Greetings, the material below from the eBird Australia Facebook page may be of interest.
We have potentially three mallard taxa in the ACT: Mallard aka Northern Mallard, Mallard (domestic form) and Mallard X Pacific Black Duck (hybrids).
Prominent local authorities, including Dick Schodde and the author of the ducks section of the ABR, advise that there have been no confirmed records of pure Mallard/Northern Mallard in the ACT. I note that some ACT and NSW records of Mallard in eBird are
confirmed even though they do not provide field notes or photographs enabling the domestic form and hybrids to be excluded.
Queensland is currently reviewing a large number of bird species, Mallard is one of these. All individuals who have listed option 1 below have been asked to review their sighting. Individuals have been asked to provide notes on why they believe the bird
is pure form and not domesticated or if in fact domesticated to change their sighting to option 2. The review is our attempt to make the data provided by eBird in Queensland more accurate. A goal I believe all bird watchers strive to provide.
Interestingly, of all the requests made so far and replied to by bird watchers 90% have confirmed that in fact the bird in question was domesticated and that they did not realise that they had the three options to choose from or that they did not understand
the difference between the options.
Yes, we can select three options in Australia for Mallards:
Option 1:“Anas platyrhynchos - Mallard”;
Option 2: “Anas platyrhynchos (Domestic type) - Mallard (Domestic type)” and;
Option 3: The hybrid between Mallard and Pacific Black Duck – “Anas platyrhynchos x superciliosa - Mallard x Pacific Black Duck (hybrid)”.
If you select the first option, then it must show normal wild-type mallard size and wild-type phenotype. If so then use the standard “Anas platyrhynchos (Mallard)” designation. You will however need to provide a field notes/explanation and/or photo as
to why you believe this to be a wild-type bird and not a domesticated bird.
If you are unsure or have no notes for explanation then always use the second option - Anas platyrhynchos (Domestic type).
If you can identify that it is a hybrid between the Pacific Black Duck and the Mallard then use the third option - Anas platyrhynchos x superciliosa .
New Zealand eBird odes provide its members with a useful little key with ducks you suspect may be Pacific Black Ducks (Grey Ducks over there) to see if they really are pure. I have modified the table below replacing Grey Duck with Pacific Black Duck so
that bird watchers may use for this purpose in Australia.
Using the key below if your duck scores more than seven (7) it is almost certainly a hybrid Pacific Black Duck. You could put the hybrid index score in the comments column for your observation notes.
You can also use this key to look at the opposite whether the Mallard you are viewing is a hybrid or domesticated individual.
The index gives a score of 0 for the purest Pacific Black Duck and 35 for the purest Mallard.
If you select the first option, then it must show normal wild-type mallard size and wildtype phenotype. If so then use the standard “Anas platyrhynchos (Mallard)” designation. You will however need to provide a field notes/explanation and/or photo as to
why you believe this to be a wildtype bird and not a domesticated bird.
[Facial stripes]
Pacific Black Duck: Two clear black stripes on a cream background - 0-1
Hybrid: Obscured face stripes - 2-3
Mallard: No face stripe to a thin black eye stripe in the female - 4-5
Speculum border – anterior
Pacific Black Duck No white bar 0-1
Hybrid Thin white bar (2 mm) 2-3
Mallard Broad white bar (5 mm) 4-5
Speculum border – posterior
Pacific Black Duck Faint white line 0-1
Hybrid Thin white bar (2 mm) 2-3
Mallard Broad white bar (5 mm) 4-5
Bill
Pacific Black Duck Slate grey 0-1
Hybrid Grey-yellow 2-3
Mallard Yellow-orange 4-5
Nape
Pacific Black Duck Cream 0-1
Hybrid Creamy brown 2-3
Mallard Dark brown in female or eclipse male, varying from a dark green to a purple-green in the breeding plumage male 4-5
Tail
Pacific Black Duck Slate Grey 0-1
Hybrid Grey-brown 2-3
Mallard Creamy brown in female or eclipse male, varying from a dark green to a purple-green in the breeding male 4-5
Leg
Pacific Black Duck Grey-brown 0-1
Hybrid Grey-yellow 2-3
Mallard Yellow-orange 4-5
