Abstract Data on the structure of lizard communities in the different biomes and ecosystems of Brazil are still limited. In this study, we related the species richness, abundance and the spatial occurrence of lizards to the structure of the vegetation found on the coast of the state of Espírito Santo, southeastern Brazil, to determine whether habitat influences the structure of lizard communities. We conducted fieldwork in 2012, 2013 and 2014, collecting data in standardized samples. We analyze whether variables of vegetation structure influenced species richness and abundance, using Generalized Linear Models (GLMs). We recorded 12 lizard species from eight families. In general, species richness and abundance were similar among sites. Locally, we recorded the highest species richness in shrubby vegetation, open Clusia vegetation, and the restinga forest zone. Bromeliads explained the occurrence of teiids, although there was no systematic relationship between species richness and vegetation structure. Our results provide important insights into the characteristics of the lizard communities found on sandy coastal plains and contribute to the conservation of these species in these ecosystems.

ABSTRACT We investigated the daily activity and thermoregulatory body orientation of Mabuya macrorhyncha (Hoge, 1947), a lizard species that occurs in the Brazilian Atlantic Forest. We conducted this investigation in a sandy coastal dune remnant (“restinga” ecosystem) in Grussaí, state of Rio de Janeiro, Brazil, during the summer. The daily activity cycle of the lizards started around 6:00 am and ended before 7:00 pm. This is longer than observed in other populations of M. macrorhyncha (approximately 7:00 am to 5:00 pm). The activity cycle of the lizards was bimodal, with the first peak between 6:00 and 11:00 am and the second from 2:00 to 7:00 pm. This contrasts with observations on other populations of this species, which revealed an unimodal pattern. The mean body temperature of M. macrorhyncha in Grussaí was 34.2 ± 1.5 °C, which was comparatively higher than observed in other populations of the species. The differences in the daily activity and of body temperature of these lizards between our study and previous studies on this species may reflect environmental thermal conditions. The mean air and mean substrate temperatures when individuals were active were 27.8 and 30.5 °C respectively. Lizard orientation was significantly correlated with the direction of the solar incidence, suggesting that solar radiation, and particularly behavioral adjustments that maximize exposure to the sun, are important for the thermoregulation of M. macrorhyncha. Circular structures at the site, such as bromeliads, offer microhabitats with different orientations to the sunlight, favoring lizard thermoregulatory behaviors.

RESUMO As comunidades são estruturadas por uma interação de fatores históricos e ecológicos que influenciam o uso de diferentes recursos no tempo e no espaço. Coletamos dados sobre tempo de atividade, o uso de micro-habitat e dieta de uma assembleia de lagartos de um habitat de restinga na costa do Sudeste do Brasil (Restinga de Jurubatiba). Os dados foram analisados em relação à sobreposição de nicho entre as espécies ao longo de três eixos (temporais, espaciais e tróficos), utilizando modelos nulos. Encontramos uma sobreposição significativa no nicho trófico, enquanto que a sobreposição para os outros eixos não diferiu do esperado. Com base neste resultado, discutimos os fatores que atuam sobre a estruturação da comunidade local de lagartos.

ABSTRACT Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

Serpentes viperídeas são amplamente distribuídas pela América do Sul, com maior radiação ocorrendo na subfamília Crotalinae. Apesar da aparente abundância dessas serpentes ao longo da sua distribuição geográfica, alguns aspectos ecológicos permanecem desconhecidos, principalmente em áreas subtropicais. No presente estudo, avaliamos a atividade (diária e sazonal) e o uso do ambiente por Bothrops diporus, B. jararaca e B. jararacussu, em uma área de Mata Atlântica, no sul do Brasil. Observamos maior incidência de viperídeos durante os meses com temperaturas mais altas, enquanto nenhuma serpente foi encontrada durante os meses de menores temperaturas. Os dados sugerem a temperatura mínima como a variável ambiental com maior influência na atividade sazonal dessas espécies. Considerando a atividade diária, observamos uma tendência das serpentes evitarem os horários com temperaturas mais altas. Bothrops jararacussu tendeu a evitar áreas mais abertas, sendo registrada apenas dentro e na borda da mata. Comparamos nossos resultados com estudos prévios realizados em áreas tropicais, e sugerimos a atividade sazonal observada como uma resposta evolutiva, apesar de influenciada por diferentes variáveis ambientais, de acordo com a região de ocorrência.

Viperid snakes are widely distributed in the South America and the greater distribution range of the family is found at the Crotalinae subfamily. Despite the abundance of this snakes along their geographic distribution, some ecological aspects remain unknown, principally at subtropical areas. In the present study, we evaluated the activity (daily and seasonal) and the use of the habitat by Bothrops diporus, B. jararaca andB. jararacussu, in an Atlantic Forest area at southern Brazil. We observed higher incidence of viperid snakes during the months with higher temperatures, while no snakes were found during the months with lower temperatures. The data suggest the minimum temperature as environmental variable with the greatest influence on the seasonal activity of this species. Considering the daily activity, we observed a tendency of snakes to avoid the warmest hours. Bothrops jararacussu tend to avoid open areas, being registered only inside and at the edges of the forest. We compared our results with previous studies realized at tropical areas and we suggest the observed seasonal activity as an evolutive response, despite the influence of the different environmental variables, according to the occurence region.

