Onychoprion

Onychoprion, the "brown-backed terns", is a genus of seabirds in the tern family. Although the genus was first described in 1832 by Johann Georg Wagler the four species in the genus were until recently retained in the larger genus Sterna, the genus that most terns are in (Bridge et al., 2005).

Three of the four species are tropical, and one has a sub-polar breeding range. The Sooty Tern has a pan-tropical distribution; the Bridled Tern also breeds across the Tropical Atlantic and Indian Ocean but in the central Pacific it is replaced by the Spectacled Tern. The Aleutian Tern breeds around Alaska and Siberia but winters in the tropics around South East Asia.

• Genus Onychoprion – "brown-backed" terns.
  • Spectacled Tern, Onychoprion lunatus
  • Bridled Tern, Onychoprion anaethetus
  • Sooty Tern, Onychoprion fuscatus
  • Aleutian Tern, Onychoprion aleuticus

Manutara is the Rapa Nui language name for Spectacled and Sooty Terns. Both arrive at Easter Island and hatch their eggs on the island called Motu Nui, an event that was used for an annual rite called Tangata manu.

References

• Bridge, E. S.; Jones, A. W. & Baker, A. J. (2005): A phylogenetic framework for the terns (Sternini) inferred from mtDNA sequences: implications for taxonomy and plumage evolution. Molecular Phylogenetics and Evolution 35: 459–469. PDF fulltext
• Collinson, M. (2006). Splitting headaches? Recent taxonomic changes affecting the British and Western Palaearctic lists. British Birds 99(6): 306-323.