One factor that reduces the chances of re-discovering the white-eyed martin is the drastic decline in the numbers of swallows wintering at Bueng Boraphet, its only known site, from the hundreds of thousands reported around 1970 to maximum counts of 8,000 made in the winter of 1980–1981. It is not certain whether this represents a real decline or a shift in site in response to persecution. Other potential causes for the species' decline include the disturbance of riverine sand bars, the construction of dams which flood the area upstream and alter the downstream hydrology, deforestation, and increasing conversion of its habitat to agriculture. Very few swallows now roost in the Bueng Boraphet reedbeds, preferring sugarcane plantations, and, despite searching, the white-eyed river martin has not been found in other nearby large swallow roosts. Bueng Boraphet has been declared a non-hunting area in an effort to protect the species, but surveys to find this martin have been unsuccessful. Past surveys include several at Bueng Boraphet, a 1969 survey of the Nan Yom and Wang Rivers of northern Thailand, and a 1996 survey of rivers in northern Laos. A possible unverified sighting was reported in 2004.