Birds of South Australia's Journal

October 14, 2021

Identifying the Thornbills of South Australia



Australian Thornbills (Genus Acanthiza) are notoriously difficult to identify. Difficult in the field and more difficult from photos alone. The tips below are a good starting point toward learning to ID the Thornbill species present in SA. Visit the Thornbills of South Australia project to see all the observations in SA.


The Family Acanthizidae has 41 species across Australia with around 24 present in SA. The Genus Acanthiza includes 12 species across Australia with 9 of those occurring in SA.


Below are a few tips to help separate and identify these 9 species, with links through to the observations from SA so you can see what the distinguishing features look like in a variety of image qualities. The list is ordered based on the number of iNat observations. Those higher on the list are more frequently seen, likely due to their presence in more populated areas. Additionally those with the most distinct characteristics are more likely to be IDed to species level, so are higher on the list.


Acanthiza chrysorrhoa (Yellow-rumped Thornbill)
Birdlife Australia species page
eBird species page

Distinguishing Features: The bright yellow rump is sufficient alone to distinguish this species from others in SA. But this may not be visible if the Bird is facing the camera. In that case look for the black forehead with white spots, and dark eye stripe. In the right light, the grey/brown of the eye is visible. Most easily confused with Acanthiza reguloides (Buff-rumped Thornbill) which has a buff forehead and clear white eye.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza lineata (Striated Thornbill)
Birdlife Australia species page
eBird species page

Distinguishing Features: Look for the chestnut crown with white streaks. Heavy streaking on the chin, throat and chest. In the right light, the grey/brown of the eye is visible. Most easily confused with Acanthiza pusilla (Brown Thornbill), which has a reddish-brown forehead scalloped with paler markings and red eye.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza pusilla (Brown Thornbill)
Birdlife Australia species page
eBird species page

Distinguishing Features: Reddish-brown forehead scalloped with paler markings. Rufous brown rump. Narrow black band on tail feathers. In the right light, the red brown of the eye is visible. Most easily confused with Acanthiza apicalis (Inland Thornbill), which has black and white scalloping on the forehead a wider black tail feather band, and Acanthiza lineata (Striated Thornbill), which has a chestnut crown with white streaks.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza uropygialis (Chestnut-rumped Thornbill)
eBird species page

Distinguishing Features: Strong chestnut rump. Grey cream underparts without streaking. Buff forehead. In the right light, the clear white of the eye is visible. Most easily confused with Acanthiza apicalis (Inland Thornbill), which has streaking on the throat and chest.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza nana (Yellow Thornbill)
Birdlife Australia species page
eBird species page

Distinguishing Features: The most yellow of the local Thornbills, with pale yellow underparts and white streaking restricted to the cheeks and ears. In the right light, the dark brown of the eye is visible. Most easily confused with Acanthiza lineata (Striated Thornbill), which has a chestnut crown with white streak, and heavily streaked chin, throat and chest.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza reguloides (Buff-rumped Thornbill)
Birdlife Australia species page
eBird species page

Distinguishing Features: Buff-coloured rump and black tail. Buff-coloured forehead with cream-coloured scalloping. Off-white chin and chest without streaking. In the right light, the clear white of the eye is visible. Most easily confused with Acanthiza chrysorrhoa (Yellow-rumped Thornbill), which has a bright yellow rump and black forehead with white spots.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza apicalis (Inland Thornbill)
eBird species page

Distinguishing Features: Black and white scalloping on the forehead, streaking on the throat and chest. Wide black band on the tail feathers. In the right light, the red of the eye is visible.
Most easily confused with Acanthiza pusilla (Brown Thornbill), which has a reddish-brown forehead scalloped with paler markings and a narrow black band on the tail feathers.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza iredalei (Slender-billed Thornbill)
eBird species page

Distinguishing Features: Pale buff rump with contrasting darker tail. Faint speckling on the chest. Pale speckled forehead and face. In the right light, the clear white of the eye is visible.

