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.
Northern Brown Kiwi Apteryx mantelli is being split into A. mantelli and A. rowi, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, A. mantelli (BirdLife species factsheet) was listed as Endangered under criteria A2bce+3bce+4bce because, although mainland populations of this species were thought to be in extremely rapid decline (at least 80% over 26 years [estimate of three generations]), based on annual survey results and the known impacts of threats, the overall rate of population decline was thought to be very rapid (50-79% over 26 years) owing to the stability of island populations and intensive predator control in some mainland populations.
A. rowi is known only from Okarito Forest, on the west coast of South Island, New Zealand, where it is restricted to c.10,000 ha of coastal podocarp-hardwood forest between the Okarito River to the north and Waiho River to the south (Tennyson et al. 2003). The species’s pre-human range is not known. It is suggested that it be listed as Endangered under criterion D, on the basis that it has an extremely small population, probably including fewer than 250 mature individuals, as it has been estimated that there are 150-200 individuals (Tennyson et al. 2003) and more recently 300 individuals (Holzapfel et al. 2008), and the population is thought to be increasing (Miskelly et al. 2008, who, along with Hitchmough et al. 2007, list the taxon as Critical at the national level under modified criteria).
A. mantelli (as defined following the taxonomic change) exists in fragmented and isolated populations on North Island and adjacent islands, New Zealand. It favours dense, subtropical and temperate forests, but also occurs in shrublands, scrub, regenerating forest, exotic pine plantations and pasture (Marchant and Higgins 1990). It is suggested that this species be listed as Endangered on the same basis as the listing of the pre-split species, that is under criteria A2bce+3bce+4bce, because mainland populations of this species may be decreasing extremely rapidly, based on annual declines, predation and loss of habitat. However, owing to the stability of island populations, and intensive predator control in some mainland populations, the overall decline is likely to be slower, but still very rapid (50-79% over 26 years).
Comments on these suggested categories and further information would be welcomed.
Hitchmough, R., Bull, L. and Cromarty, P. (2007) New Zealand Threat Classification System lists 2005. Wellington, New Zealand: Science & Technical Publishing, Department of Conservation.
Holzapfel, S., Robertson, H. A., McLennan, J. A., Sporle, W., Hackwell, K. and Impey, M. (2008) Kiwi (Apteryx spp.) recovery plan: 2008–2018. Wellington, New Zealand: Department of Conservation.
Marchant, S. and Higgins, P. J. (1990) Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Melbourne, Australia: Oxford University Press.
Miskelly, C. M., Dowding, J. E., Elliott, G. P., Hitchmough, R. A., Powlesland, R. G., Robertson, H. A., Sagar, P. M., Scofield, R. P. and Taylor, G. E. (2008) Conservation status of New Zealand birds, 2008. Notornis 55(3): 117–135.
Tennyson, A. J. D., Palma, R. L., Robertson, H. A., Worthy, T. H. and Gill, B. J. (2003) A new species of kiwi (Aves, Apterygiformes) from Okarito, New Zealand. Records of the Auckland Museum 40: 55–64.
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.