Current view: Data table and detailed info
Taxonomic note
Puffinus newelli (del Hoyo and Collar 2014) has been split into P. newelli and P. myrtae (Handbook of the Birds of the World and BirdLife International 2018). Martínez-Gómez et al. (2015) found that P. (n). myrtae, ‘Rapa Shearwater’, is genetically more distinct from newelli than newelli is from auricularis. On this basis they propose that myrtae be treated as a full species. Such an arrangement is supported by Shirihai et al. (2017), who noted:
'Rapa Shearwater is much smaller (in all biometric characters) than the other two taxa…, and is furthermore highly distinctive in having a unique combination of white undertail-coverts (vs. dark in both newelli and auricularis) and whitish inner webs to the remiges, as well as a white face.'
Following revised scoring of parsed characters for the differentiation of P. auricularis, P. newelli and P. myrtae, the latter emerges as a very strong candidate for species rank, given that the effect size for wing length vs the smaller of the other two taxa (auricularis), based on Table 3 in Shirihai et al. (2017), is –6.56 (score 3); white vs dark undertail-coverts (at least 2); whitish inner webs to the remiges (at least 1); and a ‘white face’ (impossible to interpret, and in fact not apparent in several photographs online).
We will seek to confirm the characters identified as distinctive by Shirihai et al. (2017) but accept the strong likelihood of at least minor vocal differentiation. Allowing 1 for such an eventuality, and having a score of 6 already on morphological grounds, we tentatively accord myrtae species status as Rapa Shearwater.
Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Handbook of the Birds of the World and BirdLife International. 2018. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 3. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v3_Nov18.zip.
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. J. Orn. 156: 1025-1034.
Shirihai, H., Schweizer, M., Kirwan, G. M. & 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. Bull. Brit. Orn. Club 137: 127-134.
IUCN Red List criteria met and history
Red List criteria met
Red List history
Migratory status |
full migrant |
Forest dependency |
medium |
Land-mass type |
|
Average mass |
- |
Population justification: In 1974 the population size was estimated at 265-380 pairs (excluding any potential birds breeding on the main Rapa Island), but no individuals were located during surveys in 1989 (Thibault and Varney 1991). A survey of Morotiri found no individuals of this taxon (Gaskin et al. 2006), and a visit to Rapa in 2017 found only a very small number of individuals (though this was likely not during the breeding season) (S. Cranwell per M. O’Brien in litt. 2018). At sea surveys find the occasional individual, but it appears highly unlikely that there 500-800 mature individuals remaining (M. O’Brien in litt. 2018). The population size is tentatively placed in the band 50-249 mature individuals, equating to 75-375 individuals in total, although it potentially could be lower than this.
Trend justification:
While it is likely that the threats this species faces are causing declines, there is no clear evidence of the rate of decline.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Rapa Shearwater Puffinus myrtae. Downloaded from
https://datazone.birdlife.org/species/factsheet/rapa-shearwater-puffinus-myrtae on 08/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 08/12/2024.