Ardea insignis is known from the eastern Himalayan foothills in Bhutan and north-east India to the hills of Bangladesh, north Myanmar and, historically at least, across west and central Myanmar (BirdLife International 2001). The first confirmed record of this species in China was made in 2014 in Lushui County, Yunnan Province on the border with Myanmar (S. Chan in litt. 2014). It may also occur in south-east Tibet, China, but is now extinct in Nepal. Birds may visit the Brahmaputra lowlands in winter. Although historical reports suggest it was previously common in Myanmar, it has evidently declined throughout its range given the paucity of recent records. Most of the few recent records come from sites in Assam and Namdapaha in Arunachal Pradesh, India (Maheswaran 2007, A. Choudhury in litt. 2016), a few sites in Bhutan, and parts of Myanmar. In Bhutan, there is a small population of 30 known individuals (with six juveniles) as of July 2007 (Pradhan 2007), with the total national population unlikely to exceed 50 individuals (Pradhan et al. 2007). The birds were observed along the Phochu, confluence of Phochu-Mochu, Punatsangchhu, Kamechu (Digchu), Zawa, Ngagshina and Burichu confluence (Pradhan 2007), with another recent sighting along the Drangmechhu River (Wangdi et al. 2017). Six active nests were recorded in Bhutan in 2007, two from a new site, and by 26 July 2007 they held six chicks in total. Due to natural forest fires, three nests were abandoned.  A further three active nests with five chicks were recorded in 2009, although only three chicks remained on a subsequent visit (Anon 2009). Six breeding sites from two rivers of central Bhutan have been recorded, and the eastern part of the country has not been thoroughly surveyed (Pradhan 2007). The species has also been reported from the Thim Chhu, Lungtenphu (C. Feijen in litt. 2009).  A massive hydroelectric scheme may have recently caused its expiration from the Sunkosh Valley (K. D. Bishop in litt. 2012). Two adult birds were recorded in Phibsoo Wildlife Sanctuary, Sarpang in February 2014 (Anon. 2014). The annual survey of White-bellied Heron in Bhutan reported 22 birds in 2014, an increase from 2013 when 20 birds were recorded (Anon. 2014).

In Myanmar, the 21,700 km² Hukaung Valley tiger reserve (the largest area of suitable habitat within the species’s range) is believed to support approximately 26-28 individuals (Price and Goodman 2015), and Hpon Razi Wildlife Sanctuary and Hkakabo Razi National Park hold small populations. White-bellied Heron has been recorded along rivers elsewhere in Kachin State, such as the Nam Sam Chaung, although little is known about its status in these areas (A. W. Tordoff in litt. 2006).  Despite an increase in survey effort within the species’s range in Myanmar there has been no corresponding increase in the number of records and the species was apparently absent from large areas of suitable habitat (J. Eames in litt. 2006, D. Wilson in litt. 2006). One recent repeat survey failed to record the species in an area where it had been seen in 1998 (D. Wilson in litt. 2006).  The findings of field surveys have also been supported by reports from local people which suggest that the species has declined in the region in recent years (D. Wilson in litt. 2006). This evidence suggests there may be fewer than 250 individuals remaining (J. Eames in litt. 2006, D. Wilson in litt. 2006).  In north-east India, a few individuals are regularly seen in Namdapha National Park, Arunachal Pradesh (Maheswaran 2007). Up to six individuals were recorded in Namdapha Tiger Reserve in January 2014, this was followed by a breeding pair at the same location in March 2014, a first for India (Mondal and Maheswaran 2014). The nest observers had to leave the area before they were able to confirm whether the pair had successfully raised a brood, however a second visit was planned for July-August 2014. Further nest building was noted at this site in 2015, though nesting appeared to fail following a storm (G. Maheswaran in litt. 2016). Records from other sites are sporadic and there are no recent sightings from a number of former sites including Jamjing Reserved Forest, Dibru-Saikhowa National Park, Kaziranga National Park, Nameri National Park and Pabitora Wildlife Sanctuary (A. Choudhury in litt. 2012. 2016). The most recent sightings in Assam were a lone immature bird in Kanamakra area of the western buffer of Manas Tiger Reserve in 2007, two birds from Subankhata Reserved Forest, Baksa district of the eastern buffer of Manas Tiger Reserve in 2010 and an immature individual near Dibru-Saikhowa National Park in 2015 (A. Choudhuryin litt. 2012, 2016, G. Maheswaran in litt. 2016).