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Location India, Arunachal Pradesh
Central coordinates 96o 50.00' East  27o 50.00' North
IBA criteria A1, A2
Area 200,000 ha
Altitude 1,000 - 5,000m
Year of IBA assessment 2004

Bombay Natural History Society

Site description Chaglagaum-Denning-Walong is a large wilderness in the Lohit district of Arunachal Pradesh, along the border with China (Tibet). Chaglagaum is a proposed reserve forest, while Denning is reserve forest in the west of Chaglagaum. The River Lohit forms the eastern and southern boundary of this IBA. The northern mountain ranges along the China border remain snow-covered for the greater part of the year. Two villages, Goiliang and Chaglagaum, are within the Chaglagaum proposed reserve forest. The Goiliang village lies in the southeast part of the area while Chaglagaum is in the north. The Lohit, Dallai, Daf and Tiding are the main rivers. Other important rivers and streams are Haramachi, Kuronmachi, Daren, Kajop, Kazomiyu, Ami, Telua, Tasit, Chengai and Katso. The vegetation is of Subtropical Broadleaf and Conifers up to middle elevation, above which occurs Temperate Forest of Broadleaf and Pine and other mixed conifers, especially in the north. Further up occurs Alpine and Sub-alpine Scrub.

Key Biodiversity 

AVIFAUNA: A total of 259 bird species are reported from this area, of which 159 are Biome-restricted species (Hazarika 2003). This site falls in the Eastern Himalayan Endemic Bird Areas (Stattersfield et al. 1998) and covers three biomes due to its altitudinal variations. In Biome-5 (Eurasian High Montane- Tibetan and Alpine) 13 out of 48 Biome-restricted species have been found till now. Seventy out of 112 Biome-7 (Sino-Himalayan Temperate Forest) species were recorded, which proves that good Sino-Himalayan Temperate Forest is still surviving in this IBA. Similarly, the site has extensive tracts of Sino-Himalayan Subtropical Forest (Biome-8). BirdLife International (undated) has identified 95 species in this biome, out of which 64 species were recorded by (Hazarika 2003).

Hazarika (2003) has reported Himalayan Monal Lophophorus impejanus from this site, and the adjoining Dichu Reserve Forest (another IBA). He had two sightings near Taramko East, in the upper part of Chaglagaum. One sighting was of three individuals and another of two birds. Several confirmed reports from higher reaches were given to him. This is a large, conspicuous pheasant, more often seen in the Western Himalaya. According to Ali and Ripley (1987), this pheasant is replaced in the Eastern Himalaya by Sclater’s Monal Lophophorus sclateri. However, Singh (1994) has also noted it from from east Arunachal. This proves that it has a much wider distribution than known earlier.

One of the most important sightings in this IBA is of the Wood Snipe Gallinago nemoricola, a Vulnerable species, according to BirdLife International (2001). Two birds were seen on Ganing river and a single bird in Kajop river area. Singh (1994) has recorded this species on the tract between Migging-Pango-Nugguing-Tuting and Keegut.

The Rufous-necked Hornbill Aceros nipalensis and Beautiful Nuthatch Sitta formosa are also globally threatened species (BirdLife International, 2001). Both depend upon dense broad leaf forest, which is under threat all over northeast India. A single Rufous-necked Hornbill was observed at Denning RF, north of Lohitpur (just outside Chaglagaum). A flock of eleven Beautiful Nuthatch was observed upstream of Tiding river on the slope of the riverbank, in the southwest part of Chaglagaum (Hazarika 2003).

OTHER KEY FAUNA: Due to its inaccessibility, the forest is well preserved and is a true representation of climax vegetation. This is the abode of temperate animals such as Red Panda Ailurus fulgens, Asiatic Black Bear Ursus thibetanus, Goral Nemorhaedus goral, Serow Nemorhaedus sumatraensis, Musk Deer Moschus chrysogaster and Takin Budorcas taxicolor. Other important species recorded are Barking Deer Muntiacus muntjak and Leopard Panthera pardus. Snow Leopard Uncia uncia is reported above 3,000 m (Haridasan et al., 1999). However it is not confirmed.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Wood Snipe Gallinago nemoricola breeding  2004  present  A1  Vulnerable 
Rufous-necked Hornbill Aceros nipalensis resident  2004  present  A1  Vulnerable 
Snowy-throated Babbler Stachyris oglei resident  2004  present  A1  Vulnerable 
Beautiful Nuthatch Sitta formosa resident  2004  present  A1  Vulnerable 
Rusty-bellied Shortwing Brachypteryx hyperythra resident  2004  present  A1, A2  Near Threatened 


IUCN habitat Habitat detail Extent (% of site)
Forest   -
Shrubland   -

Acknowledgements Key contributor: Asif Hazarika.


Ali, S. and Ripley, S. D. (1987) Compact Edition of the Birds of India and Pakistan. Oxford University Press, New Delhi.

BirdLife International (2001) Threatened Birds of Asia: The BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

BirdLife International (undated) Important Bird Areas of Asia. Briefing Book 103 pp. Unpublished.

Haridasan, K., Borang, A. and Singh, P. (1999) Baseline survey of Biodiversity in high priority biologically rich areas of Arunachal Pradesh. State Forest Research Institute, Itanagar.

Hazarika, A. A. (2003) A survey on the Biome-restricted avifauna of Chaglagaum proposed reserve forest. Report submitted to the Bombay Natural History Society, Mumbai. Pp.54

Singh, P. (1994) Recent bird records from Arunachal Pradesh, India. Forktail 10: 65-104.

Stattersfield, A. J., Crosby, M. J., Long, A. J. and Wege, D. C. (1998) Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. BirdLife Conservation Series No. 7. BirdLife International, U.K.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Chaglagaum - Denning - Walong. Downloaded from on 25/10/2016

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