Oriental Pratincole with Small Pratincole (Glareola maldivarum, Glareola lactea)

These were part of a, presumably, migrating flock of around 500 Small Pratincole with a few Oriental mixed in which had been resting on sand flats in the river bed for around a week.
I saw some drinking from and bathing in a large pool of rainwater but never saw them feeding.

There is a small resident population of Small Pratincole here which exhibited breeding behavior this year which stayed separate from the big flock.