Niche occupancy in south-eastern Brazilian tadpole communities in montane-meadow streams

Abstract

Microhabitat use by tadpole species was investigated in streams of montane meadows of the Serra do Cipó, south-eastern Brazil. Microhabitats were classified into 24 types based on water depth, current, aquatic vegetation and substrate type, and quantified in 16 streams. A total of 844 tadpoles from 19 species was recorded, as well as microhabitat types used. Tadpoles, from all species pooled, used microhabitat types in the proportions available in the set of sampled streams. Diversity of microhabitats used was considered as a measure of niche breadth for tadpoles, and microhabitat diversity in streams was interpreted as available niche space. For the most part, species used microhabitats in different proportions, and conspecifics differed in microhabitat use among different streams. Neither niche breadths nor niche overlaps of tadpoles could be related to the number of species occupying streams. Thus not all available niche space may be occupied by tadpole species. More generalist species (those with broader niches) did not generally occupy more streams. Behavioural flexibility of tadpoles in microhabitat use may be a response to the unpredictability of the montane-meadow stream habitat. The role of adult anurans in choosing oviposition sites may also influence the distribution of tadpole species among streams.

Distribuição temporal e diversidade de modos reprodutivos de anfíbios anuros no Parque Nacional das Emas e entorno, Estado de Goiás, Brasil

“…Alternativamente, a distribuição temporal e a abundância dos girinos pode estar relacionada com a distribuição do esforço reprodutivo dos anuros adultos (e.g. INGER et al, 1986;ETEROVICK & BARROS, 2003;KOPP & ETEROVICK, 2006 Além disso, a sazonalidade quanto à precipitação poderia contribuir para a maior ocorrência de espécies com o modo reprodutivo 1, seguido dos modos 11 e 30 pois, segundo INGER & COLWELL (1977), ambientes abertos tendem a ser menos previsíveis e estáveis em relação às condições climáticas se comparados com ambientes florestais. SANTOS et al (2008), em estudo realizado em área aberta (bioma Pampa) na região sul do Brasil, também encontraram maior número de espécies com modos 1, 11 e 30.…”

Bioacústica e sítio de vocalização em taxocenoses de anuros de área aberta no noroeste paulista

“…Apesar de vários estudos criticarem o modelo de equilíbrio em comunidades (e.g., Strong 1982, Strong et al 1984, Wiens et al 1986, Eterovick & Barros 2003 alguns artigos recentes têm demonstrado coexistência baseada em diferenciação de nicho (e.g., Elliot & Mariscal 2001, Menin et al 2005, Verburg & Bills 2007, inclusive entre espécies crípticas (Nicholls & Racey 2006, Wellborn & Cothran 2007.…”

Macroinvertebrates as tadpole food: importance and body size relationships

“…Because of their aquatic/terrestrial life cycle, amphibians are exposed to ecological changes in both environments (BRANDÃO & ARAÚJO 2002). Water quality changes caused by insecticides and fertilizers contaminations, drainage of mining areas, and vegetation burns beyond the riparian zones are examples of alterations that can decrease amphibians diversity (ETEROVICK & BARROS 2003).…”

“…Others consider species distribution in ponds as a consequence of food availability and influence of feeding strategies among tadpoles of different sizes (ALFORD & CRUMP 1982, DIAZ PANIAGUA 1985, ETEROVICK & BARROS 2003.…”