Scrubwrens

Some interesting discussion, but Graeme and others I think it is rather premature to be drawing the boundary delimiting Spotted Scrubwren from White-browed. In particular, note that Kangaroo Island’s ashbyi aligned with eastern birds on mitochondrial DNA in the recent Norman et al paper, though the authors did recommend leaving ashbyi in maculatus (on morphological evidence) pending further study of this glaring problem. Also note that on measures (bill, wing, tarsus) ashbyi aligns with eastern birds (rosinae) not mellori (see DAB), and that island forms often tend towards melanism.

There is plenty of morphological evidence of intergrades or historical introgression between the various subspecies in SA, as discussed at length in DAB and HANZAB. Clearly nailing the species boundary (+/- a hybrid zone) will require a multilocus genetic study with much better sampling across the whole area. Breast spotting, eye colour, etc just aint going to cut it. HANZAB discusses iris colour and suggests that though there is a broad geographic pattern, it is also variable within subspecies; also that south-western maculatus of wet forests do indeed have a yellower eye, suggesting it is habitat driven thus less useful for species circumscription.

Cheers
Martin