Are you really seeing Grey Ducks?
A Pair of Grey Duck in Australia showing features of pure birds. A well marked face. Distinctive pale edged feathers and dark bills.
Using the key below if your duck scores more than 7 it is almost certainly a hybrid, I’m afraid. Why not put the hybrid index score in the comments column for your observation?
|
Characteristic |
Species |
Assessment |
Value (The index gives a score of 0 for the purest Grey Duck and 35 for the purest Mallard) |
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Face striping |
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Grey 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 |
|
|
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|
Speculum border - anterior |
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Grey Duck |
No white bar |
0-1 |
|
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Hybrid |
Thin white bar (2 mm) |
2-3 |
|
|
Mallard |
Broad white bar (5 mm) |
4-5 |
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|
Speculum border - posterior |
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|
Grey Duck |
Faint white line |
0-1 |
|
|
Hybrid |
Thin white bar (2 mm) |
2-3 |
|
|
Mallard |
Broad white bar (5 mm) |
4-5 |
|
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Bill |
|
|
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Grey Duck |
Slate gray |
0-1 |
|
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Hybrid |
Gray-yellow |
2-3 |
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|
Mallard |
Yellow-orange |
4-5 |
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Nape |
|
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Grey Duck |
Cream |
0-1 |
|
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Hybrid |
Creamy brown |
2-3 |
|
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Mallard |
Dark brown in female or eclipse male, varying from a dark green to a purple-green in the breeding plumage male |
4-5 |
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Tail |
|
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Grey Duck |
Slate gray |
0-1 |
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Hybrid |
Gray-brown |
2-3 |
|
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Mallard |
Creamy brown in female or eclipse male, varying from a dark green to a purple-green in the breeding male |
4-5 |
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Leg |
|
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|
Grey Duck |
Gray-brown |
0-1 |
|
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Hybrid |
Gray-yellow |
2-3 |
|
|
Mallard |
Yellow-orange |
4-5 |
