RE: Mallard 'threat' in Victoria (Aust.)

Are Mallards a threat to native ducks in Australia?  It would be interesting to have a good look at the arguments for the case in the unsuccessful submission mentioned by Martin O'Brien in an earlier posting.  

Some caution needs to be exercised when comparing the situation in New Zealand (where Mallards ARE a problem) to that in Australia.  I don't doubt that there is some interchange of genes between Mallards and Black Duck in Australia but that doesn't automatically mean that the Black Duck population is going to be swamped by Mallard genes.

Consider for a moment where the vast majority of Australia's ducks are produced.  Most ducks breed in the arid and semi-arid interior of this country on semi-permanent and ephemeral wetlands in what can only be described as a 'boom' and 'bust' cycle.  Yes, I know everyone has seen Black Duck breeding on the coast but the majority do originate inland - and a hell of a lot further inland than many would appreciate.  An exception to this trend (among the common "game" ducks) would be the Chestnut Teal which really is a more "coastal" species.

Now consider where you find Mallards.  In Australia they tend to be more common in semi-domestic situations - urban lakes are a common habitat.  Yes, again, I know people have seen them in far flung wetlands but most are found in well settled areas. This is very contrary to the New Zealand situation where they are widespread and abundant.  

It therefore seems that the chance for Mallards to interbreed with Black Duck is limited to these more urban areas - and this is precisely where we do see hybrid ducks.  The research that I've done suggests that there appears to be little hybridisation with Chestnut Teal.  There is also the suggestion that many so-called hybrids between Black Duck and Mallard are, in fact, misidentification of various 'breeds' of domestic duck derived from Mallards.

Cheers

David Geering




This message is intended for the addressee named and may contain
confidential information. 

If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message may be those of the individual sender, and are not necessarily the views of the NSW National Parks and Wildlife Service.