I think no, because the head are different ,and most important, the Mallard female has blue
feathers in the "specular" (I don't known the exactly word in english ,sorry) above the green feathers.
Is it a Madagascan Meller's Duck (Anas melleri)? They have a longer, flatter beak than the mallard & have green speculum feathers bordered by white (sexes are similar).
A quick internet search suggests it's definitely not a Yellow-billed duck, male or female.
