Dear friends, this bird has been called a Booted warbler, a Blunt-winged Warbler and a Paddyfield Warbler by different people. Close to river in mixed grass and bush. What is your vote and why? Or is it none of the above? Any one of those would be very rare in Kathmandu valley.
It's a Booted Warbler Arend just completing its moult. A combination of structural features including rounded head and rather small bill, short under tail coverts and medium length, notched tail (t1 < t2) rule out Paddyfield and Blunt-winged Warblers. The images aren't the sharpest but it is clearly an Iduna; combination of face pattern, bill structure and contrasting dark centred tertials, darker remiges and rectrices eliminate Sykes's.