Predation risk is a function of seasonality rather than habitat complexity in a tropical semiarid forest.

Predator-prey dynamics are some of the most important species' interactions in the natural structuring of communities, and are among the more complex ecological processes studied by ecologists. We measured predation risk using artificial lizard replicas to test two competing hypotheses regarding predation pressure in semi-arid environments: (1) predation risk is dependent on the habitat structural complexity; and (2) predation risk is dependent on seasonality. We placed 960 lizard replicas along three sites with different physical structures and in both dry and rainy seasons for seven consecutive days in a caatinga area in northeastern Brazil at Grota do Angico Natural Monument (GANM). Birds were responsible for the majority of attacks and more frequently on artificial lizards placed in trees. Attacks focused on the most vulnerable areas of the body (head and torso), proving that were perceived by predators as true prey items. We found that predation risk is not dependent on the habitat structural complexity, but rather dependent on the caatinga seasonality, with the overall attack rate being 19% higher in the dry season. Our study suggests that potential predation risk is highly context-dependent and that seasonality consistently drives of trophic interactions strength in the caatinga, an important ecological finding that could contribute to better understanding the complex evolution of predator-prey interactions within communities of animals living in different habitats.

Chromosomal analysis of Physalaemus kroyeri and Physalaemus cicada (Anura, Leptodactylidae).

All the species of Physalaemus Fitzinger, 1826 karyotyped up until now have been classified as 2n = 22. The species of the Physalaemus cuvieri group analyzed by C-banding present a block of heterochromatin in the interstitial region of the short arm of pair 5. Physalaemus cicada Bokermann, 1966 has been considered to be a member of the Physalaemus cuvieri species group, although its interspecific phylogenetic relationships remain unknown. The PcP190 satellite DNA has been mapped on the chromosomes of most of the species of the Physalaemus cuvieri group. For two species, Physalaemus cicada and Physalaemus kroyeri (Reinhardt & Lütken, 1862), however, only the chromosome number and morphology are known. Given this, the objective of the present study was to analyze the chromosomes of Physalaemus cicada and Physalaemus kroyeri, primarily by C-banding and PcP190 mapping. The results indicate that Physalaemus kroyeri and Physalaemus cicada have similar karyotypes, which were typical of Physalaemus. In both species, the NORs are located on the long arm of pair 8, and the C-banding indicated that, among other features, Physalaemus kroyeri has the interstitial band on chromosome 5, which is however absent in Physalaemus cicada. Even so, a number of telomeric bands were observed in Physalaemus cicada. The mapping of the PcP190 satellite DNA highlighted areas of the centromeric region of the chromosomes of pair 1 in both species, although in Physalaemus kroyeri, heteromorphism was also observed in pair 3. The cytogenetic evidence does not support the inclusion of Physalaemus cicada in the Physalaemus cuvieri group. In the case of Physalaemus kroyeri, the interstitial band on pair 5 is consistent with the existence of a cytogenetic synapomorphy in the Physalaemus cuvieri species group.

Herpetofauna of protected areas in the Caatinga III: The Catimbau National Park, Pernambuco, Brazil / Herpetofauna em unidades de conservação da Caatinga III: Parque Nacional do Catimbau, Pernambuco, Brasil

Despite the increase in herpetofaunal inventories in the Caatinga biome, information for many areas is still lacking and new surveys are required. We conducted a 30-day inventory of the herpetofauna of the Catimbau National Park, Pernambuco State, Brazil. Thirty-seven pitfall trap arrays composed of 4 buckets each, along with glue traps and active searches were used to sample local herpetofaunal diversity. We recorded 21 species of frogs, 25 lizards, 11 snakes, and 1 chelonian. All sampling methods contributed significantly to achieve the amphibian and reptile diversity recovered in the inventory. Rarefaction curves and richness estimators suggest that local biodiversity is still underestimated. We attempted to show the great potential of Catimbau National Park, characterized by the richest herpetofauna surveyed in a core region of the biome, along with the presence of endemic species such as the worm snake Amphisbaena supranumeraria and the limbless lizard Scriptosaura catimbau, underscoring the importance of the area for the conservation and maintenance of the Caatinga herpetofauna biodiversity.

