In October-November 1992 the island of Mangaia, Cook Islands, was surveyed for Tanga’eo (Halcyon tuta ruficollaris). The Tanga’eo was found to be primarily a forest bird, preferring continuous forest canopy. Its abundance was influenced by forest type, extent, and degree of habitat modification. A number of potential threats to the survival of Tanga’eo were identified including habitat loss and disturbance by Common Mynas (Acridotheres tristis). A brief survey of rodents was carried out. Although the Tanga’eo population was estimated to have been between 250 and 450 birds, low numbers of birds in apparently suitable forest in the southwest of Mangaia indicate that further research is needed to determine population trends and conservation requirements.