So I have shot more than my fair share of mallards but this one is unique. For those that are still waterfowing in November you will pick up right away as you are a diehard like me...
I thought I had a 2024 metrosexual mallard for awhile... The boys say this one didnt count as a greenhead I begged to differ...
Anyway did some research very rare but an extremely old hen will lose her estrogen and start to go green. It is called an estrogenic bird but is a Hen... I am still saying it was a greenhead haha If interested University of Californa Davis Museum of Wildlife did a study on one identical. Pretty cool anyway.
Shot one this year that was nowhere near as green but definitely had maybe 30% green feathers on the head but the rest was all hen.
Very unique. First time finding out about this for me this year as well.
Yours is quite green - likely an older bird...
Could be a he/she but would say a very late hatch juvi male mallard rather than old hen because its got a drakes bill where the type of old hen you are describeing ive always seen with the orange and black bills that hens have.
Like most have said could be a very young male.
Could be a cross breed a Mexican Mottled Duck hen & drake mallard. The Mottled Duck drake & hen both look the same ...colors are very close to the Mallard hen plumage. pacific flyway duck. in any event very cool