Habitat Relationships and Conservation of the Yellowhead

The yellowhead, a forest-dwelling passerine endemic to the South Island of New Zealand, has declined in both abundance and range since the arrival of European settlers last century. In the last 30 years it has all but disappeared from the northern half of the South Island but remains widespread in the south. One possible explanation is that the yellowhead has declined in abundance throughout its range, disappearing from less suitable habitats in which it was never very abundant. To test this hypothesis a habitat suitability index was constructed and northern and southern forests compared. Yellowheads appear to be tall forest specialists and are most common in tall red beech dominated forests at low altitude on flat valley floors. No evidence was found that forests in the northern South Island are any less suitable for yellowheads than those in the south. Other explanations for the decline of yellowheads in the north of their range are discussed.