Wherefore, Waterhen

It looked like it's not as easy to sight the White-breasted Waterhens now.  I can hear these birds squabbling from time to time but to catch any foraging in the open seems increasingly challenging. 
When I saw this one I had to hide and when it sensed my presence it immediately retreated into the undergrowth.  As it was then it's difficult to identify for sure whether this was a moulting bird or simply an aged one.