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The selection of appropriate calling sites is a key aspect in the reproductive strategy of nearly all anurans. We evaluated if males of the South American tree frog (Hypsiboas pulchellus) select calling sites in undisturbed subtropical wetlands based on specific habitat cues. The study was designed to represent a snapshot of the male calling activity under low densities of intra- and interspecific competitors and little variation of climatic conditions. We characterized calling sites by measuring the vegetation attributes and flood levels of calling sites occupied by 59 males and comparing them to available microhabitats. We found that males exhibit some degree of selectivity for calling sites, often selecting microhabitats with greater density of vegetation < 50 cm tall. Calling site selection was not affected by water depth or area flooded. Most individuals vocalized in sites near the ground (≤ 25 cm), a pattern that is the contrary to that expected to maximize sound propagation. We suggest that, due to the open habitat of the studied area, the choice of calling sites is more related to the need for shelter from predation and avoidance of desiccation and heat loss than to bioacoustic performance.
Since 1965, Amphisbaena leucocephalaPeters, 1878 has been considered species inquirenda due to overlap in meristic data between it and A. pretrei and the the low number of specimens available for analysis. Herein, based on recently collected specimens, we review its taxonomic status through morphological and genetic data. Both analyses recovered A. leucocephala as a distinct species, sister to, but widely divergent from, A. pretrei. It is characterized by having 10–13 precloacal pores, 231–246 body annuli, 25–29 caudal annuli, autotomy site at the 6th–8th caudal annulus, 17–22 dorsal, and 20–23 ventral segments at midbody.
Caimans (Crocodilia: Alligatoridae) are top-level predators in aquatic ecosystems of the Neotropics. This paper presents data on the diet of caimans from the Peruvian Amazon (principally Paleosuchus spp., but also Caiman crocodilus and Melanosuchus niger), including feeding observations and stomach content examinations. A total of 58 stomach content analyses and three in situ feeding observations were made, and incidence of gastric parasitism and external injury were also studied. Insects, crustaceans, and fish were the most frequently encountered prey in the gut of P. trigonatus, but reptiles, fish, crustaceans, and mammals composed the greatest proportion of the diet by stomach content dry mass. We report novel squamate and fish species in the diet of Amazonian caimans and overall dietary findings consistent with that of other caiman diet literature. Gastroliths were absent from C. crocodilus and M. niger, although 44% of P. trigonatus sampled contained gastroliths. Parasitic nematodes were recovered from just under half of sampled C. crocodilus and P. trigonatus and 71% of M. niger. Injury rates were low in M. niger and P. trigonatus (< 10% of individuals) while 35% of C. crocodilus were injured, most often through damage to the tail. These data on caiman diet, gut parasitism, and injury rates help provide a baseline for comparison between species and study populations.
Anthropogenic effects on ecosystems are one of the main causes of reduction in the planet's biodiversity. The present study aimed to assess the effect of habitat disturbance on the body condition of the Colombian endemic lizard Anolis antonii. Two populations from the department of Tolima (Colombia) were chosen for this work, one located in a secondary forest and the other in an agricultural area. Between January–June 2014, visual encounter surveys were simultaneously performed from 7:00–18:00 h in both habitats. Individuals were captured manually and sex, snout-vent length (SVL) and body mass (BM) were recorded for each. The Body Condition Index (BCI) was calculated from the residuals of the linear regression between BM and SVL, which was compared between the two populations (60 adults in the secondary forest and 52 in the agricultural area). No significant variation in SVL or BM was recorded in the inter- and intra-population comparisons, but the BM of lizards was closely related to SVL and the BCI of the population from the agricultural area was significantly lower than that of the secondary forest population. These results indicate that habitat disturbance as a consequence of agricultural practices has a negative impact on the body condition of A. antonii, which could reduce its abilities to compete and survive.
