We studied bird distributions on 15 small patches of subtropical rainforest, ranging from 0.08 to 2.5 ha, in north-eastern New South Wales. Three-quarters of the bird species found in an extensive area of nearby rainforest were recorded in one or more of these isolated patches. Species that were not recorded, generally were rare in the extensive forest or are characterized by large home ranges. Several species more typical of open country were also found in the isolated patches. The number of resident species per patch ranged from one to 19; these were added in a rather predictable order from small to larger areas. Additional species observed in the patches either were transient or had home ranges encompassing several discontinuous areas. Although area is the best single predictor of species richness, isolation, disturbance by livestock and distance from water all tend to reduce the number of resident bird species. We propose that high dispersal abilities of rainforest birds near Dorrigo reflect the geographical and palaeogeographical distribution of Australian rainforest. The small total area and discontinuity of original tracts of rainforest, perhaps accentuated during the Pleistocene, have generally prevented persistence or colonization of highly sedentary, specialized bird species.

Acacia pycnantha, like many members of its genus, produces nectar from a gland at the base of the petiole. Nectar is apparently produced only when the plant is flowering and only on petioles close to the inflorescences. The nectary seems poorly placed to attract insect pollinators, but honeyeaters and silvereyes take the nectar, brush against the flowers and could effect pollination. Insects also visit the nectaries and flowers and may act as an additional attractant to the birds.

'New Holland honeyeaters Phylidonyris novaehollandiae moult their primary feathers between mid- October and late April. Most adults probably have completed their moult by February, some immatures moult later. Individual birds may take over 100 days to complete moulting their primaries. The secondary and tail feathers are moulted towards the end of the primary moult and slightly after it. Limited data for 15 other species suggest that they moult at a similar time and for a similar duration. Breeding, in the Adelaide area, occurred in all months of the year in at least some species of honeyeaters, with a major peak from July to November, and a minor peak in April and May. Insectivorous species breed somewhat later than nectarivorous species and breed less often in autumn. Breeding of the former group may be influenced chiefly by increasing temperature in spring, whereas autumn rainfall probably influences the timing of peak nectar production. Although there is some overlap between the extensive breeding seasons and moulting periods of honeyeaters I have no evidence that individual honeyeaters breed while they are moulting.