I have SO many pictures I could post of them from every stage of life. I go a little crazy with the pictures lol. Since my flock is mixed all year long, I can't say for 100% certain they are runner mallard mutts. I only had two drakes at the time these guys' eggs were laid, a mallard and a WH. I had several laying females, which complicates things. I had a pekin, Cayuga, WH and fawn/white runner laying at the time these guys eggs were laid. But based on the egg size/color and which females were laying at the time, I have a pretty good idea of what mixes they are.
This is Mr. Duckie. He doesn't have the runner shape, so I'm not actually certain he's runner. Definitely mallard tho, his shape just screams mallard. Below is his adult plumage:
And this is his adolescent plumage. He looked just like a regular malard, except the dark points of his feathers were gray, not black. He's on the left:
This is Dickie, and he is for SURE half fawn/white runner, and I am almost 100% positive he is half mallard. He clearly shows the runner shape and stance, although not as upright. and he lacks the rosy breast like Mr. Duckie has. His adolescent plumage was much like Mr. Duckie's, with gray points instead of black. This is his current adult plumage:
Here they both are together:
Do you have runner/mallard mutts? I would love to see more