Mallard with green head at 4 weeks?

[Miss Lydia]

I have been observing a flock of Mallard ducks on a tidal part of the Mersey river in Nova Scotia.In the third week of January 2024 a tiny (smaller than pigeon sized) duck appeared in the flock.When I got a good look at him a few days later he has male head colours.A brown band on top then the distinctive green then more chestnut brown.I don't know how unusual the colouring is but I am very curious about the hen that hatched him in early January. It is now Jan 8 he can't be more than 4-5 wks old but he does seem to be growing.It must be rugged going with all the floating ice in the river.I hope he survives.He can also fly some.He just doesn't seem like other young ducks I see online.He is facing seasonal January weather. -5 to -11 C nights some snow and fierce winds.

It's not normal for Mallards to be hatching this time of year in Nova Scotia, is it?
I don't think they are evening hatching here yet.