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.


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?


4-Day BioBlitz History

With the Great Southern BioBlitz 2021 approaching, I thought I’d review my City Nature Challenge and Great Southern BioBlitz history, and see if I can break some personal records during the GSB2021.

I’ve previously taken part in the City Nature Challenge 2020 with 1172 observations of 372 species, the Great Southern BioBlitz 2020 with 1440 observations of 461 species, and the City Nature Challenge 2021 with 1403 observations of 426 species.

City Nature Challenge 2020
My first attempt at a 4-day BioBlitz was the CNC2020. Taking place in our Autumn, this wasn’t an ideal time of year to discover as many species as possible. The weather can put a damper on most activity and the short daylight hours can be limiting. Many seasonal plant species aren’t present, Insects are hidden away in egg or larval stages, and identifying plants without flowers can present difficulties. Nevertheless, over the four days I visited 17 locations recording 1172 observations covering 373 species (using the ‘leaf count’ method), with 325 of those identified all the way to species.

Given the season and ease of observation, Plants featured heavily with the top 24 most recorded species being Plants. Most recorded was the Myrtle Wattle (Acacia myrtifolia) with 24 records across 8 different locations. The most recorded Bird was the Superb Fairywren (Malurus cyaneus), with 7 records across 7 different locations. The first Insect, the Meadow Argus (Junonia villida) appeared in 25th place with 6 records.

Observations from my property over the 4 days totalled 155 records covering 78 species. Many of these were Lepidoptera attracted to a UV light, however the species total also included 6 Flies, 6 Beetles, 5 Arachnids, 5 Plants (naturally occurring), 3 Molluscs and 3 Ants.

CNC2020 Highlights:

Great Southern BioBlitz 2020
This is a BioBlitz much more suitable for tracking down those Spring flowers and Insects. The first Great Southern BioBlitz offered warm days with longer daylight hours. But the weather doesn’t always play nice as I found myself in the middle of Ferries-McDonald CP fending off a hailstorm.

Over the four days I visited 17 locations recording 1440 observations covering 461 species (using the ‘leaf count’ method), with 403 of those identified all the way to species. That’s +268 observations and +89 species beyond the CNC2020 totals.

The higher species count came from both records of seasonal plants and the inclusion of two beach locations in the mix which brought in additional marine species. While Plants feature heavily in the most observed list, 4 of the top 5 observed species were seasonal Orchids, with the Waxlip Orchid (Glossodia major) taking out the top spot having 23 observations across 3 different locations. The most observed Bird was the Australian Pelican (Pelecanus conspicillatus) coming in 9th place with 11 records across 4 different locations. The first Insect was again a Butterfly, with the Australian Painted Lady (Vanessa kershawi) coming in 52nd place with 5 records across 2 different locations.

Observations from my property over the 4 days totalled only 61 records covering 33 species. The lower numbers than in the CNC2020 were due to poor weather limiting the use of the UV light and time to search in the yard.

GSB2020 Highlights:


City Nature Challenge 2021
My second run at the City Nature Challenge followed much the same pattern as the first, with Plants featuring heavily, followed by Birds, and few Invertebrates.

Over the four days I visited 14 locations recording 1403 observations covering 426 species (using the ‘leaf count’ method), with 364 of those identified all the way to species. This was less than during the Spring GSB2020, as expected, but compared to the previous Autumn CNC2020 it was +231 observations and +54 species.

I had expected that across both years the species seen would have been fairly similar. The locations visited were different, but generally within the same region. However comparing both species lists (using the iNat compare tool) showed that of the 426 species seen in the CNC2021, 225 of them were NOT seen in the CNC2020. And of the 372 species seen in the CNC2020, 177 were NOT seen in the CNC2021. This strongly suggests that the key to recording as many species as possible during the BioBlitz is to visit as many, and varied, locations as possible. As opposed to longer visits to fewer locations.

The most observed species was the Golden Wattle (Acacia pycnantha), with 31 records across 5 different locations. Some species featured heavily this year due to choice of location, such as the Mount Lofty Ground-Berry (Acrotriche fasciculiflora) which placed 6th with 16 observations across only 2 locations in the Adelaide Hills.

Observations from my property over the 4 days totalled only 191 records covering 79 species. Lepidoptera featured heavily (143 observations) thanks to some warm weather. Interestingly, even though these observations were recorded at the same location and the same time of year, there was limited crossover. In the CNC2021 there were 50 species not recorded in CNC2020, and in the CNC2020 there were 52 species not recorded in the CNC2021. This suggests with a little effort the number of species recorded on my property over the 4 days could be doubled.

CNC2021 Highlights:


Great Southern BioBlitz 2021
This all brings us to the Great Southern BioBlitz 2021. This year I’ll be looking at visiting new locations and recording new species. Having learnt a few lessons from the previous BioBlitz events, I’ll be aiming to:

  • Add 50 new species to my life list.
  • Record at least 1,500 observations.
  • Record at least 500 species.


It’ll take a bit of effort to achieve all three. I’ll be visiting some semi-arid locations to track down some new species, however such areas tend to have lower species diversity, so I may be hard pressed to reach 500 species for the 4 days. It’ll also very much depend on the weather.


Good luck to anyone participating in this years Great Southern BioBlitz. Whether you’re heading out on all 4 days or just spending some time discovering the species in your own backyard, all will contribute important biodiversity records to the Atlas of Living Australia.