Grey ducks versus Mallards

What's in the Bag?

While every hunter can identify the greenheads, separating the grey ducks from the hen mallards can be a bit trickier. In most areas the majority of ducks shot display a combination of appearances. This is most likely due to the high level of hybridisation (interbreeding) between the two species. In the field, Fish & Game staff differentiate them according to which species a duck displays the strongest characteristics of. Apart from overall appearance, where greys are slightly smaller and have a darker plumage, there are several other main characteristics that we look at:

Grey Duck		Mallard Hen
Grey ducks have a pale head with a conspicuous dark facial stripe and grey bill.	Vs	Mallard hens have a more mottled face and an orange bill with a black saddle.
Grey ducks have olive legs and feet.	Vs	Mallards have orange legs and feet.
Grey ducks have a green speculum with black borders and a thin white band on the trailing edge only.	Vs	Mallards have a blue speculum bordered with thin black and broader white bands front and back.
Hybrid 1 (Grey-like)		Hybrid 2 (Mallard-like)
Head slightly mottled but conspicuous dark facial stripe. Olive/grey bill. More grey-like.	Vs	Head mottled and no facial stripe. Olive bill. More mallard-like.
Legs and feet more olive than orange. Slightly more grey-like.	Vs	Legs and feet more orange than olive. More mallard-like.
Wings have a greenish speculum with black borders and a thin white bands on both edges. More grey-like.	Vs	Wings have a bluish speculum with black borders and broad white band on back edge only. Slightly more mallard-like.

While this assessment is not absolutely definitive in terms of identifying genetic heritage, it is accurate enough to be useful for generally separating grey ducks from the hen mallards.