Habitat use and foraging behaviour of Mohua (Mohoua ochrocephala) in the podocarp forest of Ulva Island, New Zealand

Abstract

The Mohua (Mohoua ochrocephala) is an endangered forest passerine endemic to New Zealand. We examined the habitat use and behaviour of Mohua in podocarp forest after their reintroduction to Ulva Island to determine the suitability of this forest type. When in podocarp forest mohua spent <75% of their time foraging, less than when in beech forest (90%). This suggests that podocarp forest provides more food resources than beech forest and is suitable for Mohua. The birds were frequently observed in the coastal scrub surrounding the island, but this habitat type was not used for foraging. We discovered a seasonal variation in foraging patterns: ripping through bark and epiphytes was predominant in spring, and gleaning in the foliage prevailed in summer. Miro, Rata and Rimu were the preferred foraging trees in the interior forest, and Hall's Totara and Kamahi were consistently avoided in both the forest and along the coast. Variation in the use of tree species throughout the season suggests that a structurally diverse forest community is an important habitat requirement for Mohua, as it provides sufficient resources for all seasons.