He subsequently spent three years at the University of Otago in New Zealand where he began what was to become an enduring focus of research, the behavioural ecology of Silvereyes and other species of Zosterops.
Fruit eaten by a large variety of birds; including Brown Cuckoo Dove, Australasian Figbird, Green Catbird, Lewin's Honeyeater, Olive-backed oriole, Pied Currawong, Paradise Riflebird, Rose Crowned Fruit Dove, Silvereye, Superb Fruit Dove, Topknot Pigeon and Wompoo Fruit Dove.
The decline of the White-chested White-eye began as the introduced Silvereye (Zosterops lateralis) became naturalized on Norfolk Island.