Mynas and the pox

 In a discussion of the spread of COVID I, possibly unwisely, drew an analogy between the disease spreading down the Hume Highway and the spread of Common Mynas.  That led to an interesting comment on my Facebook page which requires a little more work to show the situation more fully.

Interested readers might like to peruse the website of the Canberra Indian Myna Action Group (CIMAG).  The vernacular name of the species is now officially Common Myna but the Action Group was formed using the old name (and it has a snappier acronym).

I joined COG in 1983, shortly after arriving in Canberra.  Either in that year or the next I saw m first Indian Myna (as they were then known) in our yard at Scullin.  Discussing this with the then manager of the Canberra Ornithologists Group (COG) Garden Birds Survey (GBS) he said that the species was mainly confined to an area around Green Square in Kingston with a secondary flock around the Scullin Medical Centre (about 300m from our house.

The population then exploded as shown in the first chart below.

The story behind the species appearance in Canberra is that in the 1970s a Canberra residents had been in hospital in Sydney having serious surgery.  As he awoke from the operation the first sound he heard was the squawks of Mynas on the window ledge outside his ward.  To him this was like rebirth and a source of joy.  One assumes that when listening to music 'melody' is not high on his list of criteria!  However he felt he should share his joy with people in Canberra and somehow shipped a dozen of the birds up to the Inner South.  The rest is history (I have no idea how they got to the satellite site in Scullin).

This chart shows the situation up to 2000.

At some point in the late 1990s Dr Chris Tidemann from the Fenner School within ANU started researching the distribution and abundance of Mynas across Canberra.  He used statistically transect surveys to measure abundance and compared the results with A-values (effectively, average numbers of Mynas per survey week) and found the GBS results to compare closely with his data  This validates the GBS as a data source at that time.  I have stressed the time reference as the survey panel for the GBS is self selecting and may no longer reflect the overall situation (for example is has relative low penetration into the new, McMansion-enhanced (😆😆) suburbs in South Tuggeranong, Gungahlin and Molonglo).

In 2006 growing disquiet in the community about the rats-with-wings led to the formation of CIMAG.  At that stage Mynas were the third most common bird species in Canberra, as measured by the GBS.

The impact of the CIMAG "trap and euthanase" programme the abundance of Mynas dropped dramatically.  However it has not led to the species disappearing as shown in this longer time series from the GBS (I don't have data from 2012 to 2016 on hand but from memory they are in the range 1.50 to 2.50).

COG also has more general data on its website (unfortunately not updated since 2017) but consistent with the above.  It includes a distribution map:

This shows some expansion of the species beyond the urban area and particularly abundance in the Gungahlin area.

In summary I hope the ACT has more luck in controlling COVID!