The Significance of Pollen in the Diet of the New Holland Honeyeater, Phylidonyris Novaehollandiae (Aves : Meliphagidae).

Abstract

New Holland honeyeaters obtain negligible nutriment from pollen. Three lines of evidence show that the contents of pollen grains are not extracted during passage through the birds. Firstly, the proportion of empty pollen grains in faecal samples did not differ from that in samples of pollen dusted off the facial feathers of wild birds. Secondly, the proportion of empty pollen grains in samples taken at successive points along the alimentary canal from oesophagus to cloaca did not change in the 10 birds examined. Finally the condition of pollen fed to caged birds did not change with passage through the birds. Quantities of pollen ingested by honeyeaters are small, around 300,000 pollen grains or 15 mg of pollen per day. Even if fully digested this uould provide only a small proportion of the birds' protein requirements and a negligible amount of energy. Pollen is probably collected accidentally while the birds collect nectar from flowers.