The Maintenance Nitrogen Requirements of the Queensland Blossom Bat (Syconycteris australis) on a Sugar/Pollen Diet: Is Nitrogen a Limiting Resource?

(Uploaded by Plazi for the Bat Literature Project) TheQueensland blossombat (Syconycterisaustralis) is a specialist nectar and pollen feeder. Its dietary maintenance nitrogen requirement(MNR),determined byfeeding blossombats varying levels ofpollen in an artificialsugar solution, was 337 mg N * kg-a . d-'. Thisis similar to nitrogen requirementspredicted from the standard metabolic rate of blossombats.Dry-matterdigestibility(79%89%) andpartial apparent nitrogen digestibility(58%-97%) was highfor the sugar/pollen diet. Dry-matterintake was not correlated withdietary nitrogen as previouslypredictedforpteropodids. Althoughpollen is a rich source of dietary nitrogen, it is a highlydispersedfood source. On the basis of nitrogen content of Banksiapollen and mean pollen standing crops(27 + 2pollen bundlesper inflorescence, N = 128) Ipredict that many Banksiainflorescences(36-48) need to be visited each night to satisfytheMNRof an 18-g blossombat. Even moreBanksia inflorescences(28-62) must be visited nightlyto satisfyallometricallypredicted energy requirementsof blossombats on the basis of mean Banksiaenergy standing crops(1.2 + 0.1 kJper inflorescence,N = 128). Previous interpretations of nitrogen as theprimary limiting nutrient toflyingfoxes may need to be reconsideredfor thosespecies thatsupplementtheirdiet withpollen.