Grasswrens: hidden but not forgotten

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Museum skins showing similarity and diversity among populations of the two grasswren species. From left: Amytornis textilis myall from north-eastern Eyre Peninsula, South Australia; A. modestus modestus from central Australia (extinct); A. modestus indulkanna from west of Lake Eyre; A. modestus raglessi from near the North Flinders Ranges; and A. modestus curnamona from the southern Lake Frome Basin.

Fairywrens (Malurus spp.) are a familiar favourite of many people, but bird watchers are increasingly fascinated by a special group within the same family  grasswrens (Amytornis species).

Honorary Research Associate at the Museum, Andrew Black has spent about seven years working on a project examining the Amytornis textilis-modestus group.

Grasswrens are found only in continental Australia, mostly in arid zones, but there are also three monsoon tropical species. Field identification is very difficult as the species are morphologically very similar and are skilled at hiding within their habitat. However, there are subtle variations that indicate very different and intriguing evolutionary histories between groups.

Early grasswren classifications contained many errors with observers misidentifying different groups. This history of misidentification is one reason why grasswren taxonomy is still under development  placing it amongst the latest to be developed within Australian birds. John Gould’s iconic publication ‘Birds of Australia’ only named three species of grasswrens, two of which were incorrect.

Working with two professional field ornithologists Lynn Pedler and Graham Carpenter, and using museum specimens, Andrew has identified two species (Amytornis textilis and A. modestus) and several sub-species within each species. Andrew also works closely with Dr Jeremy Austin at the University of Adelaide who has conducted genetic analysis on specimens from the Museum’s collection. Andrew also collaborated closely with Museums in Melbourne, Sydney, Canberra and Perth to examine grasswren specimens collected from all over Australia. Specimens from the South Australian Museum’s frozen tissue database were used for genetic analysis. Two PhD students at Flinders University are building on the progress made by Andrew and his colleagues and are investigating grasswren life history and population genetics. 

The grasswren classification project coincides with research examining the history of ornithology at the Museum. Historical specimens of Australian grasswrens in American and European museums contain most of the early extinct subspecies from this group of grasswrens. There is one extinct subspecies for which the Museum does not have DNA. The next step is to see if genetic material can be obtained from these specimens housed overseas as well as other grasswren species to extend the current phylogeny.