ID practice: Review the observations from SA and look for these features in the photos.


Acanthiza robustirostris (Slaty-backed Thornbill)
eBird species page

Distinguishing Features: Dark streaking on the forehead. Only present in far North-West SA. In the right light, the red of the eye is visible. Most easily confused with Acanthiza apicalis (Inland Thornbill), which has streaking on the chest and black and white scalloping on the forehead.

ID practice: No iNat observations from SA. Review the observations from around Australia and look for these features in the photos.


Can you use these tips to ID the four species in the image at the beginning of this post?


Images used in this post © Geoffrey Cox, some rights reserved (CC-BY)

Posted on October 14, 2021 08:42 by cobaltducks cobaltducks | 0 comments | Leave a comment

May 08, 2021

So South Australian Golden Whistlers are really Western Whistlers?

Australian Golden whistlers have a complicated taxonomic history with identifiable forms across the continent being at various times considered separate species, subspecies of a single widespread species or, most recently, more than one species, though still incorporating several subspecies. Different authorities do not always agree on the validity of name combinations which has added to the confusion.

The South Australian Golden Whistler, a familiar sight in habitats ranging from stringybark forest to mallee woodlands in SA (and western Victoria), was originally described as a full species, Pachycephala fuliginosa, but most recently has generally been considered to be a form of the Eastern Golden Whistler (Pachycephala pectoralis) by most authorities, including the one that iNaturalist derives its bird taxonomy from. Thus, the full name of the SA form in iNat is Pachycephala pectoralis subspecies fuligens.

A recent study (Joseph et al. 2020), however, has found that South Australian Golden Whistlers are morphologically and genetically much closer to birds from SW Western Australia than to golden whistlers from eastern Australia and are essentially indistinguishable from western birds. The WA population has, for some time, been considered to be a separate species, the Western Whistler, Pachycephala occidentalis. The researchers’ conclusion is that SA birds should be considered a subspecies of the Western Whistler rather than of the Golden Whistler. So, if the Western Whistler and the South Australian Golden Whistler are one and the same species, how will this affect its scientific name? The principle of priority observed in zoological nomenclature means that the first name validly applied to a taxon is the one that is retained. In this instance the epithet ‘fuliginosa’ was applied to this species before the name ‘occidentalis’, so it takes priority – the Western Whistler and the SA Golden Whistler will become Pachycephala fuliginosa with SA birds being P. fuliginosa subsp. fuliginosa (referred to as the nominate subspecies) and WA birds being known as P. fuliginosa subsp. occidentalis (the former species epithet being retained as the subspecies name). There are no set principles for deciding common names but ‘Western Whistler’ (or ‘Western Golden Whistler’) is still appropriate for South Australian birds when referring to the species as a whole, and perhaps ‘South Australian Western Whistler’ could be applied to the SA subspecies.

That all said, don’t rush off to reidentify all the SA and western Victorian iNat observations as Western Whistler just yet. This taxonomic change will need to be adopted by the bird names authority that iNat follows (Clements Checklist) before the iNat taxonomy will change. When it is updated the changes should flow through automatically based on geography. Unfortunately, the Clements Checklist, being US based (Cornell Ornithology Lab), can be very slow to update Australian bird names so it might be quite a while before we actually see the change here in iNat. In the meantime, if you want to be on top of your game, taking the IDs of SA observations right through to subspecies level can help. When the swaps are eventually made in iNat, Pachycephala pectoralis subsp. fuligens IDs will be directly swapped for the new Pachycephala fuligens (Western Whistler) taxon record.

Click on this link if you’d like to read the abstract to the Joseph et al. (2020) paper summarising the study - https://www.tandfonline.com/doi/abs/10.1080/01584197.2020.1854047?journalCode=temu20

Posted on May 08, 2021 12:25 by rfoster rfoster | 0 comments | Leave a comment

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