Rodrigo B. Ferreira

Diet, Fecundity, and Use of Bromeliads by Phyllodytes luteolus (Anura: Hylidae) in Southeastern Brazil

Abstract This study explores the feeding ecology, habitat use, and fecundity of Phyllodytes luteolus inside bromeliads in the restinga of Regência (sandy coastal plain), Espírito Santo state, southeastern Brazil. Because bromeliads are harvested for commercial use, and frogs may be collected accidently, the ecology of this frog is of particular interest. We collected 363 individuals of P. luteolus (103 tadpoles, 74 juveniles, 64 males, and 122 females) from three species of bromeliads in a 4-km2 area bimonthly from February to December of 1998. Ants and termites were the dominant food items in terms of number and mass over time. The percentage of prey items and the size of prey eaten by juveniles differed significantly from those of adults. Dominant prey items were relatively similar across the sampled bromeliad species and locations. Phyllodytes luteolus preferred Vriesea procera, the most-complex bromeliad in our study site. Half of the individuals were found in bromeliads located in transitional zones. Female P. luteolus were slightly larger than the males, which may have determined the strong sex ratio bias toward females. We found females with developed oocytes (range 11–15) in every sampled month, indicating a protracted spawning period. This frog can be considered an active forager and specialist, feeding preferentially on colonial insects. Phyllodytes luteolus uses several species of harvested bromeliads and possesses several attributes that could facilitate its success as an invasive species.

Establishment of introduced reptiles increases with the presence and richness of native congeners

Darwin proposed two contradictory hypotheses to explain the influence of congeners on the outcomes of invasion: the naturalization hypothesis, which predicts a negative relationship between the presence of congeners and invasion success, and the pre-adaptation hypothesis, which predicts a positive relationship between the presence of congeners and invasion success. Studies testing these hypotheses have shown mixed support. We tested these hypotheses using the establishment success of non-native reptiles and congener presence/absence and richness across the globe. Our results demonstrated support for the pre-adaptation hypothesis. We found that globally, both on islands and continents, establishment success was higher in the presence than in the absence of congeners and that establishment success increased with increasing congener richness. At the life form level, establishment success was higher for lizards, marginally higher for snakes, and not different for turtles in the presence of congeners; data were insufficient to test the hypotheses for crocodiles. There was no relationship between establishment success and congener richness for any life form. We suggest that we found support for the pre-adaptation hypothesis because, at the scale of our analysis, native congeners represent environmental conditions appropriate for the species rather than competition for niche space. Our results imply that areas to target for early detection of non-native reptiles are those that host closely related species.

Continental,insular and coastal marine reptiles from the municipality of Vitória, state of Espirito Santo,southeastern Brazil

We present a list of the reptiles of the municipality of Vitoria, Espirito Santo, Brazil, compiled through primary data (specimens gathered by the authors) and secondary data (specimens housed at museums and records available in literature). We record 51 reptile species distributed by the orders Crocodylia (one species), Testudines (nine species), and Squamata (forty-one species), subdivided in amphisbaenians (three species), lizards (eleven species), and snakes (twenty-seven species). We recorded six species that are listed as threatened in the Brazilian List of Endangered Species, as the terrestrial lizard Cnemidophorus nativo and the marine turtles Lepidochelys olivacea and Dermochelys coriacea .

A new diminutive frog species of Adelophryne (Amphibia: Anura: Eleutherodactylidae) from the Atlantic Forest, southeastern Brazil

The genus Adelophryne is composed of diminutive frogs occurring in northern Amazonia and the Atlantic Forest. Herein we describe a new species of Adelophryne found in the leaf litter of primary and secondary forests in the mountainous region of Espírito Santo state, southeastern Brazil. The new species is characterized by its small body size, two phalanges in the finger IV, and a glandular ridge line that runs from the posterior part of eye to the insertion of the forelimb. This species is sensitive to edge effect and conversion of native forest into coffee and Eucalyptus plantations and may be listed as Endangered (EN) under B1ab(iii) criteria of the IUCN Red List.

Distribuição espacial e sazonal de anfíbios em quatro poças na região serrana do Espírito Santo, sudeste do Brasil: influência de corredores florestais

This study evaluated the composition of anuran assemblages, and also the spatial and temporal distribution of those species in four permanent ponds. Two of these ponds are connected to Atlantic rainforest fragments by forest corridor and the other two are surrounded by Eucalyptus plantation and human settlement. Twenty-two species from five families were recorded from December 2003 to November 2004. Most species and individuals collected belong to Hylidae, which presented pronounced spatial overlap. Vegetation under 0.60 m was the most used calling site. Although not statistically supported, species richness and abundance were higher in rainy than dry months. Ponds with corridors had higher species richness and fourteen species were exclusively found on these ponds. The community structure of anurans in permanent ponds at this fragmented landscape is apparently dictated by the presence or absence of forest corridors connecting ponds to forest fragments.

