Habitat structure and their influence in lizard's presence

Many species are declining due to environmental and physical changes in their habitats. Such disturbs alter the availability of micro-habitats and influences the presence of lizards, being even worse for threatened and endemic species. Glaucomastix littoralis is a teiid species restricted to four restingas areas of Brazil. The understanding about the use and preferences of micro-habitats by the species and the consequents effects of substrate loss is important to prevent local extinctions. This study took place in restingas of Maricá, Jurubatiba and Grussaí, in Rio de Janeiro State. We sampled the vegetation of all areas, to access differences between the physical structures, and recorded the individuals sighted and the micro-habitat they were in, to investigate the relation of individuals and habitat structure. We calculated the frequency utilization of each micro-habitat and made a presence estimation of individuals (occupancy and detection probability) to assess which structural parameters of vegetation guide the settlement of the studied populations. Our data showed structural vegetation particularities among the areas and a trend concerning the use of micro-habitat by Glaucomastix littoralis, with a general preference for leaf litter inside bushes, guriri and bare sand and a low utilization of cactus and herbaceous. We also found positives (bare sand and cactus) and negatives (bushes) influences of micro-habitats in relation to the occupation of the areas by the individuals. Since vegetation is fundamental to lizards, due to their use as a refuge, site for thermoregulation and feeding, the understanding about the effects habitat degradation/fragmentation can cause is essential to create appropriate management plans and develop public policies to conserve the species.(AU)

Habitat structure and their influence in lizard's presence

Many species are declining due to environmental and physical changes in their habitats. Such disturbs alter the availability of micro-habitats and influences the presence of lizards, being even worse for threatened and endemic species. Glaucomastix littoralis is a teiid species restricted to four restingas areas of Brazil. The understanding about the use and preferences of micro-habitats by the species and the consequents effects of substrate loss is important to prevent local extinctions. This study took place in restingas of Maricá, Jurubatiba and Grussaí, in Rio de Janeiro State. We sampled the vegetation of all areas, to access differences between the physical structures, and recorded the individuals sighted and the micro-habitat they were in, to investigate the relation of individuals and habitat structure. We calculated the frequency utilization of each micro-habitat and made a presence estimation of individuals (occupancy and detection probability) to assess which structural parameters of vegetation guide the settlement of the studied populations. Our data showed structural vegetation particularities among the areas and a trend concerning the use of micro-habitat by Glaucomastix littoralis, with a general preference for leaf litter inside bushes, guriri and bare sand and a low utilization of cactus and herbaceous. We also found positives (bare sand and cactus) and negatives (bushes) influences of micro-habitats in relation to the occupation of the areas by the individuals. Since vegetation is fundamental to lizards, due to their use as a refuge, site for thermoregulation and feeding, the understanding about the effects habitat degradation/fragmentation can cause is essential to create appropriate management plans and develop public policies to conserve the species.

Species composition and density estimates of the anurofauna of a site within the northernmost large Atlantic Forest remnant (Parque Estadual do Desengano) in the state of Rio de Janeiro, Brazil / Composição de espécies e estimativa de densidade da anurofauna em uma área dentro do mais setentrional dos grandes remanescentes de Mata Atlântica (Parque Estadual do Desengano) do Estado do Rio de Janeiro, Brasil

We present data on species composition, relative abundance and estimated densities for leaf-litter anuran amphibians from an Atlantic Forest area within the Parque Estadual do Desengano, in the state of Rio de Janeiro, Brazil, based on results of a short-term survey carried out during the winter at altitudes of 1000-1500 m. Three sampling methods were used: plot sampling, visual encounter surveys (VES; performed during the day, at the twilight, and at night), and pitfall traps. We recorded 13 species, with the direct-developer Ischnocnema parva (Girard, 1853) being the most abundant. Most frogs (ca. 90% of all individuals) sampled by VES were captured during the crepuscular and nocturnal periods. The estimated density of the local leaf-litter frog assemblage based on plot sampling was 13.2 ind.100 m-2, which is one of the highest values currently reported for Atlantic Rainforest areas. This is the first study analyzing the anuran fauna of the Parque Estadual do Desengano and adds to the knowledge of the fauna of the northern region of the state of Rio de Janeiro, which is still poorly studied.

Apresentamos dados sobre a composição de espécies, abundância relativa e densidade estimada para anfíbios anuros de serrapilheira de uma área de Mata Atlântica no Parque Estadual do Desengano, no Estado do Rio de Janeiro, Brasil, com base em resultados de um estudo de curto prazo realizado durante o inverno a altitudes de 1000-1500 m. Três métodos de amostragem foram utilizados: amostragem em parcelas, encontros visuais (realizados durante o dia, no crepúsculo e à noite) e armadilhas de queda. Foram registradas 13 espécies, com Ischnocnema parva (Girard, 1853), uma forma com desenvolvimento direto, sendo a mais abundante. A maioria dos anuros (ca. 90% de todos os indivíduos) amostrados pelo método de encontros visuais foi coletada durante os períodos crepuscular e noturno. A densidade estimada para anuros de serrapilheira foi de 13,2 ind.100 m-2, que é um dos valores mais altos atualmente registrados para áreas de Mata Atlântica. Este é o primeiro estudo que analisa a fauna de anuros do Parque Estadual do Desengano e contribui para o conhecimento da fauna da região norte do estado do Rio de Janeiro, que ainda é pouco estudada.

Termorregulação no lagarto partenogenético Cnemidophorus nativo [Teiidae] em uma Área de Restinga do Nordeste do Brasil / Thermoregulation in the parthenogenetic lizard Cnemidophorus nativo [Teiidae] in a restinga habitat of northeastern Brasil

Estudamos o comportamento de termorregulação e uso do habitat do lagarto teídeo partenogenético Cnemidophorus nativo e o efeito de variáveis ambientais na regulação de sua temperatura corpórea, na Restinga de Guaratiba, Prado, Bahia. Os lagartos foram coletados mensalmente, sendo medidas: a temperatura da cloaca [Tb], a temperatura do ar [Ta] e temperatura do substrato [Ts] com um termômetro cloacal Schultheis [precisão de 0,2°C], sendo registrado o microhabitat de cada lagarto. Cnemidophorus nativo em Guaratiba possui Tb de 39,0+2,0°C [31-42°C]. A relação entre a Tb e Ta foi significativa [F= 24,211,86; R2= 0,220; p<0,001], assim como a relação entre Tb e Ts [F = 27,401,51; R2 = 0,35; p<0,001]. A Tb não estava relacionada com o comprimento rostro-anal [F=3,131,95; R2 =0,032; p=0,08]. A Tb diferiu significativamente entre as estações [p=0,008] indicando que variações nas temperaturas ambientais afetam a Tb da espécie. Cnemidophorus nativo é uma espécie diurna com Tb relativamente elevada, necessária para manter a sua elevada taxa de movimentação. Os dados indicaram que Ta e Ts interagem para influenciar a Tb e ambas explicam apenas uma pequena parte da Tb o que é esperado para forrageadores ativos que se deslocam continuamente [AU]