The feeding ecology and habitat use of kereru and bellbird in a modified forest remnant, South Canterbury, New Zealand

Abstract

The use of exotic and native plant species for feeding and habitat use by kereru (Hemiphaga movaeseelandiae) and bellbird (Anthornis melanura) were investigated from February to June 1998 at Waihi Bush, a modified forest remnant in South Canterbury. Kereru and bellbird feeding patterns varied seasonally and closely reflected changes in plant phenology. For both species, a decline in the amount of fruit taken from autumn to winter paralleled a decline in fruit availability. Although exotic plants comprised only 4.3% of the basal area at Waihi Bush, they were used in 18.4% and 12.6% of total observations for kereru and bellbird respectively. Exotic plants were used most extensively by kereru in February and bell bird in March, coinciding with a high availability of fruit on exotic compared with native plant species at that time.

Selection analyses revealed that kereru and bellbird were positively selecting some plant species while avoiding others. This allowed the identification of important plant resources, including pate (Schefflera digitata) for kereru and red matipo (Myrsine australis) for bellbird. Ash (Fraxinus excelsior) was the only exotic plant highly selected by kereru and bellbird. Overall, there was a high variation in plant selection, consistent with the idea that kereru and bellbird are habitat generalists, both using more than 75% of the plant species present. This generalist attribute suggests exotic plant removal is unlikely to limit the foods or habitat available to kereru or bellbird during autumn and winter. The implications of this research for the management of exotic trees in forest remnants are discussed.