Status and feeding of the Eastern Spinebill Acanthorhynchus tenuirostris at the New England National Park, North-eastern NSW

Abstract

The Eastern Spinebill is the commonest bird at a site, primarily in dry sclerophyll forest, at 1,500 m in north-eastern New South Wales. Three other species of honeyeaters are common and seven other species occur. There is a large influx of Spinebills in autumn, which coincides with the start of flowering of Banksia collina, the nectar of which is a major source of energy during winter. Numbers fall again in spring as B. collina flowers decline. Banksia integrifolia is an important nectar source in autumn and flowers of Epacris longiflora, Streptothamnus beckleri, Meullerina celastroides and Amyema sp are also visited. We found little evidence of breeding at the site, most juveniles were caught in summer. Spinebills moult in autumn. They are heavier in winter and have more visible fat.

Only 6% of Spinebills that were banded were recaptured, those banded in summer being more likely to be recaptured. The daily production of nectar at peak flowering of B. collina (26,000 kJ/ha) is as high as any found elsewhere in south- eastern Australia. In most of other sites where nectar is prolific medium-sized or large honeyeaters are common. The abundance of the small Spinebills at this rich site is hard to explain.