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The Andes Mountains of South America are considered one of the most biologically diverse and threatened areas in the world. Habitat destruction in this area is among the most common causes of amphibian population declines and extinction, but few studies have used complementary approaches to understand the interplay between habitat transformation and microhabitat use by amphibians. We studied the anuran diversity in modified vegetation cover types in a cloud forest in the tropical Andes of Colombia in order to compare components of biological diversity and microhabitat preferences among forested and human-altered habitats. Secondary Forest and Riparian Forest were the vegetation cover type with the highest local diversity, whereas the highest turnover was between the forested and human-altered areas. The species in the assemblage showed specific microhabitat associations with the substrate and the vertical stratification, with lower mean values of niche overlap between species pairs in forested area than in human altered areas. These results show how anthropic intervention creates less favorable vegetation cover types for some species of anurans and the way in which preferences for a specific micro-habitat could influence distribution in these vegetation cover type.
We analyzed the diet of Amphisbaena heathi, a species with restricted geographic distribution in northeastern Brazil. We also present data on morphometric and meristic characters of the examined specimens and update the geographic distribution of the species. The diet analysis was based on the contents of the digestive tract of 21 specimens collected in two urban Atlantic Forest fragments in Natal municipality, Rio Grande do Norte state, from 2008–2010. We collected 80.1% of the specimens near the surface (depth of ca. 3–5 cm) in moist earth under the leaf litter and 19.9% underground (ca. 15 cm beneath the surface). In total, we identified 60 prey items in the digestive tracts of A. heathi. The most important prey categories were ants, insect larvae, and cockroach nymphs. Ants predominated in frequency and number, while insect larvae and cockroaches predominated in volume. Besides insects, A. heathi also consumed earthworms, leeches, and centipedes. Considering our sample (n = 34) and the type series (n = 2), we modify some diagnostic characters of A. heathi: (1) 56.5–136 mm SVL; (2) 8.9–21.8 mm tail length; (3) 182–201 body annuli; (4) 23–28 tail annuli; (5) autotomic site at 7–9th caudal annuli; (6) 11–12 dorsal segments and 18–20 ventral segments per midbody annulus. Based on the minimum convex polygon method, we estimated the extent of occurrence of the species to be approximately 4278.7 km2 in the northeast portion of Rio Grande do Norte state.
We describe the advertisement call of Proceratophrys pombali and provide data on its distribution and natural history in Núcleo Curucutu, Parque Estadual da Serra do Mar, Itanhaém, São Paulo, Brazil, and Mongaguá, São Paulo, Brazil. Additionally, we specify the precise location of the type locality and detail the environments where the species occurs. The advertisement call is composed of a single, multipulsed note, and its dominant frequency is the highest recorded for the P. appendiculata complex. The species has explosive reproduction and its distribution restricted to the central region of the Serra do Mar of the state of São Paulo.
Although the feeding ecology of sympatric anurans has been studied, less is known about the food habits of co-occurring invasive and native frog species, particularly in the Neotropics. We compared the food habits of invasive bullfrogs (Lithobates catesbeianus) and native thin-toed frogs (Leptodactylus cf. latrans) in a locality of Southeastern Brazil. Monthly field surveys and stomach content analyses were performed between September 2008–April 2009 and September–November 2009. Prey items were identified to the lowest taxonomic level and diet overlap was estimated. Juveniles of both species had similar body sizes, but adult thin-toed frogs were smaller than adult bullfrogs. Insects and spiders dominated the diets of juveniles of both species and of adult thin-toed frogs, whereas anurans and water bugs predominated in adult bullfrog diets. Thin-toed frogs consumed a larger number of prey items than bullfrogs, which in turn consumed more voluminous prey items. Aquatic and amphibious prey items were more common in bullfrog diets. Adult thin-toed frogs preyed on juvenile bullfrogs, although the opposite was not observed. Diet overlap of equivalent age groups varied from low to intermediate between species. Our results showed that that dietary differences may be one of the factors allowing the coexistence of both species at the studied area, although not excluding possible negative impacts on native thin-toed frogs because of the presence of invasive bullfrogs.
