RELATIONSHIP BETWEEN NECTAR PRODUCTION AND YEARLY AND SPATIAL VARIATION IN DENSITY AND NESTING OF RESIDENT HONEYEATERS IN HEATHLAND NEAR SYDNEY

The maximum density of resident honeyeaters in heathland near Sydney w as very similar from one area and year to another, despite large varia tion in production of nectar-energy. The most likely explanation for t his is that density is determined by the spacing behaviour of birds ra ther than by nectar production or other factors. Within years, nesting by these residents was positively correlated with temporal variation in production of nectar-energy and 90% of nesting occurred when the es timated average amount of energy available in the heathland per pair e xceeded that required to support parents and young. Most nesting and t he highest nectar production consistently occurred between April and J uly.