Mallard/Call duck cross breed moulted once

[dwf96]

Over a year ago now my mallard/call duck crossbreed malted and lost his green head, everything I've read indicated that after a few months his green head should come back but it's showing no signs of returning, wondering if something is wrong with him or if this just happens?

 

[sourland]

I'll be very surprised if he does not molt into his nuptial plumage this autumn.

 

[dwf96]

I'll be very surprised if he does not molt into his nuptial plumage this autumn.

thanks for the reply, what would it mean if he doesn't get his green head back? it was around april 2020 when he lost it so it's been a while