Pachycephalidae

The family Pachycephalidae, collectively the whistlers, includes the whistlers, shrike-thrushes, shrike-tits, pitohuis and Crested Bellbird, and is part of the ancient Australo-Papuan radiation of songbirds. Its members range from small to medium in size, and occupy most of Australasia. Australia and New Guinea are the centre of their diversity, with species and genera also reaching New Zealand, and in the case of the whistlers, the South Pacific islands as far as Tonga and Samoa and parts of Asia as far as India. The exact delimitation of boundaries of the family are uncertain, for example the genus Mohoua, which is endemic to New Zealand has been placed with the family based on a number of morphological features and DNA-DNA hybridization studies, but the placement is still controversial.