Atractus potschi was described based on 12 specimens from the Brazilian states of Alagoas and Sergipe, and later knowledge of its morphological variation (meristic, morphometric, and color pattern data) was augmented on the basis of nine additional individuals from additional localities in northeastern Brazil. Based on the examination of collections and fieldwork, we found more than 70 additional specimens of Atractus potschi, 60 of them obtained during a single collecting event. In this paper, we report new data on intra-population morphological variation (external morphology, hemipenis, osteology, cephalic glands, and soft anatomy) and natural history for the species. We associate the variation displayed in some characters with sex or age. We relate most of the variation observed in the shape of the hemipenis with preparation artifacts at the moment of preserving specimens. Our results reveal a high level of population polychromatism, supplanting the geographical variability exhibited by this system, while other complexes of morphological characters are relatively conserved both within and among populations. Although this polychromatic pattern seems to be retained in several lineages of Atractus, this phenomenon might be related to distinct life history constrains of the species. On the basis of anecdoctal field data, we discuss the possibility of post-parturition aggregation of juveniles in Atractus potschi. Despite being based on a single observation, this report is significant, since such post-birth interactions in nature (other than reproductive ones) have only been documented previously in temperate regions.
Neotropical poison frogs (Dendrobatidae) display complex social behaviors. We studied home range behavior in Ameerega trivittata in the rainy season of two consecutive years at Panguana, Peru. Minimum convex polygon (MCP) and Kernel methods were employed. For the first time in the genus Ameerega, we found that females also occupied home ranges. Home range size in both sexes varied greatly and overlap was commonly found between and between sexes. Only a few specimens (both sexes) were rediscovered in the second rainy season, but always within the home range of the previous year. This finding suggests strong site fidelity but also a high seasonal turnover, which could be an indication of dispersal propensity. Maintenance and size of home ranges in males might be linked to individual fitness and the monopolization of resources (i.e., habitat structures) related to mating. Female home range behavior remains to be explained.
Introduced species are major drivers of biodiversity loss worldwide. Several squamate taxa have become established outside of their native ranges after human-mediated transportation, becoming a conservation concern. We report on the occurrence of an exotic anole lizard in the Baixada Santista region in coastal Brazil. To clarify the species' identity and examine the geographic source of its introduction, we generated sequences of one mitochondrial DNA marker. The anole is genetically closest to species in the Anolis carolinensis group (Dactyloidae), which does not occur naturally in South America. Phylogenetic analyses found that samples from Brazil nest within A. porcatus, a Cuban species that has also been introduced into Florida and the Dominican Republic. Results indicate that Brazilian A. porcatus are nested among samples from La Habana, Matanzas, and Pinar del Río, which may suggest a western Cuban source of introduction. Nevertheless, Brazilian samples also cluster closely with a sample from Florida, which may suggest that the Brazilian population originated from lizards exotic elsewhere. High densities of adults and juveniles suggest that it comprises a well-established reproductive population in Brazil, thriving in urban and industrial areas. Introduction of A. porcatus may be related to the presence of a major seaport in the study region. Further assessments are needed to uncover whether this species will be able to expand into the surrounding Atlantic Rainforest, and whether it will impact the local communities, including native anoles. This study demonstrates the usefulness of molecular approaches for proper species identification in a group of aggressive invaders characterized by morphological conservatism, hybridization, and convoluted taxonomy.
Jamaican boas (Chilabothrus subflavus) are a United States-listed Foreign Endangered Species and a Jamaican-protected species whose numbers and distribution have substantially declined. Because much of the literature pertaining to Jamaican boa distribution is based almost entirely on anecdotal evidence, we developed the most up-to-date distributional map of Jamaican boas on the island, which incorporate all previous findings and additional published reports of this species. To further assess general habitat requirements of existing Jamaican boa populations, we conducted a habitat availability and use analysis for this species. Of the 21 habitat types delineated by the Jamaica Forestry Department, we found that Jamaican boas used only five of the 21 habitat types in greater proportion to their availability. Jamaican boas used forested areas in greater proportion than any other habitat type and underused areas with anthropogenic alterations. Our distribution and general habitat use analysis also shows that cumulatively, less than 10% of the total land area of Jamaica may constitute useable Jamaican boa habitat, therefore, we recommend a multipronged species survival plan coupled with reforestation strategies be implemented in order to sustain remaining populations of Jamaica's largest native terrestrial predator.
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