The cline and fall of Western Fieldwren

The Western Fieldwren (Calamanthus [campestris] montanellus) has long had an on-again, off-again place on the Australian list. Even as the 1926 official RAOU Checklist [1] listed four Fieldwrens - Striated (fuliginosus), Rufous (campestris), Rusty (isabellinus/rubiginosus), and ‘Rock Fieldwren’ (montanellus) – the contemporary list of Mathews [2] listed only Striated and Rufous as species. A parallel situation exists today, with the international taxonomy of the IOC [3] recognizing montanellus as the full species Western Fieldwren, while Clements and the ‘official’ checklist of Christidis & Boles [4] lump it with Rufous. But it’s easy to forget that back then – until 1983 in fact - the ‘lumpers’ routinely aligned montanellus with Striated Fieldwren, on the basis of their shared olive and yellow (and lack of rufous) colouration. 

Given that interest is now stirring over how the ‘official’ Australian list will be maintained in the future, it’s worth a look back over the long-simmering arguments around the species status of the Western Fieldwren. 



Western Fieldwren Calamanthus [campestris] montanellus from the Stirling Ranges. Note the olive toned and heavily-streaked back; creamy-buffy underparts; russet on head confined to forehead; limited rufous in rump and tailbase; brown (not chestnut) lores; dull tail tips. This individual has a little more rufous than a ‘classic’ montanellus, notably in the cap and fringing on the wings.
[Image © Kay Parkin (http://kayparkinbirding.blogspot.com.au/2012/09/cheynes-beach-south-west-wa.html),
used with permission]