The mewing kingfisher or Mangaia kingfisher (Todiramphus ruficollaris), known locally as the tanga‘eo, is a species of bird in the Alcedinidae, or kingfisher family. It is endemic to Mangaia in the Cook Islands. Its natural habitats are subtropical or tropical moist lowland forests and plantations.
The mewing kingfisher is in length, with a large head and large black bill. Similar to some other Todiramphus kingfishers, it has blue-green upper-parts, with a yellow-orange collar and head-band, and a blue-green cap. The under-parts are white.
It is threatened by habitat loss and by disturbance by introduced common mynas at its nesting hollows. The Taporoporo'anga Ipukarea Society, BirdLife International's partner organisation in the Cook Islands, has proposed a program to eradicate the mynas from Mangaia.