RANGE SIZE AND DENNING BEHAVIOUR OF BROWN KIWI, APTERYX AUSTRALIS MANTELLI, IN HAWKE'S BAY, NEW ZEALAND

Twelve kiwis were radio-tagged and tracked for 12-78 weeks in two sites in Hawke's Bay. Four bonded pairs had ranges of 19.1 to 42.3 ha (estimated by the convex polygon method), which were apparently defended against other kiwis. Two unmated females had ranges of 48.0 and 43.1 ha. Another unmated female occupied a narrow, circular strip, 5.4 km long, covering about 26 ha. The ranges of four kiwis in scrubland and eight in climax beech/podocarp forest were similar in size. Kiwis roosted on 36% of days in burrows which they excavated themselves. On other days they roosted in natural subterranean tunnels, or in hollows under fallen trees, thick vegetation, or inside logs. Generally they roosted in a different place each day but often returned to sites they had used previously. Members of bonded pairs roosted apart on 92% of days, in different parts of their range. In terms of current understanding of population genetics, reserves for kiwis in Hawke's Bay probably need to be at least 7500 ha in order to support a genetically enduring population of 250 breeding pairs. None of the existing reserves meet this requirement.