This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for passerines
Lynx Edicions and BirdLife International will soon publish the second volume of the HBW-BirdLife Illustrated Checklist of the Birds of the World, building off the Handbook of the Birds of the World series, and BirdLife’s annually updated taxonomic checklist.
The new Checklist will be based on the application of criteria for recognising species limits described by Tobias et al. (2010). Full details of the specific scores and the basis of these for each new taxonomic revision will be provided in the Checklist.
Following publication, an open and transparent mechanism will be established to allow people to comment on the taxonomic revisions or suggest new ones, and provide new information of relevance in order to inform regular updates. We are also actively seeking input via a discussion topic here regarding some potential taxonomic revisions that currently lack sufficient information.
The new Checklist will form the taxonomic basis of BirdLife’s assessments of the status of the world’s birds for the IUCN Red List. The taxonomic changes that will appear in volume 2 of the checklist (for passerines) will begin to be incorporated into the 2016 Red List update, with the remainder to be incorporated into subsequent Red List updates.
Preliminary Red List assessments have been carried out for the newly split or lumped taxa. We are now requesting comments and feedback on these preliminary assessments.
Nukupuu Hemignathus lucidus is being split into H. lucidus, H. affinis and H. hanapepe, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, H. lucidus was listed as Critically Endangered (Possibly Extinct) under criterion D, on the basis that the last confirmed sightings were in the 1990s on Maui with none since then despite extensive effort (BirdLife International 2016). However, until further surveys have shown beyond reasonable doubt that the species is extinct the species was considered extant, and if the species does remain its population would be tiny (<50 mature individuals) (BirdLife International 2016). H. lucidus (as now defined following the taxonomic change) was only known from the Hawaiian island of O’ahu, but it is thought to have gone extinct in the mid 1800s, with collectors finding no trace of it in the 1890s (Munro 1960). It is therefore thought that this species is no longer extant, and so warrants listing as Extinct.
H. affinis has only been recorded on the Hawaiian island of Maui in wet ohia forest and mesic ohia-koa forest (Pratt 2016a). It may have historically been found across the island but more recent possible records are restricted to the eastern and north-eastern slopes of Haleakala Volcano (Pratt 2016a, BirdLife International 2016). There were unconfirmed reports between the 1960s and 1990s including one male seen in 1995 by multiple qualified observers with detailed field notes (Pratt and Pyle 2000). Pratt (2010) suggests that a few of these reports, from the Hanawi Natural Area Reserve, seem credible although other authors are more sceptical (Pratt and Pyle 2000). With this uncertainty this species is only possibly extinct, but if it does persist the population size is likely to be very small (<50 mature individuals) and so this species warrants listing as Critically Endangered (Possibly Extinct) under criterion D.
H. hanapepe is only confirmed from historical records on the Hawaiian island of Kaua’i in mesic to wet ohia-koa forest (Pratt 2016b). Munro (1960) doubts that it has been since the late 1890s. However, there have been possible more recent sightings including a brief glimpse of 2 birds in 1960, with the most recent unconfirmed sighting being in 2007 (Pratt 2010); but it has been suggested that reports fail to exclude the possibility of the sighting being of Kaua’i Amakihi (P. Baker in litt. 1999, Pratt and Pyle 2000, Pratt 2016b). There have been intensive surveys on Kaua’i that have failed to find this species, and it has been considered extinct by some authors (Pratt and Pyle 2000, Reynolds and Snetsinger 2001, R. Camp in litt. 2003). However, considering there have been recent tentative possible reports (although unconfirmed) this species may still be extant. If it does still survive then the total population size is likely to be very small (<50 mature individuals). Therefore, it is proposed that this species be listed as Critically Endangered (Possibly Extinct).
Comments are invited on these proposed categories and further information would be welcomed.
BirdLife International 2016. Species factsheet: Hemignathus lucidus. Downloaded from http://www.birdlife.org on 01/10/2016.
Munro, G.C. (1960) Birds of Hawaii. Bridgeway Press Books, Austin.
Pratt, D. 2016a. Maui Nukupuu (Hemignathus affinis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/61447 on 1 October 2016).
Pratt, D. 2016b. Kauai Nukupuu (Hemignathus hanapepe). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/61446 on 1 October 2016).
Pratt, H.D. 2010. Family Drepanididae (Hawaiian Honeycreepers). In Handbook of the Birds of the World Volume 15: Weavers to New World Warblers (J. del Hoyo, A. Elliott and D.A. Christie eds). Lynx Edicions, Barcelona.
Pratt, T.K. and Pyle, R.L. 2000. Nukupu’u in the Twentieth Century: Endangered Species or Phantom Presence? Elepaio 60: 35–41.
Reynolds, M. H. and Snetsinger, T. J. 2001. The Hawai`i Rare Bird Search 1994-1996. Studies in Avian Biology 22: 133-143.
Tobias, J. A., Seddon, N., Spottiswoode, C. N., Pilgrim, J. D., Fishpool, L. D. C. and Collar, N. J. 2010. Quantitative criteria for species delimitation. Ibis 152: 724–746.