Some lizard species modulate the use of a retreat site based on the presence of scents from other individuals, behavior that requires scent recognition. Here, we investigated if two congeneric and syntopic lizards (adults of Liolaemus coeruleus and juveniles of L. ceii, which can be found sharing retreat sites in the wild) discriminate scents from each other during the pre-hibernation period. If the presence of heterospecific scents modulates sharing retreat sites, species would discriminate each other's scents. Lizards were individually exposed to four treatments, which were enclosures with scents of (1) from the focal individual (own); (2) a conspecific of the same sex as the focal lizard; (3) a heterospecific of the same sex as the focal lizard; and (4) a control (i.e., enclosure with a clean substrate). Our results suggest that there is no heterospecific recognition. This finding was not due to an inability to chemo-assess scents, since both species exhibited self-recognition (recognition of their own scents) and juveniles of L. ceii also showed conspecific recognition. Although it might be advantageous for species to share retreat sites, chemical recognition of heterospecific scents does not modulate this behavior in these syntopic species.

Acoustic communication is essential for reproductive success in frogs. Males produce different types of calls to attract females, advertise territoriality or location in a chorus, or communicate with heterospecifics. Quantitative descriptions of amphibian calls provide basic information for taxonomic, ecological, evolutionary, and conservation studies. Here, we describe the acoustic repertoire of Agalychnis spurrelli and discuss this species' reproductive behavior on the basis of observations made over the course of a breeding season in May–December 2007. Males produced one type of advertisement call and two types of aggressive calls (calls A and B) that differed in temporal and spectral frequency. The advertisement call was a single note. Aggressive call A was a long-pulsed single note, and call B was composed of more than two notes per call. Calling behavior was influenced by chorus size and male-to-male proximity, with males altering their advertisement calls with the increase of chorus size and eventually producing aggressive calls. These results suggest that A. spurrelli might exhibit graded aggressive signaling, helping males to delimit their calling site and reducing the number of agonistic encounters.

Given the increasing use of sympatric species to investigate niche differentiation and resource partition in biological communities, our study analyzes diet composition differences and trophic niche overlap between the sympatric species Physalaemus cuvieri and P. atim in the municipalities of Silvânia and Leopoldo Bulhões, Brazil. We used stomach flushing to obtain stomach contents from each individual and identified 11 prey categories for P. cuvieri and 17 for P. atim. Isoptera had the highest proportional volume in both species. No difference was found in the mean prey volume per stomach. Detrended correspondence analysis distribution scores indicated a greater diet breadth for P. atim than P. cuvieri, which is consistent with a higher trophic niche breadth in P. atim than P. cuvieri. According to a multi-response permutation procedure analysis, P. cuvieri and P. atim have different diet compositions. Our findings suggest that these congeneric species occupy sufficiently different dietary niches to enable them to persist in sympatry.

We describe a new species of snail-eating snake from two localities within the Atlantic Forest of the states of Bahia and Minas Gerais, Brazil. The new species differs remarkably from all congeners by its dorsal pattern consisting of sharply bordered triangles resembling the pattern of sympatric pitvipers, more precisely Bothrops jararaca and B. pirajai. Parameters of external morphology of the new species resemble those of the Dipsas incerta species group. Its scalation, body/head shape, and color pattern are most similar to D. alternans, a species known to occur 360 km farther south, across the Rio Doce river. The new species differs from D. alternans by exhibiting triangular dorsal blotches and a higher number of pileus blotches, by the distribution of ventral spots and morphology of the supratemporal and premaxillae, as well as in hemipenial morphology. We also provide comparisons of the new species with all sympatric and/or parapatric congeners. The finding of a new snake species in the Atlantic rainforest of southern Bahia and adjacent Minas Gerais is particularly surprising as this region is easily accessible and represents a well-sampled area regarding herpetological surveys in the last decades.

