Eurychelidon sirintarae is known only as a probable non-breeding visitor to one area of central Thailand. It was discovered in 1968 at or near Beung Boraphet lake, near Nakhon Sawan, and is known from 12 specimens collected among roosts of wintering swallow species. Rumors and one confirmed report suggested that many more had been sold in local markets (two unconfirmed reports date from 1986).
However, the bird has not been recorded with certainty since 1978, and is likely to have declined as a result of habitat degradation and destruction at its breeding areas and on wintering grounds--likely exacerbated by hunting and trapping at roost-sites. Some believe that the bird is still extant, but surveys are required in breeding areas to confirm this. Any remaining population is likely to be very small. Currently, the White-Eyed River Martin is classified as Critically Endangered.