A detailed description of the breeding season of a community of birds on the south-east coast of Australia

The details of a breeding season have been investigated and described for many bird species and groups of species, but rarely for an entire breeding community. The collection of such data is the only way of quantifying the number of birds a habitat can support, how many fledglings it can produce, and the avian diversity that can exist in the habitat. Without these quantitative and qualitative measures, the significance of particular habitats for avian conservation is difficult to assess. We have accumulated comprehensive data on a breeding bird community on a 10 ha site for eight seasons, which has enabled us to condense the many aspects of breeding into an ‘average’ breeding season. The breeding community consisted of 44 species, which used all of the site for nesting. Some species bred each season, while others bred as infrequently as once in the eight seasons. Nesting occurred between the beginning of August and the end of January, different species showed markedly different starting and finishing times, and there were different temporal patterns of breeding within the breeding periods of the different species. The number of pairs that bred on the site varied each season, a pattern that we have previously shown to be related to the value of the Southern Oscillation Index before the start of the season. Nest success rates varied considerably between species, but the overall success rate on the site was approximately 50%. We estimate that the spotted gum forest habitat on the south-east coast of Australia (1200 km2) produces approximately 1.5 million fledglings each season.