Blyth's Reed Warbler (Acrocephalus dumetorum) 1cy.
Here are wing formulas for those 3 species. Top left Blyth's Reed
Warbler (A.dumetorum), top right Marsh Warbler (A.palustris) and
below Reed Warbler (A.scirpaceus).
Notice the differences in emarginations, notches and the length of P2.
Colour of the claws is a very good character between Reed
and Marsh Warblers. Reed Warbler(left) has a strong contrast
between very dark upper and bright yellow under parts of the claw.
In Marsh Warbler (right) this contrast is not so distinct because
the upper part of the claw is not so dark. Normally Marsh also
has clearly shorter claws.
