The Cerrado encompasses ca. 2 million km 2 in Brazil. Most Cerrado areas have been greatly disturbed in the past decades. Only 20% of this biome remain undisturbed, and only 1.2% is protected. Knowledge on the biology and diversity of Cerrado amphibian assemblages is still incipient. Here we present natural history information (habitat use and reproductive activity) of 28 species of frogs from the Estação Ecológica de Itirapina (EEI), and compare the composition of this assemblage with those of other Cerrado areas, other open areas, and a few forest areas throughout Brazil. We demonstrate that the Itirapina assemblage is more similar to those of other open areas than to those of forests, even when the latter are geographically closer. Six species occurred in the gallery forest at varying levels of dependence (three independent, two semidependent, and one totally dependent) while all other species occurred exclusively in open areas. For most species at EEI, reproduction was strongly synchronized with the onset of the rainy season, with the exception of Hypsiboas lundii, which called throughout the year, and Proceratophrys sp. which started calling prior to the beginning of the rainy season. The spatial and temporal patterns observed in this assemblage seem to reflect both ecological (e. g. hydroperiod of water bodies) and historical factors (e. g. early breeding in leptodactylids, late breeding in hylids, both phylogenetically constrained). Key words: Amphibians; Habitat use; Reproduction; Cerrado; Itirapina; São Paulo; Brazil Resumo O Cerrado originalmente ocupava dois milhões km 2 no Brasil. Nas últimas décadas, as áreas naturais de Cerrado vêm sendo destruídas rapidamente. Somente 20% da região original permanece inalterada e apenas 1,2% encontram-se em unidades de conservação. O conhecimento sobre a biologia e a diversidade de espécies de Cerrado ainda são muito escassos. Neste trabalho, nós apresentamos informações sobre história natural (uso do ambiente e atividade reprodutiva) de 28 espécies de anfíbios da Estação Ecológica de Itirapina (EEI) e comparamos a composição das taxocenoses da EEI com aquelas de outras localidades de Cerrado, e também de áreas florestais e outras fisionomias abertas. Demonstramos que a taxocenose de Itirapina assemelha-se mais àquelas de outras formações vegetais abertas, estruturalmente mais semelhantes, do que as taxocenoses de formações florestais, mesmo que estas sejam geograficamente mais próximas. Seis espécies ocorreram nas matas de galeria em diferentes graus de dependência (três independentes, duas semi-dependentes e uma totalmente dependente) enquanto que as demais ocorreram exclusivamente nas fisionomias abertas. Para a maioria das espécies da EEI, a reprodução foi fortemente sincronizada com a estação chuvosa, com exceção de H. lundii, que vocalizou durante todo o ano e Proceratophrys sp. que iniciou as atividades de vocalização antes do início da estação chuvosa. Os padrões espacial e temporal observados nessa taxocenose parecem refletir tanto fatores ecol...
Abstract Kiefer, M.C., Van Sluys, M. and Rocha, C.F.D. 2007. Thermoregulatory behaviour in Tropidurus torquatus (Squamata, Tropiduridae) from Brazilian coastal populations: an estimate of passive and active thermoregulation in lizards. -Acta Zoologica (Stockholm) 88 : 81-87Geographical variation in the degree of thermoregulatory behaviour of the lizard Tropidurus torquatus was studied in 10 restinga populations along approximately 1500 km of Brazilian coast. An index of thermoregulation was estimated using the difference between body and environmental (air and substrate) temperatures and the percentage of negative values for these differences (proportion of body temperatures lower than environmental temperatures). In most populations, the lizards primarily used active thermoregulation, through behavioural means, and mainly in relation to substrate temperatures. Along the restingas, the degree of active thermoregulation increased as a function of the increase in the local environmental temperatures along the restingas. Behavioural thermoregulation of T. torquatus helps the lizards to maintain their body temperatures within an optimal range in which to perform their normal daily activities.
The tropidurid lizard Tropidurus torquatus (Wied, 1820) has a set of populations inhabiting coastal sand dune habitats (“restinga”) along the eastern Brazilian coast. Despite its wide geographic range, there is no information about geographic variation in reproductive features among its populations. In the present study we compared some reproductive aspects of females in 10 coastal populations of T. torquatus, aiming to evaluate to what extension they vary geographically. The minimum size at maturity was relatively similar to most populations, but mean female body size had a considerable variation. Clutch size of almost all coastal populations of T. torquatus had little variation and was composed predominantly of two eggs. Interpopulational variation in the mean egg volume was relatively wide and strongly influenced by the variation in mean female body size. The data of the present study indicated that females of almost all coastal populations of T. torquatus produce, predominantly, clutches with two eggs and invest more energy in egg size instead of clutch size, probably as a consequence of morphological and environmental factors. The increased reproductive investment in egg size was confirmed by the values obtained for the relative clutch mass, which remained relatively constant along the coastal geographic distribution of T. torquatus.
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