This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for non-passerines
Lynx Edicions and BirdLife International will soon publish 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 1 of the checklist (for non-passerines) will begin to be incorporated into the 2014 Red List update, with the remainder, and those for passerines (which will appear in volume 2 of the checklist), 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.
New Zealand Snipe Coenocorypha aucklandica is being split into C. aucklandica, C. iredalei and C. huegeli, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, C. aucklandica (BirdLife species factsheet) was listed as Near Threatened under criteria B1ab(iii); D2, on the basis that it occurs at a small number of locations. This species has been extirpated from most of its historic range by introduced mammalian predators, to which it is highly susceptible. Declines have ceased as it is now confined to a few predator-free Sub-Antarctic islands where it is relatively secure within a very small range.
C. iredalei is thought to be most appropriately listed as Extinct, on the basis that it is very unlikely to have been extant since 1964 (Szabo et al. 2012). Only two individuals were found after the accidental introduction of black rats Rattus rattus onto Stewart Island in 1964. Both of these birds were taken into captivity but died soon after (Tennyson and Martinson 2006).
C. huegeli is endemic to Snares Island, and is thought to qualify as Vulnerable under criterion D2, on the basis that it occurs at one location and is susceptible to the introduction of non-native predators, which could result in it qualifying as Critically Endangered or Extinct within one or two generations.
C. aucklandica is found on the Auckland Islands (excluding the main island), the Antipodes Islands (form meinertzhagenae) and Jacquemart Island in the Campbell Island group (form perseverance), whilst the population on Little Barrier Island (form barrierensis) has been driven extinct by invasive species (Tennyson and Martinson 2006). It is suggested that it qualifies as Near Threatened under criteria B1ab(iii); D2, on the basis that it occupies a very small range (with an Extent of Occurrence estimated at c.680km2), at only a few locations, but is not in decline and, although plausible threats such as the introduction of non-native species to parts of its range could drive it to qualify as Vulnerable or Endangered within one or two generations, given its distribution it is unlikely to qualify as Critically Endangered or Extinct within one or two generations because of any known and plausible threats.
Comments are invited on these suggested categories and further information would be welcomed.
Szabo J. K., Khwaja, N., Garnett S. T., Butchart S. H. M. (2012) Global Patterns and Drivers of Avian Extinctions at the Species and Subspecies Level. PLoS ONE 7(10): e47080. doi:10.1371/journal.pone.0047080
Tennyson, A. J. D. and Martinson, P. (2006) Extinct Birds of New Zealand. Te Papa Press, Wellington.
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.