Systematic affinities of two enigmatic New Zealand passerines of high conservation priority, the hihi or stitchbird Notiomystis cincta and the kokako Callaeas cinerea.

Traditional systematic relations within the Passeriformes, perching birds, have recently been re-shuZed in a major review of the “largest avian radiation” (Barker et al., 2004). This includes now recognising Wve basal oscine passerine lineages, rather than the traditional view of two major groups, the Passerida and Corvida (Sibley and Ahlquist, 1990). The avian fauna of New Zealand provide key examples in this more complex view. Importantly, this includes the New Zealand wren family (Acanthisittidae), now regarded as a sister taxon to all other passerines (Barker et al., 2002; Ericson et al., 2002). New Zealand’s early split from Gondwana (82– 85 Myr ago) may explain the large evolutionary split of the wrens and other speciation events within the endemic avifauna of this country, and these features provide key support for a Gondwanan origin to early passerine diversiWcation (Barker et al., 2002, 2004; Ericson et al., 2002, 2003). Here, we focus on two enigmatic passerine species of New Zealand, not included in previous systematic studies based on DNA sequence data, but whose relationships are thought to lie within deep splits of the recently re-shuZed phylogeny. First, the hihi is currently classiWed as the sole representative of an endemic genus, Notiomystis, within the honeyeater family (Meliphagidae, Higgins et al., 2001). According to Sibley and Ahlquist’s (1990), DNA–DNA hybridisation distances the honeyeaters rest within the Corvida. Analyses of DNA sequence data, however, have