Search Results

Restricted Access

Cynthia Prado, Masao Uetanabaro and Célio Haddad

Abstract

Annual patterns of breeding activity, reproductive modes, and habitat use are described for a frog community in a seasonal environment, in the southern Pantanal, Mato Grosso do Sul, Brazil. Data were collected monthly between January 1995 and December 1998. A total of 24 species from four families; Bufonidae (3 species), Hylidae (10 species), Leptodactylidae (9 species), and Microhylidae (2 species) were registered. Three reproductive activity patterns are recognized among these species: continuous, explosive, and prolonged; 50% of the species were explosive breeders. Seasonal pattern of reproduction was verified for three analyzed years (1995-1997); most species reproduced during the rainy season (Nov-Jan). The reproduction was aseasonal in 1998; unexpected rains in the dry season lead to an unusual breeding activity. Five reproductive modes were noted — 62.5% of the species have the generalized aquatic mode, and 33.3% deposit eggs embedded in foam nests. Many species used the same sites for reproduction, although temporal partitioning and calling site segregation was observed. The occurrence of many species that exhibit explosive breeding early in the rainy season is common in seasonal and open environments with variable and unpredictable rainfall, as is the case in the Pantanal.

Restricted Access

Renato C. Nali and Cynthia P.A. Prado

The richest anuran fauna is found in the Neotropics, but the natural history of most species is unknown. Bokermannohyla ibitiguara is a stream-dweller treefrog endemic to the Brazilian Cerrado and classified as “Data Deficient” by the IUCN. Herein we describe the species’ reproductive biology. Fieldwork was conducted from August 2010 to July 2011. Reproductive activity occurred from October to June and was positively correlated with air temperature, humidity, and monthly rainfall. Individuals were observed only in gallery forests at the margins of streams and males used various kinds of substrates as calling sites. Males did not aggregate in specific parts of the streams and spatial distance between males was higher in the dry season. Males and females did not differ in length, but females without mature oocytes were lighter than males. The reproductive investment (gonad mass/body mass) of males was 0.29% and that of females was 20.26%. Female ovaries contained a mean of 202 ± 75 mature oocytes with a mean diameter of 1.96 ± 0.16 mm. We describe, for the first time for the genus, a complex courtship behaviour and also male-male fight and satellite behaviour. The Cerrado is probably the most threatened savanna in the world, having been intensively modified over the last decades. Endemic species associated to gallery forests, such as B. ibitiguara, are highly vulnerable to habitat alterations. Thus, our study provides important data on the species’ biology, which might be useful for conservation practices, but also to investigate taxonomic and phylogenetic relationships in this genus.

Restricted Access

Renato C. Nali, Kelly R. Zamudio and Cynthia P.A. Prado

We characterized 22 polymorphic microsatellite markers for the Brazilian treefrog Bokermannohyla ibitiguara and tested their cross-amplification in B. alvarengai, B. circumdata and B. hylax. Our focal species occurs in protected and disturbed Brazilian Cerrado landscapes, a highly threatened savanna in central Brazil. Fourteen markers successfully cross-amplified for at least one congener. These microsatellites will be useful for studies of mating systems, relatedness and landscape genetics of Cerrado populations under various deforestation levels. Moreover, variable markers for B. circumdata and B. hylax will also be useful for landscape genetic studies of taxa typical of the threatened Atlantic Forest domain.

Restricted Access

Nadya C. Pupin, Célio F.B. Haddad and Cynthia P.A. Prado

In some environments prevailing conditions are unpredictable, thus anuran species use bet-hedging strategies and produce eggs of varied sizes. We investigated whether four species of Physalaemus (two from open, two from forest habitats) exhibit bet-hedging strategies, and if intra-clutch variation in egg size is greater for species that breed in the more unpredictable ponds of open habitats. All species studied adopted the bet-hedging strategy, with intra-clutch variation in egg size regardless of the environment; however, we found greater intra-clutch variation in the two species from open areas. The lower variation in egg-size found within forest habitats may be explained by the more stable environments that forest ponds provide for anuran eggs/embryos. Future studies in a phylogenetic context are needed to confirm the patterns detected here.

Restricted Access

Rubens A.F. Turin, Renato C. Nali and Cynthia P.A. Prado

Vocalisation is one of the most conspicuous behavioural traits in different animals, but its emission can be variable within species, depending on environmental, morphological, and/or social factors. Understanding how acoustic parameters vary can provide information about sexual selection mechanisms that might have shaped the species’ evolutionary history. We quantified and compared the variation of five call parameters within and among the males of Bokermannohyla ibitiguara, a Neotropical treefrog with complex reproduction and advertisement calls. The parameters were classified as static (dominant frequency), intermediate (note durations) or dynamic (pulse rate of the long note and call duration). Despite these differences, all of them varied more among individuals than within individuals, and most were associated with individual discrimination, showing potential acoustic recognition by males and females. A multiple regression analysis showed that all temporal parameters were affected by abiotic factors, except pulse rate of the long note; body size affected dominant frequency, duration of the long notes and call duration. This high variability in parameters, and the strong support for individual discrimination, indicate the existence of sexual selection mechanisms operating on calls; however, the individual recognition system is very complex and not limited to a single characteristic of the call. This is supported by the reproductive behavior of this species, including choosy females, elaborate courtships, and male-male vocal contests and physical combats. Fine-scale playback experiments with males and females will help us further understand sexual selection mechanisms in this and other acoustically oriented animals.

Restricted Access

Gabriel P. Faggioni, Gabriel P. Faggioni, Kelly R. Zamudio, Gabriel P. Faggioni, Kelly R. Zamudio, Franco L. Souza, Gabriel P. Faggioni, Kelly R. Zamudio, Franco L. Souza and Cynthia P.A. Prado

Leptodactylus bufonius (Vizcacheras’ white-lipped frog) and L. chaquensis (Cei’s white-lipped frog) are pond-breeding frogs that inhabit the Chaco and surrounding savanna-like formations in South America. Throughout the Chacoan plain, the combined impacts of livestock and forestry practices have led to a highly fragmented landscape and an impoverished ecological system, threatening local species. We cloned and characterized new microsatellite markers for both species. These markers will be useful for behavioral and conservation genetic studies of populations throughout this threatened habitat.