Perhaps the best bird ringing blog in Cardiff....
Male - Broad White Submustachial Stripe6 - No contrast between Greater Coverts / Primary Coverts
I'm going to say adult female. Adult due to the apparently yellow breast and a lack of apparent contrast in the wing; female due to it lacking a black throat and perhaps the supercilium could be brighter.
No Black Throat probably because its outside of summer
And possibly because its a female in winter
My gut (without reaching for a book, and without seeing any the hand for many years!) feeling is to 5 it because it looks like there's a moult limit in the greater covers with a few new inner ones. The outer ones look browner than the possibly replaced median coverts.