Threshold model of feeding territoriality: a test with an Hawaiian honeycreeper

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.A cost-benefit model predicting threshold requirements for establishment of feeding territories in nectarivorous birds was tested by comparing 24-hour energy production of nectar with energy budgets in territorial and nonterritorial Hawaiian honeycreepers. The test was positive and demonstrated that nectar productivity was more important in determining establishment of territories than intrusion pressure and floral dispersion.Supported by NSF Grant GB-23230, Island Ecosystems IRP/lBP Hawaii, and a grant from the American Philosophical Society to F. L. Carpenter. The Primo Foundation has continued its essential support