Birds were counted in the montane Ohikanui Valley and nearby at the mouth of the Buller Gorge in all four seasons of the year. Counts from these areas are compared with those from three sites previously studied in the much larger and broader Inangahua Valley in the same region. The effect of topographic temperature inversion on the deep and glaciated Ohikanui Valley is reflected in the pattern of vegetation and also in the altitudinal and spatial distribution of the birds. Large differences between the seasonal patterns of occurrence of some species of birds in the Ohikanui and Inangahua Valleys are demonstrated. Reasons for these differences are examined, such as seasonal migration in and out of the Ohikanui Valley for species such as Tui (Prosthemadera novaeseelandiae), Bellbird (Anthornis melanura), and Silvereye (Zosterops lateralis) and altitudinal movement by species such as Rifleman (Acanthisitta chloris) and Grey Warbler (Gerygone igata).  The study emphasises the importance of warm, floristically rich, lowland forest for the winter maintenance of honeyeater populations which breed in the montane valleys.