O crescimento da ocupação humana sobre ambientes naturais é uma das maiores ameaças à biodiversidade. Para amenizar os efeitos negativos antropogênicos, é necessário entender as características das populações naturais, e a história natural das espécies. Um estudo foi conduzido com uma assembeia de lagartos de uma área perturbada do Pampa, de fevereiro de 2002 a janeiro de 2004. A assembleia apresentou padrão sazonal unimodal, com recrutamento ocorrendo durante os meses mais quentes. As capturas foram sazonais durante dois dos três anos monitorados, e concentradas nos meses mais quentes. A temperatura mínima explica o número de capturas para a assembleia como um todo. Entretanto, quando as espécies foram analisadas individualmente, a variável explica apenas a ocorrência sazonal de Teius oculatus. A abundância das espécies foi significativamente distinta no terceiro ano de estudo para Cercosaura schreibersii e Ophiodes striatus. Essa última espécie não teve mais registros na área de maio de 2003 até o final do estudo. Assim, O. striatus pode ser mais sensível às udanças abientais, considerando os eventos de udança na vegetação ocorridas durante o estudo. Com as frequentes e crescentes perturbações ambientais que o bioma vem sofrendo, são necessárias ações de conservação, e dar suporte para o aumento do conhecimento dos lagartos pampeanos.

The increasing human occupation of natural environments is one of the greatest threats to biodiversity. To mitigate the negative anthropogenic effects, it is necessary to understand the characteristics of natural populations and the natural history of species. A study was conducted with an assemblage of lizards from a disturbed area of the Pampa biome, from February 2001 to January 2004. The assemblage showed a unimodal seasonal pattern, with the recruitment period occurring during the warmer months. The captures were seasonal for two of the three monitored years, and concentrated within warmer months. The minimum temperature explained the number of catches for the assemblage as a whole. However, when the species were analyzed individually, the temperature only explained the seasonal occurrence of Teius oculatus. The abundance of species was significantly different in the third year of study for Cercosaura schreibersii and Ophiodes striatus. This latter species was no longer registered in the study area from May 2003 until the end of the study. Therefore, O. striatus may be more sensitive to environmental changes, considering the events of change in vegetation during the study. With frequent and increasing environmental disturbances, it is necessary to take conservation measures and encourage the increase of knowledge on Pampean lizards.

O registro fossilífero do Quaternário de Águas de Araxá (QAA) é representado principalmente pelo acúmulo de restos dentários e de esqueleto de diversos tamanhos, atribuídos a uma população pretérita do mastodonte Stegomastodon waringi. Foram analisados 97 molares de acordo com os estágios de desgaste propostos por Simpson e Paula-Couto 1957, e desenvolveu-se um índice morfométrico de desgaste. A estrutura populacional (proporção entre indivíduos imaturos, subadultos, adultos, adultos maduros e adultos senis) foi identificada e comparada com populações de elefantes atuais. Foi possível estabelecer que esta população era amplamente composta por adultos: 14,89% eram indivíduos imaturos; 23,04% eram subadultos; 27,65% eram adultos; 17,21% eram adultos maduros e outros 17,21% eram adultos senis. Baseados na estrutura populacional observada, não se descartou a possibilidade desta população estar estável ou em recuperação e/ou de ter passado por um período de predação dos indivíduos mais jovens. O número de indivíduos encontrados nesta população sugere que esta ocupava um ambiente aberto, de acordo com comparações com populações de elefantes atuais. Considerou-se a assembléia de mastodontes do Quaternário de Águas de Araxá como uma agregação de unidades familiares, o que sugere um momento de baixa umidade ambiental. Baseados em literatura e nos resultados encontrados, a sua extinção parece ser regional e possivelmente relacionada a um evento catastrófico.

The Quaternary fossil record of Águas de Araxá (Q AA) is represented mainly by an accumulation of skeletal elements of several sizes, which are assigned to a population of Stegomastodon waringi. We analyzed 97 molars according to the ear stages of Sipson and Paula-Couto (1957), and developed a orphoetric ear index. The population structure (proportion of immature, subadult, adult, mature adult and senile adult individuals) was identified, and these five age classes were compared to those of extant elephant populations and defined with social implications. The analysis made possible to establish that the population is largely composed of adults: 14.89% are immature individuals, 23.04% subadults, 27.65% adults, 17.21% mature adults and another 17.21% senile adults. Based on population structure, we do not discard the possibility that the fossil population was stable or in recovery, and/or was experiencing a high-predation period on younger individuals. The number of individuals composing the past population studied here could suggest that the occupied environment was open due to comparisons to populations of extant elephants. We consider this population as an aggregation of family units, which suggests a time of low environmental humidity. Based on literature and our findings, their extinction appears to be regional and probably related to a catastrophic event.