The Kiwi Family

Then, in the 1980s, genetic research allowed kiwi to be studied at the very deepest level - that of their DNA (deoxyribonucleic acid). DNA contains the genetic instructions used in the development and functioning of all known living organisms. By comparing kiwi DNA, geneticists have been able to infer the species’ evolutionary history.
 
The genetic research has led to brown kiwi being split into three distinct species –  brown kiwi, rowi and tokoeka. Today, five kiwi species are formally recognised, although further genetic research may identify more species and/or subspecies, especially within tokoeka.

The five species

 The five formally described kiwi species are:

• brown kiwi (Apteryx mantelli) in the North Island
• little spotted kiwi (A. owenii) on several offshore islands and at Karori Sanctuary in Wellington
• great spotted kiwi/roroa (A. haastii) in the northern South Island
• rowi (A. rowi) at Okarito, on the West Coast of the South Island
• tokoeka (A. australis) in Fiordland, the Haast Range and on Stewart and Kapiti Islands.

Different forms

It is, however, not that simple because kiwi researchers often use the general term taxa (singular: taxon) to refer to the 11 different kiwi, which are either species or distinct geographical varieties within species.

• Within brown kiwi, four geographically and genetically distinct forms have been distinguished: Northland, Coromandel, western and eastern. 
• Tokoeka also have four distinct geographical forms: Haast, northern Fiordland, southern Fiordland, and Stewart Island.

The other species show no clear geographical genetic variation, though a distinct North Island form of little spotted kiwi existed before it went extinct in the late 1800s.