You go looking for one species and end up finding another.
I went to a location by a river bank where I expected to find Reed Warblers.
I found a pair, but they mostly remained deep in tall reeds, emerging only a few times at speed flying across the river and disappearing in the thick bush on the other side.
All was not lost as on the other side of the river I observed a male Reed Bunting, which was collecting food and flying into the foliage on the bank.
Fortunately it pitched in the open each time before disappearing into the well hidden nest.