Rapa shearwater explained

The Rapa shearwater (Puffinus myrtae), is a rare seabird of the tropics from the family Procellariidae. It breeds on the surrounding islets of Rapa in the Austral Islands of French Polynesia where it is known locally as the kaki kaki.^[1]

The Rapa shearwater was first described in 1959 as a subspecies of the little shearwater.^[2] The holotype was later found to be a juvenile and an adult specimen was described in 2017.^[3]

A 2015 genetic study using DNA sequences of the mitochondrial cytochrome b gene, found that the Rapa shearwater is sister to a clade containing the Hawaiian shearwater (Puffinus newelli) and the little shearwater (Puffinus assimilis).^[4] Morphological data supports this relationship but the Rapa shearwater is much smaller than the other two species.^[3]

Not much is known about its decline. It most likely once occurred on Rapa itself, though this population has been extirpated by the polynesian rat, feral goats, and feral cats.

Notes and References

1. The Ornithological Society of Polynesia
2. Bourne . W.R.P. . 1959 . A new little shearwater from the Tubaui Islands: Puffinus assimilis myrtae subsp. nov. . Emu . 59 . 3 . 212–214 . 10.1071/MU959212. 1959EmuAO..59..212B .
3. Shirihai . H. . Schweizer . M. . Kirwan . G. . Bretagnolle . V. . 2017 . The type of Rapa Shearwater Puffinus (newelli?) myrtae from the Austral Islands, Polynesia, with remarks on the morphological variation of the taxon . Bulletin of the British Ornithologists' Club . 137 . 2 . 127–134 . 10.25226/bboc.v137i2.2017.a11 .
4. Martínez-Gómez . J.E. . Matías-Ferrer . N. . Sehgal . R.N.M. . Escalante . P. . 2015 . Phylogenetic placement of the critically endangered Townsend's Shearwater (Puffinus auricularis auricularis): evidence for its conspecific status with Newell's Shearwater (Puffinus a. newelli) and a mismatch between genetic and phenotypic differentiation . Journal of Ornithology . 156 . 4 . 1025–1034 . 10.1007/s10336-015-1189-2. 254157285 .