Note

Classified as Critically Endangered on the IUCN Red List of Threatened Species, the White-bellied Heron Ardea insignis is the world’s rarest heron and is currently facing a rapid decline in population across its range and it is mainly attributed to habitat degradation and disturbance (BirdLife International 2015). It has a small global population of 60 individuals of which 28 are found in Bhutan, 23 in Myanmar and 7–8 in India (Price & Goodman 2015). It is possibly extinct in Bangladesh and Nepal (BirdLife International 2015). The White-bellied Heron is protected as a scheduled species in Bhutan under the Forest and Nature Conservation Act of 1995 (DoFPS 1995).

On 18 April 2016, a group of researchers and the second batch of nature guide trainees at the Ugyen Wangchuck Institute for Conservation and Environment (UWICE) under Department of Forest and Park Services (DoFPS) sighted an individual heron along the Drangmechhu River in Jamkhardrang area (27024’00.1”N & 91033’04.2”E, 746m) under Tashi Yangtse District (Image 1). The bird was sighted perching on a rock in the middle of the river. There were boulders, sand and gravel by the bank of the river. The forest on the opposite side of the river was mainly sub-tropical Chir Pine Pinus roxburghii forests with few trees of Cassia fistula and Vitex negundo.

In Bhutan, the White-bellied Heron is observed in large rivers and lakes with Chir Pine trees adjacent to it (RSPN 2011). Their habitat preference differs from elsewhere in the present and former range of the species, where river systems adjacent to subtropical broadleaved forest are recorded as their main habitat (BirdLife International 2015).

The authors observed the bird for about 15 minutes during which the bird showed no activity and then it flew and landed on the river bank. After a brief halt of two minutes, it flew down the river and disappeared. Our observation represents a major extension of the known distribution of the species and is the easternmost known distributional record in Bhutan. Previously, the species is known from 11 sites in central and southwestern Bhutan (Table 1).

Latest developments have resulted in an increase in habitat disturbances and degradation to its prime habitats through conversion of land to agriculture and settlements, hydroelectric power constructions, road widening, and sand quarry (BirdLife International 2015). The primary threat observed at the site to the species is the construction of the Kholongchu Hydropower Dam.

Many conservation agencies in Bhutan especially the Royal Society for Protection of Nature (RSPN) and the DoFPS have been working on the protection of the species and its habitat. Population and observation surveys and conservation awareness campaigns are being conducted every year (RSPN 2011; MoAF 2015; RSPN 2016a). After the first success in 2011 on the captive rearing of a White-bellied Heron and its successful release in the very same year, RSPN has started the construction of White-bellied Heron Captive Breeding Facility Center at Changchey Dovan in Tsirang District in early 2017 (BirdLife International 2015; RSPN 2017). A young juvenile was also fitted with a satellite transmitter in 2016 and it has helped to provide important insights on its movement and behaviour (RSPN 2016b).

Further detailed studies are highly recommended to study the extent of distribution, the level of threats which the species faces across Bhutan and urgent mitigation measures which need to be adopted to prevent a further decline in its population.

References

BirdLife International (2015). Ardea insignis. The IUCN Red List of Threatened Species 2015: e. T22697021A79123798. http://doi.org/10.2305/IUCN.UK.2015 4. RLTS.T22697021A79123798.en

DoFPS (1995). Forest and Nature Conservation Act 1995. Department of Forest and Park Services, Ministry of Agriculture and Forests, Royal Government of Bhutan, Thimphu Bhutan.

MoAF (2015). Bhutan today has 28 White-bellied Herons thriving. www.moaf.gov.bt/> Accessed 05 June 2016.

Pradhan, R., T. Norbu & P. Federick (2007). Reproduction and ecology of the world’s rarest Ardeid: The White-bellied Heron (Ardea insignis) in Bhutan. 31st Annual Meeting of the Waterbird Society. 30 October to 3 November 2007, Edifici Historic, Universitat de Barcelona.

Price, M.R.S. & G.L. Goodman (2015). White-bellied Heron (Ardea insignis): Conservation Strategy. IUCN Species Survival Commission White-bellied Heron Working Group, part of the IUCN SSC Heron Specialist Group.

RSPN (2011). Research on White-bellied heron. http://www.rspnbhutan.org/research-on-white-bellied-heron/> Accessed on 05 June 2016.

RSPN (2016a). White-bellied heron conservation. http://www.rspnbhutan.org/white-bellied-heron-conservation/> Accessed on 05 June 2016.

RSPN (2016b). A step towards saving the last White-bellied herons.http://www.rspnbhutan.org/a-step-towards-saving-the-last-white-bellied-herons/> Accessed on 06 June 2016.

RSPN (2017). Construction of White-bellied Heron Captive Breeding Center begins. http://www.rspnbhutan.org/construction-of-white-bellied-heron-captive-breeding-facility-center-begins/> Accessed on 02 February 2017.