Feeding ecology of kereru; (Hemiphaga novaeseelandiae) in podocarp–hardwood forest, Whirinaki Forest Park, New Zealand

The diet and food preferences of the kererū (Hemiphaga novaeseelandiae) were studied in Whirinaki Forest Park, central North Island, New Zealand, during February 2000 – March 2001. The study was carried out in two areas of podocarp–hardwood forest, Oriuwaka (1750 ha) and Otupaka (1830 ha). Fruit dominated in the diet at both sites (65% in Oriuwaka, 87% in Otupaka), but there were seasonal changes. Foliage and flowers were more important in the diet in winter and spring, but the timing of the switch from fruit to foliage differed between the areas. The main fruit eaten also changed seasonally from tawa (Beilschmiedia tawa) in early summer to miro (Prumnopitys ferruginea) in late summer and autumn. Variation in diet partly reflected seasonal phenology of the plants and differences in vegetation between the two areas, but when food-type availability is considered, kererū showed selective preference for some food types at some times. Miro and tawa fruits were highly preferred food types in both areas. This study highlights the likely need of kererū to have access to various vegetation types in order to meet their seasonally changing nutritional requirements in a podocarp–hardwood forest where the availability of food, especially fruits, can differ markedly both in time and space. Thus, large forest blocks that contain a variety of habitat types, or landscapes containing patches of various habitat types, are needed for the long-term conservation of kererū populations.