The First Bromeligenous Species of Dendropsophus (Anura: Hylidae) from Brazil's Atlantic Forest

We describe a new treefrog species of Dendropsophus collected on rocky outcrops in the Brazilian Atlantic Forest. Ecologically, the new species can be distinguished from all known congeners by having a larval phase associated with rainwater accumulated in bromeliad phytotelms instead of temporary or lentic water bodies. Phylogenetic analysis based on molecular data confirms that the new species is a member of Dendropsophus; our analysis does not assign it to any recognized species group in the genus. Morphologically, based on comparison with the 96 known congeners, the new species is diagnosed by its small size, framed dorsal color pattern, and short webbing between toes IV-V. The advertisement call is composed of a moderate-pitched two-note call (~5 kHz). The territorial call contains more notes and pulses than the advertisement call. Field observations suggest that this new bromeligenous species uses a variety of bromeliad species to breed in, and may be both territorial and exhibit male parental care.

Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil’s Atlantic Forest

Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil’s Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest edge, and iv) 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types). By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders) was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm) and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in response to edge effect and matrix types, and can guide more effective management and conservation actions.

Global assessment of establishment success for amphibian and reptile invaders

Abstract Context. According to the tens rule, 10% of introduced species establish themselves. Aims. We tested this component of the tens rule for amphibians and reptiles globally, in Europe and North America, where data are presumably of good quality, and on islands versus continents. We also tested whether there was a taxonomic difference in establishment success between amphibians and reptiles. Methods. We examined data comprising 206 successful and 165 failed introduction records for 161 species of amphibians to 55 locations, and 560 successful and 641 failed introduction records for 469 species of reptiles to 116 locations around the world. Key results. Globally, establishment success was not different between amphibians (67%) and reptiles (62%). Both means were well above the 10% value predicted by the tens rule. In Europe and North America, establishment success was lower, although still higher than 10%. For reptiles, establishment success was higher on islands than on continents. Our results question the tens rule and do not show taxonomic differences in establishment success. Implications. Similar to studies on other taxa (birds and mammals), we found that establishment success was generally above 40%. This suggests that we should focus management on reducing the number of herptile species introduced because both reptiles and amphibians have a high likelihood of establishing. As data collection on invasions continue, testing establishment success in light of other factors, including propagule pressure, climate matching and taxonomic classifications, may provide additional insight into which species are most likely to establish in particular areas.

Bromeliad Selection by Phyllodytes luteolus (Anura, Hylidae): The Influence of Plant Structure and Water Quality Factors

Abstract Bromeliads are used by many frog species because of their capacity to accumulate rainwater. The bromeligenous frog, Phyllodytes luteolus (Yellow Heart-Tongued Frog), uses bromeliads for its entire life cycle including shelter, foraging, and reproduction. We evaluated the effect of plant morphometrics and the properties of water accumulated in bromeliads on the selection of these plants by P. luteolus. We sampled 103 bromeliads of which 41 were unoccupied and 62 were occupied by P. luteolus. Results suggest that bromeliad occupation by P. luteolus is nonrandom. We found that occupied plants were shorter in height, had a greater number of leaves, and had lower water conductivity than did unoccupied plants. Males were more likely to occupy plants with more leaves than were females. Plant selection may be related to the reproductive success of P. luteolus because frogs using plants with more leaves and lower conductivity may experience reductions in competition for space, predator encounters, and desiccation. Considering that illegal bromeliad harvesting threatens many bromeligenous frogs, improved understanding of bromeliad selection may determine which bromeliad species should be targeted for conservation to ensure the population viability of frogs. Resumo Bromélias são usadas por muitas espécies de anuros, devido à sua capacidade de acumular água da chuva. O anuro bromelígena Phyllodytes luteolus, usa bromélias para todo o seu ciclo de vida, incluindo abrigo, forrageamento e reprodução. Avaliamos o efeito da morfometria e as propriedades da água acumulada em bromélias na seleção dessas plantas por P. luteolus. Foram amostradas 103 bromélias, das quais 41 estavam desocupadas e 62 foram ocupadas por P. luteolus. Os resultados sugerem que a ocupação de bromélia por P. luteolus não é aleatória. Descobrimos que as plantas ocupadas eram menores, tinham um maior número de folhas, e tiveram menor condutividade da água que as plantas desocupadas. Os machos tendem a ocupar plantas com mais folhas do que as fêmeas. A seleção de bromélias pode estar relacionada com o sucesso reprodutivo de P. luteolus; por exemplo, os anuros que utilizam plantas com mais folhas e menor condutividade podem experimentar uma redução da concorrência por espaço, encontro predador, dessecação, porque mais axilas com água estarão disponíveis, resultando em um maior sucesso reprodutivo. Considerando-se que o extrativismo ilegal de bromélias ameaça muitos anuros bromelígenas, a melhor compreensão da seleção bromélia pode determinar as espécies de bromélias que devem ser priorizadas para a conservação a fim de assegurar a viabilidade da população de anuros.

The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae): incipient gigantism?

The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824), is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length) of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espirito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight) and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.