Bird ecology in temperate rainforest

Temperate rainforest, dominated by species of Nothofagus, the Antarctic Beech, occurs in South America, Australia and Tasmania, New Zealand, and in New Guinea and some south-west Pacific Islands. In Tasmania both habitats types and bird species are distributed along a xeric-mesiic gradient. The relationships between the habitats have been established by similarity analysis. The number of bird species decreased along the xeric-mesic gradient and no species is restricted to temperate rainforest. Bird species diversity, equitability, dominance index and relative bird density have been determined along this gradient and the effect of foliage height diversity and per cent vegetation cover has been studied. Temperate rainforests in Chile, Tasmania and New Zealand have comparable bird species diversities, equitabilities and dominance indices. The one Patagonian site for which data are available appears to be atypical. The structure of the Tasmanian temperate rainforest bird community, which consists of more species than hitherto reported, was determined from measurements of patch preference, vertical stratification and feeding behavior. a sequential method, which can include any number of niche dimensions, was used to determine niche structure and was applied to temperate rainforest communities in other regions. Similarities in niche occupation patterns in Fagus-Acer and Nothofagus forests are high and show evidence of parallel evolution. There is considerable evidence that Nothofagus forests generally have never been important as a source of bird species and have been unimportant in the evolution of the class.