Aging and sexing immature Eastern Marsh is a total mystery to me. Primarily because I don't see them often enough or well enough and no two birds seem to look the same to my unattuned eye. All a bit off-putting. Thank goodness the only Pied I've seen in Japan was an adult male! However these few images of yesterday's bird, flying below the seawall, allow a better appreciation of the markings and structure than my usual blurred, against the light attempts.
There really isn't much help in the literature that I have access to but I'll put my head on the block and say this is a 2CY male.
|A wonderful surprise to have a bird come by just below eye level. By the time I jumped out of the car it was already slightly behind me but fortunately it swerved and dropped towards the field before resuming its course.|
Luckily for me something caught its eye at this point, it twisted sharply and swooped towards the field providing an excellent opportunity to see more features.
|It's easy to read too much into a single image but this shot captures the slight build indicative of male. The thin tarsai and bill also suggest male.|