Is there even proof of ostriches breeding in the wild in Australia?
Pretty sure there have been sightings of young - at least near Barham.
My Dad wrote a blog entry back in 2009 reporting that someone on the Birding-Aus mailing list had sighted a pair of Ostriches with 9 chicks on Mt Arden Station near Port Augusta (quite a bit further north than Emeroo) - so it seems like there may be at least one group breeding in that area still (albeit 10 years ago).
The Port Augusta population has to be at least 40 years old - since it was there when I started school. My Dad tells me that one of the other teachers at the school he worked at was living at Emeroo station where they were kept (about 15km north east of Port Augusta). That would have been in the late 70's / early 80s. I'm not sure when they stopped farming there.
The original Ostrich farm there was started in the 1880s and there are photos from 1913 in the SA State Library: ostrich farm port augusta • Find • State Library of South Australia ... but I believe the farming was stopped at some point after that before being started again in the 1970s - which would be the population I recall seeing growing up.
Recent news article about Ostriches - The outback ostriches — Australia's loneliest birds ... they also assert that most of the sightings would be from escaped Ostriches from the farms rather than wild born.
Newspaper article from 1888 about the Ostrich farm near Port Augusta: THE PORT AUGUSTA OSTRICH FARM. - The South Australian Advertiser (Adelaide, SA : 1858 - 1889) - 13 Feb 1888
Interestingly, the area near Emeroo is now used for farming solar energy - with a huge solar farm being build there: Bungala Solar Power Project - Wikipedia