Apesar do crescente aumento nos inventários de herpetofauna no bioma Caatinga, ainda faltam informações para muitas áreas e novos estudos são necessários. O Parque Nacional do Catimbau, Pernambuco, Brasil, foi inventariado entre os meses de março e abril de 2013 totalizando 30 dias de amostragem, para descrever a herpetofauna local. Foram utilizados 37 pontos amostrais de armadilhas de interceptação e queda, onde cada ponto era composto por quatro baldes conectados por cercas-guia. Armadilhas de cola e procura ativa também foram métodos utilizados para amostrar a diversidade de anfíbios e répteis. Foram registradas 21 espécies de anfíbios, 25 espécies de lagartos, 11 espécies de serpentes e uma tartaruga. Todos os métodos de amostragem contribuíram para o inventário. As curvas de rarefação e os estimadores de riqueza sugerem que a diversidade local ainda está subestimada. Nós apresentamos o grande potencial do Parque Nacional do Catimbau, caracterizado pela mais rica herpetofauna inventariada na região central do bioma, e tambémpela presença de espécies endêmicas como Amphisbaena supranumeraria e Scriptosaura catimbau, evidenciando a importância da área para a manutenção e conservação da herpetofauna da Caatinga.

Nicho ecológico e aspectos da história natural de Phyllomedusa azurea (Anura: Hylidae, Phyllomedusinae) no Cerrado do Brasil Central / Ecological niche and aspects of the natural history of Phyllomedusa azurea (Anura: Hylidae, Phyllomedusinae) in the Cerrado of Central Brazil

Aspectos da ecologia e da história natural de Phyllomedusa azurea foram estudados em uma área de cerrado do Brasil Central, entre abril de 2006 e fevereiro de 2007. As observações foram realizadas entre as 18:00 e 5:00 h. Os aspectos investigados são referentes aos nichos espacial, temporal e trófico, morfometria e reprodução. A maioria dos animais vocalizou em locais com predominância do estrato herbáceo e de dossel aberto. Os principais substratos utilizados foram arbustos e árvores. Com relação às alturas de empoleiramento, os animais foram encontrados principalmente em locais entre 0,50 e 1,00 m de altura. As amplitudes de nicho espacial (substrato e altura de empoleiramento) foram respectivamente 2,91 e 3,83. A maioria dos animais foi encontrada próxima a corpos d'água lênticos, normalmente até 0,50 m. É possível que essas características estejam primariamente relacionadas com a filogenia do gênero e secundariamente às necessidades particulares da espécie e à disponibilidade local de recursos. Os arbustos e árvores utilizados pela espécie servem como sítios de vocalização e ovoposição. Os espécimes de Phyllomedusa azurea foram localizados principalmente entre às 20:00 e 21:00 h. A largura de nicho temporal estimada (horário de atividade) foi de 4,68. Padrão reprodutivo prolongado foi também observado, predominando nos meses de maior temperatura e umidade (setembro a fevereiro). A dieta constituiu-se de 11 itens, sendo que o item mais importante para as fêmeas foi Orthoptera (IVI = 63) e para os machos Araneae (IVI = 43). As amplitudes numérica e volumétrica do nicho trófico foram respectivamente 1,80 e 1,16, para fêmeas, e 4,03 e 3,92, para machos. Machos e fêmeas diferiram em tamanho (CRC) e massa, com as fêmeas sendo maiores e mais pesadas. Os tamanhos dos menores indivíduos reprodutivos de machos e fêmeas foram 34,64 e 40,33 mm, respectivamente. Diferenças no tamanho podem estar relacionadas a distintos investimentos na reprodução...

Aspects of the ecology and natural history of Phyllomedusa azurea were investigated in an area of Central Brazilian Cerrado between April, 2006, and February, 2007. Observations were conducted between 6:00 PM and 5:00 AM. The study focused on spatial, temporal, and trophic niches, morphometry and reproduction. Most animals were recorded vocalizing in places dominated by herbaceous vegetation and an open canopy. The main substrates used were bushes and trees, and animals were seen perched most often between 0.5 and 1.0 m of height. Spatial niche breadth was 2.91 and 3.83 for substrate and perch height, respectively. Most animal were sighted close to lentic water bodies, usually up to 0.50 m. It is possible that these characteristics are related primarily to the phylogeny of the genus and secondarily to the specific needs of the species and the local availability of resources. The bushes and trees were used by the species mainly as sites of vocalization and oviposition. Specimens of Phyllomedusa azurea was sighted most frequently between 8:00 PM and 9:00 PM. Estimated temporal niche breadth (activity period) was 4.68. Prolonged reproductive pattern was also observed predominantly in the months with higher temperature and higher humidity (September to February). The diet consisted of eleven items. The most important prey taxon for the females was Orthoptera (IVI = 63), whereas for the males, it was Araneae (IVI = 33). The breadths numeric and volumetric of the trophic niche, was respectively 1.80 and 1.16, for females, and 4.03 and 3.92, for males. Males and females differed in size (SVL) and mass, with the females being larger and heavier. The sizes of smaller reproductive individuals males and females were 34.64 and 40.33 mm, respectively. Differences in size may be related to different investments in reproduction by the two sexes.

