New species of kiwi

Kiwis Apteryx are well known as the national symbol of New Zealand. Due to their nocturnal habits and now mostly restricted ranges, they have been hard to study. That detailed studies could reveal some taxonomic surprises is therefore not totally unexpected. Up to now, two groups including three species were recognized: the brown kiwis (one polytypic species, Brown Kiwi A australis) and the spotted kiwis (two monotypic species: Little Spotted Kiwi A oweni and Great Spotted Kiwi A haasti). Recent studies of the brown kiwis have confirmed that three different 'varieties' within this group represent, in fact, cryptic species, one of which is described as a new species (Tennyson, A J D, Palma, R L, Robertson, H A, Worthy, T H & Gill, B J 2003. A new species of kiwi (Aves, Apterygiformes) from Okarito, New Zealand. Rec Aukland Mus 40: 55-64). The new species has been named Rowi (or Okarito Brown Kiwi) A rowi. The other two species are North Island Brown Kiwi A mantelli and Tokoeka A australis. Rowi occurs only in Okarito forest on the West Coast of South Island; its total population was estimated at 200 birds in 2002 (in an area of 10 000 ha) and it is labelled as 'nationally critical'. In 1998, the population was estimated at only 140 birds. Tokoeka occurs in south-western South Island: Haast Tokoeka A a australis in the Haast area and Southern Tokoeka A a lawryi in Fiordland and on Stewart Island. North Island Brown Kiwi occurs on North Island.
The new species differs only slightly from the other brown kiwis. Differences can be found in plumage colour and colouration of bare parts, which are all paler than in other brown kiwis with the head, neck and belly feathers noticeably grey (often with some white on the head), the softness of the feathers (softer when stroked backwards than in Tokoeka), the shorter bill and the barred outer wing feathers (not present in the other brown kiwis). Apart from the holotype, only six specimens (paratypes) of the new species are known. The English name and scientific name is derived from one of the vernacular names of the new species. The studies revealed that Rowi is more closely related to North Island Brown Kiwi than to the geographically closer Tokoeka.
The existence of more than one species of brown kiwi had already been deduced from molecular studies in 2001 and was published two years later (Burbidge, M L, Colbourne, R M, Robertson, H A & Baker, A J 2003. Molecular and other biological evidence supports the recognition of at least three species of brown kiwi. Conserv Genet 4: 167-177). However, the name 'Apteryx rowii' used in this publication does not comply in every aspect with the rules set by the International Commission on Zoological Nomenclature and the same applies to earlier descriptions of this taxon, all leading to invalid scientific names (nomina nuda). A nomen nudum ('naked name') implies that the given name has no official status (is invalid) and should not be used to refer to the taxon involved. Considering the urgent need for a properly established scientific name for the new species, Tennyson et al (2003) decided that it was best to quickly name and describe the new species in a separate publication.
Tokoeka is a polytypic species with at least three different 'lineages', now grouped into two subspecies. Further studies may reveal that more subspecies should be recognized or that subspecies should also be awarded species status. More information on the status, population and distribution of all five kiwi species, including colour photographs of each species, can be found at the kiwi recovery website (www.savethekiwi.org.nz).
ENNO B EBELS