Friday, 22 August 2014

A couple more mysteries

The first of arose at a dam on the outskirts of Bungendore yesterday where I observed this duck.
It looked to me pretty much like a true Mallard rather than the more often observed Mallard x Pacific Black Duck hybrids.  So I sought opinions on its identification from members of COG.  A couple of people agreed with me but some others didn't.  The most detail explanation of why it was a 'domestic form' rather than a 'wild form' included the following:
 ....  it looks almost like a pure Mallard but it is not in my view (well, I'm adamant that it is not!). Geoffrey is correct that the 'stern' should be black, not grey. Also, the flanks are too pale - they look pretty white in the photo - the back (wings) also look a bit pale, and I reckon the head should look more green. There is no sign of the speculum which should be blue, bordered white, and would be prominent on a genuine Mallard. 
As the comments came from a very experienced birder I have reported it to eBird as a Mallard - domestic form.  A number of respondents to my post suggested the bird should be removed from the gene pool rather swiftly.  (From my own perspective if it hybridises so easily with 'our' Pacific Black Ducks I question their distinction into separate species!)  The proponents of duck soup know where the bird is (it has been sighted there by others over the past month) and are welcome to liaise with the landholder to arrange same!

So that is another mystery solved.

The second mystery in this batch is a whodunnit.  A small (about 2cm trunk diameter) Acacia dealbata near our house was given a thorough chewing overnight.
A first point is that we do not have Castor canadensis on our property.

It looks to me as though 'something' was tunneling up the inside of the trunk and that may have attracted the attention of a cockatoo.  The wanton way the chips have been checked also leads my thoughts in that direction.  While we have had a few Yellow-tailed Black-Cockatoos around recently they have always been active in destroying pine cones.  I have not noticed any Sulphur-crested Cockatoos around.

When trees get damaged our go-to suspect is a Swamp Wallaby, but they are usually interested in foliage rather than wood or grubs.  Wombats are certainly active in the area but I am not aware of them eating trees (or grubs).

Suggestions welcome.

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