História natural de Leptodactylus mystacinus e Leptodactylus fuscus (Anura: Leptodactylidae) no Cerrado do Brasil Central / Natural history of Leptodactylus mystacinus and Leptodactylus fuscus (Anura: Leptodactylidae) in the Cerrado of Central Brazil

Aspectos da ecologia de Leptodactylus mystacinus e Leptodactylus fuscus foram investigados em uma área de Cerrado do Brasil Central. O estudo incluiu o uso do microhábitat, padrões de atividade, dieta e morfometria. As observações foram conduzidas entre abril de 2006 a fevereiro de 2007. As espécies são sexualmente dimórficas - fêmeas maiores que os machos - e o tamanho do corpo em L. mystacinus é maior do que o de L. fuscus. Ambas as espécies preferiram a superfície do solo (microhábitat) de hábitats brejosos com vegetação herbácea próximos a corpos lênticos de água. Leptodactylus mystacinus foi mais observado em Outubro e Novembro (20:00-20:59 e 23:00-23:59 horas) e L. fuscus em Novembro e Outubro das 19:00 às 20:59 horas. A dieta destas populações foi baseada em Arthropoda, primariamente Coleoptera, a qual foi a mais importante ordem (IVI). Diferenças nas proporções volumétricas das categorias de presas utilizadas, e nos períodos em que são mais observadas, provavelmente sejam os fatores que mais contribuem para a coexistência das duas espécies na área. Diferenças intersexuais na dieta foram observadas para estas espécies. Estas diferenças estão provavelmente associadas à alocação diferencial de recursos para a produção de gametas ou diferenças ocasionais no uso do espaço pelos dois sexos.

Aspects of the ecology of Leptodactylus mystacinus and Leptodactylus fuscus were investigated in an area of the Cerrado of Central Brazil. The study included use of microhabitat, activity patterns, diet and, morphometry. Observations were conducted between April, 2006, and February, 2007. The species are sexually dimorphic - females larger than males - and body size in L. mystacinus is larger than that of L. fuscus. Both species preferred the ground surface (microhabitat) of wetland habitats with herbaceous vegetation close to lentic water bodies. Leptodactylus mystacinus was observed most often in October and November (8:00-8:59PM and 11:00-11:59 PM), and L. fuscus in November and October between 7:00 PM and 8:59 PM. The diet of both populations was based on Arthropoda, primarily Coleoptera, which was the most important order (IVI). Differences in the volumetric proportions of the categories of then preys used, and in the periods when they were most observed, are probably the factors that contribute the most to the coexistence of both species in the area. Intersexual differences in the diet were observed in both species. These differences were probably associated with the differential allocation of resources to the production of gametes or occasional differences in the use of space by the two sexes.

História natural de Tropidurus oreadicus em uma área de cerrado rupestre do Brasil Central / Natural history of Tropidurus oreadicus in a rocky cerrado area of Central Brazil

Aspectos ecológicos e da biologia reprodutiva de Tropidurus oreadicus foram investigados em uma área de cerrado rupestre do Brasil Central. Foram estudados a morfometria, o uso do microhábitat, o padrão de atividade, a dieta e características da biologia reprodutiva de T. oreadicus em Cocalzinho - GO, de abril a setembro/2003. São animais sexualmente dimórficos, com os machos adultos maiores que as fêmeas. O microhábitat preferencial utilizado pela espécie foi a superfície das rochas (hábito saxícola). A espécie mostrou padrão de atividade unimodal. Foram frequentemente observados parados e expostos ao sol entre 9:00 e 10:59 horas. A alimentação desta população de T. oreadicus é baseada em formigas, larvas de inseto e besouros. Além disso, apresentaram mudanças ontogenéticas e diferenças intersexuais na dieta. Provavelmente essas diferenças estejam associadas à alocação diferenciada dos recursos para o crescimento ou produção dos gametas. A reprodução é provavelmente sazonal ocorrendo principalmente nos meses de maior pluviosidade.

Ecological aspects and of the reproductive biology of Tropidurus oreadicus was investigated in a rocky cerrado area in Central Brazil. It was studied the morphometry, the microhabitat use, the activity pattern, the diet and the characteristics of the reproductive biology of T. oreadicus in Cocalzinho-GO, from April to September/2003. They are sexually dimorphic animals, with adult males larger than females. The preferential microhabitat used by the species was the surface of the rocks (saxicolous habit). The species shows a unimodal activity pattern. It was frequently observed resting and exposed to the sun between 9:00 and 10:59 hours. This T. oreadicus population feed upon ants, larvae of insects and beetles. Besides it presented ontogenetics shift and intersexual differences in the diet. Probably these differences were associated with the differentiated allocation of the resources for the growth or production of gamete. The reproduction is probably seasonal occurring mainly during the months of higher rainfall.