FORAGING, SEASONALITY AND NESTING OF SEYCHELLES SUNBIRDS NECTARINIA DUSSUMIERI

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SummaryForaging and breeding behaviour of Seychelles Sunbirds Nectarinia dussumieri was studied for a total of four months on six islands in the Seychelles.Birds obtained nectar from indigenous and introduced plants directly (inserting the bill into the corolla‐tube), perched or hovering, or indirectly (piercing the corolla). Direct methods were used in plants with corolla‐tubes less than 20 mm (the length of birds' bills) and indirect methods in most longer flowers. Flowers with longer corolla‐tubes appeared to be preferred. In feeding groups, birds fed more rapidly if not involved in aggressive interactions, which may reflect defence of feeding areas.Insects were taken from the foliage of indigenous and introduced trees, using a variety of techniques. Flycatching was most prevalent in small‐leaved species, and upright probing in large‐leaved species. In Calophyllum inophyllum, which held very high densities of insects, hovering was used only in saplings, while other methods were used in both mature trees and saplings.The percentage of nests that were active declined from September to December‐January, suggesting a peak of breeding during this period, the first part of the northwest monsoon season. Examination of live birds and museum skins showed that wing‐moult occurs chiefly from January‐May, but males on Praslin also moult in August‐September.Nests varied in conspicuousness, being best hidden on Mahé and Silhouette, the only islands with populations of Seychelles Kestrels Falco araea. Males contributed to the earliest stages of nest building, but all later building, as well as all incubation and most feeding of young was done by females. Both sexes defended the nest area against other birds, especially those attempting to steal nest material. Males advertized by song from prominent perches near nests; females also sang occasionally.Males are larger in most dimensions than females, but no inter‐island differences were found. The species may have evolved duller plumage and larger size than related species, but this remains uncertain without further evidence on its origins. The clutch of one egg only represents a reduction from the normal clutch size of local mainland congeners.