Protected areas (PAs) cover a small proportion of the Earth's surface and most species are not covered by the current network. Amphibians are the least represented group in PAs around the world and expanding the network is still the major recommendation for species conservation. We evaluated the effectiveness of PAs in safeguarding endemic amphibians in the Cerrado biome of Minas Gerais state, southeastern Brazil. We conducted a gap analysis to highlight site-based conservation actions for target species within study site. We extracted occurrence points from the national database and calculated the intersection between the minimum convex polygon and natural vegetation remnants for each species. For each target species, we calculated the percentage of the range covered by PAs and assessed the scientific knowledge based on academic publications between 1950–2015. We recorded 206 amphibians in Minas Gerais, of which 127 occur in the Cerrado. We identified 24 target species and concluded that 80% are insufficiently protected by the current PA network. A quarter of the species have zero coverage and most species have < 30% of their range legally protected. In southwestern Minas Gerais, we recommend habitat restoration and connectivity to provide additional habitat to target species. In western Minas Gerais, the creation of PA seems to be the best solution. The distribution of target species is concentrated in the Espinhaço Mountain Range, where we recommend the establishment of biodiversity corridors. We examined 246 publications, most of which focus on taxonomy. Few species have sufficient information to have their conservation status re-assessed, with only 26.8% of publications containing specific information on conservation. Scientific knowledge must be improved for all research areas, especially species distributions and ecology, to support evidence-based conservation and management actions.
We present results obtained from the record of 156 snake specimens belonging to 42 species, that were run over in a 50 km stretch of paved roads located in the Geólogo Pedro de Moura Operational Base in the Urucu oil field, municipality of Coari, state of Amazonas, Brazil. Of the total specimens collected, 61.54% belong to primarily terrestrial species, 16.03% are primarily arboreal, 10.89% are semi-arboreal, 7.69% are fossorial, and one specimen (0.64%) is aquatic. Just over half (57.05%) of the specimens are diurnal, 25.64% are nocturnal, and 12.82% are cathemeral. The vast majority (96%) of snakes were > 200 mm snout—vent length. Aggregation zones were identified in localities where vehicle traffic is more intense, indicating that the highways are characterized as true physical barriers. We suggest that a collective effort is necessary to bring to light the ecological importance of snakes in the environment by conducting environmental education practices and trying to eliminate the myth that all snakes are dangerous to humans. Moreover, these practices should be applied jointly with programs that reduce speed on the roads, which can reduce the number of snake road-kills.
We investigated the gross anatomy, histology and ultrastructure of Duvernoy's glands and scanning electron microscopy of maxillary teeth of Helicops modestus, as well as its prey-handling behavior in laboratory. We later compared this histology with other species of Hydropsini. Duvernoy's glands are located in the post-ocular region, immediately behind the supralabial gland. Each gland is connected to a pair of ungrooved rear fangs by a vestibule from which the secretion is drained. Histological analysis showed that the gland is wrapped by a layer of connective tissue and consists of a glandular body formed by prismatic cells organized in acini and a duct lined with columnar cells. The prismatic cells are positive to PAS and bromophenol blue, indicating glycoprotein content, whereas the columnar ductal cells are positive to PAS and alcian blue pH 2.5, indicating the presence of acid mucous. Transmission electron microscopy showed electron-dense, heterogeneous granules in the prismatic cells, whereas the granules of the columnar cells were electron-luscent and homogeneous. The Duvernoy's glands of H. modestus are more similar to those of H. angulatus than any other species analyzed. Observations of prey-handling behavior showed that H. modestus strikes and holds fish in its mouth while repeatedly carrying out bilateral raking motions with both maxillae. Ingestion starts headfirst. We observed only a single episode of constriction. Snakes usually swallowed fish alive but clearly immobilized, suggesting that the primary function of the Duvernoy's secretion is associated with the quiescence/immobilization of the fish prey.
We describe a new species of Dendropsophus (Anura: Hylidae: Hylinae: Dendropsophini) from the Amazon river (= Rio Amazonas) basin, state of Amazonas, northern Brazil. The new taxon is included in the D. leucophyllatus group based on its phylogenetic position and on the presence of a pair of pectoral glands (a likely synapomorphy of the group). The species is distinguished from other species in the group by its color pattern and the morphology of hand and feet tubercles. In order to assess the phylogenetic relationships of the new taxon, we compiled a dataset including mitochondrial and nuclear DNA sequence data for all but one species in the D. leucophyllatus group, plus a series of hylid outgroups. A tree-alignment (direct optimization) parsimony analysis firmly support the new species as the sister taxon of D. sarayacuensis. The monophyly of the D. leucophyllatus species group is not recovered in our analysis and the issue is discussed further.
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