Mohoua is a genus of small birds comprising three species endemic to New Zealand, named after the Māori word for one of its members, the yellowhead. Originally classified in the whistler family, Pachycephalidae, a 2013 study suggested they merited their own family, Mohouidae, which was supported by genetic research in 2019 linking them closely to the Neosittidae family of sittellas. These birds exhibit sexual dimorphism, with larger males, and are known for their gregarious nature, especially outside the breeding season, when they often forage in mixed-species groups and can form the nucleus of such flocks. Mohoua species practice cooperative breeding, particularly in whiteheads and yellowheads. They are the exclusive host species for the long-tailed cuckoo's brood parasitism. The genus, introduced by René Lesson in 1837 with the yellowhead as the type species, includes the whitehead (Mohoua albicilla) on the North Island, the pipipi or New Zealand brown creeper (Mohoua novaeseelandiae) on the South Island, and the yellowhead (Mohoua ochrocephala) also found on the South Island.