study was to assess ...species richness and natural history attributes of the snakes of an assemblage in the Restinga, Tabuleiro and Forest environments of the Atlantic Forest of the south coast of Paraíba, northeastern Brazil. A total of 151 individuals of 27 species, 23 genera, and six families of snakes were found. The most effective sampling methods were time-constrained searches and incidental encounters. Species sampled most frequently were the blindsnake
, the Boa Constrictor
, the Brown Vinesnake
, and the Brazilian False Coral Snake
. The snake fauna is characterized mainly by terrestrial species found in open-area environments of Restinga and Tabuleiro, and with most species feeding on amphibians and small mammals. The rarefaction curve did not reach the asymptote and new species should be recorded for south coast of Paraíba in future studies. Despite the richness and composition of snakes of the south coast being similar to other areas in the state, there is a lack of some species typically linked to forests, and this is probably because of the high level of deforestation that the south area of the state has suffered.
Due to the high level of disturbance in natural ecosystems and the progressive loss of habitats resulting from anthropic occupation, biodiversity conservation represents one of the greatest ...challenges today. Red lists of threatened species are essential tools for identifying species at risk of extinction and guiding conservation efforts. In this study, we assessed the vulnerability to extinction of 55 snake species that occur in the Atlantic Forest of northeastern Brazil in Paraíba state. We developed vulnerability indices based on 12 factors known to influence the survival of snake populations. To analyze the threat profiles and relative risk levels within the snake community, we employed principal component analysis (PCA) and cluster analysis. Additionally, we compared our findings with existing red lists of threatened species. Our results reveal that only 18% of the snake fauna in this region is free of any threat. The aquatic species
Helicops angulatus
and
Oxyrhopus trigeminus
were the snakes that presented the lowest risk of extinction, while
Caaeteboia gaeli
and
Crotalus durissus
presented the highest risk of extinction. Two groups of species were considered non-threatened and five groups were considered threatened. Our study provides the first overview on the conservation status of snake species in the northern portion of the Atlantic Forest and contributes to a better evaluation of conservation planning for this group in the region.
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.
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.
One key strategy to publicise the benefits of nature more effectively to people is to correlate indicators of human well-being with conservation needs. Turtles are important and publicly visible ...ecological indicator groups. We use continental turtles as flagship umbrella species in the Brazilian Atlantic Forest hotspot to design a conservation strategy that incorporates taxonomic (TD), functional (FD) and phylogenetic diversity (PD) for improved cost-effective outcomes. We first analyse the effectiveness of the current arrangement of protected areas (PAs) in safeguarding species by calculating the mean percentage overlap of each species range and the PAs network. We create three conservation models that differ in the amount of TD, FD and PD preserved. Each model defines a distinct plan (and cost) of paying landowners to participate in set-aside programs to preserve local habitats. We also analyse the performance of indicator species in representing TD, FD and PD gains and economic costs induced by payments for ecosystem services. The results show that species of continental turtles are not well conserved in the PAs. The spatial distribution of TD is highly correlated with that of FD and PD in the biome, with high values in the central region, in the extreme North, and in the South of the Atlantic Forest, due to the co-existence of the evolutionary lineages. We suggest a program for conservation planning to protect a threatened biodiversity hotspot, the ecosystem functions provided by flagship umbrella species, and its associated ecological and evolutionary values. Our findings are providing a representation of ecological and evolutionary values of continental turtles with annual economic benefits from environmental management tools.
The Cerrado is one of the richest tropical savannas and is considered a biodiversity “hotspot.” It is estimated that, at the current rate of loss, the ecosystem will disappear by the year 2030. The ...number of new species being discovered in the Cerrado has increased linearly, especially over the last 50 years. We describe a new species of Cnemidophorus from the Jalapão region, in the northern Cerrado biome, Brazil. Linear discriminant analyses and a naïve Bayesian model indicated that a combination of meristic counts (femoral pores, scales around tail, prefemorals, dorsals, and supralabials) and categorical variables derived from pholidosis and coloration clearly distinguish the new species from its congeners. The new species is apparently parapatric with C. mumbuca, the two species occurring on opposite banks of the Novo River. The two species are ecologically and morphologically similar, sharing a small body size, a fixed clutch size of a single egg, and a small number of femoral pores. The new species is apparently endemic to the Jalapão region, in the northern portion of the Cerrado biome. Its small size and restricted geographic range are consistent with findings from Cerrado anurans that undescribed species tend to be small and have reduced ranges. These results highlight the urgency of biotic surveys in Cerrado in face of its accelerated pace of destruction.
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