Within-Territory Division of Foraging Space by Male and Female Amakihi (Loxops virens)

Kamil, Alan; Van Riper, Charles

Whenever a foraging nectarivorous bird visits a flower that contains no nectar, it has wasted time and energy. Therefore, one would expect nectar-feeding birds to minimize visits to flowers that were recently depleted of nectar. An individual bird can forage more efficiently by excluding intruders from a feeding territory and not revisiting flowers within the territory. This pattern of behavior occurs in sunbirds (Gill and Wolf 1977), some hummingbirds (Gass and Montgomerie 198 1), and honeycreepers (Kamil 1978). When a breeding pair of nectar feeders maintains a nesting and feeding territory, it may be important for one member to avoid flowers recently depleted of nectar by its mate. Amakihi (Loxops virens) are nectar-feeding Hawaiian honeycreepers that maintain type A territories within which copulation, nesting, and foraging occur (Hinde 1956), and from which conspecifics are excluded (van Riper 1978). Within these territories, individuals avoid flowers from which they have recently taken nectar (Kamil 1978). In this paper, we present data which suggest that pairs of honeycreepers subdivide their territories while foraging, and that this division ceases as the female spends less time at the nest.

Within-Territory Division of Foraging Space by Male and Female Amakihi (Loxops virens)

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