Population declines are noticeable when adults disappear locally or massive die-offs are reported. However, populations can slowly decline if recruitment is unsuccessful. We aimed to determine the recruitment rates and the biotic factors involved in the metamorphosing success of a threatened species, Melanophryniscus montevidensis. Using in situ enclosures in ponds of a protected area (Laguna de Rocha, Rocha, Uruguay), we assessed larval survivorship, body size, and duration of development, from eggs to the end of metamorphosis. Also, we evaluated which factors of the larval dynamics (density, body size, predation, location, and depth) better explain the overall survivorship using generalized linear models (GLMs). We recorded metamorphs in only 8 of 25 clutches, accounting for a median success per clutch of 1.2%. Median development time until Gosner stage 42 was 26 days, with a median body length of 6.1 mm. The best simplified GLM for survival success included number of larvae (recorded 10 days before sampling) and depth as significant negative predictors and body length as a positive predictor. Depth and body length had the greatest effect. The body size at metamorphosis was negatively correlated to development time, suggesting a delayed growth possibly involved in the lack of response to pond duration (causing mass mortalities) in some enclosures. In spite of the potential plasticity of the species to respond to pond desiccation, we predicted that ponds that dry in less than 20 days might not yield any offspring. The in situ data provided by this study may help understanding the processes behind the decline of M. montevidensis, thus helping to establish proper conservation actions for the populations and the ponds where they breed.

The slender and elusive Nototriton brodiei is known only from a few specimens at two separate sites in the Sierra de Merendón, in Guatemala and Honduras. We present the first record of an aggregation of three adults of N. brodiei on a single leaf in the cloud forest of Cusuco National Park, Honduras. We observed two males and one female walking together at night, using one another as support to move across vegetation. This behavior is the first record of both sexes interacting for this species, and might represent courtship strategy or similar behavior. This observation is a contribution to the sparse natural history and ecology literature for this genus. Our observation highlights the need for herpetological research on little-known and imperiled species endemic to cloud forests in Central America.

Oviposition site selection directly affects biological fitness and is related to a large number of environmental factors. A conserved trait that constrains oviposition site selection in tree frogs is the laying of clutches in vegetation overhanging water bodies. Some factors that determine oviposition site selection in tree frogs are presence of predators, water temperature, desiccation risk, laying substrate, and the chemical traits of the water body. Agalychnis moreletii and A. callidryas are widespread throughout Central America, but their populations are declining due to deforestation, presence of pathogens, species smuggling, and changes in rainfall patterns caused by global warming. We studied the oviposition site selection of the aforementioned species in four sympatric sites in southern Mexico. We characterized the vegetation, pond area and depth, temperature, and precipitation of the four sites. Each site was visited three times per week for 4 mo to record clutch development and condition, the number of eggs, substrate species, distance to the pond, and sunlight incidence. We detected a total of 404 clutches of both species in all study sites. We used generalized linear models to explore the differences among sites and determine which variables most affected clutch condition. We found significant differences in vegetation structure and pond area and depth among sites. Oviposition site selection was observed at two different scales, and reproductive success was determined by precipitation, light incidence, and substrate availability. The non-random oviposition site selection suggests that both species rely on primary forest structure for a successful reproduction. This information emphasizes the prominent role of primary forest complexity in the reproductive success of these species.

Bokermannohyla ahenea is endemic to the Serra da Bocaina, a portion of the Serra do Mar in the Atlantic Forest of Southeastern Brazil. Little information is currently available about this species. Herein, we describe the larval morphology of B. ahenea, including internal oral features, chondrocranium, and hyobranchial apparatus, along with its advertisement call and natural history notes. This is the first description of the chondrocranium and hyobranchial apparatus for a member of the genus Bokermannohyla. The larval external morphology of B. ahenea is similar to those of other species of the B. circumdata group, but it can be distinguished from those of other species of the genus by its oral apparatus. The advertisement call of B. ahenea is complex with many numbers of notes. Also, spectral and temporal parameters of the advertisement call can be used to distinguish B. ahenea from its congeners.