IN378
Dibru - Saikhowa Complex


Site description (2004 baseline):

Site location and context
This complex covers Dibru-Saikhowa National Park, Poba Reserve Forest, Kobo chapori (river islands) proposed reserve forest, Amarpur chapori, Maguri and Motapung beel (lake), and the adjacent riverine tract of the Brahmaputra and Lohit rivers. The Dibru-Saikhowa NP proper covers 34,000 ha in the districts of Tinsukia and Dibrugarh in eastern Assam. It is 13 km north of Tinsukia town. It is also a Biosphere Reserve. The area is known as a major haunt of the globally threatened White-winged Duck Cairina scutulata, Black-breasted Parrotbill Paradoxornis flavirostris and Marsh Babbler Pellorneum palustre. In 1986, the Government of Assam declared Dibru and Saikhowa Reserve Forests as Dibru-Saikhowa Wildlife Sanctuary, covering 64,000 ha which also included Amarpur chapori and the adjacent riverine tract of the Brahmaputra and Lohit rivers. Subsequently, the area was upgraded to a national park. However, at the time of final notification as a sanctuary and as well as a national park, only the reserve forest areas were included. Maguri and Motapung beels in Tinsukia district, although very important for the conservation of waterfowl, are outside. Similarly, Poba and Kobo, important biodiversity sites, are located north of the Park and are in Dhemaji disrict. We have included all these adjacent sites in one IBA. Dibru-Saikhowa has the largest salix swamp forest in northeastern India. Tropical Moist Deciduous, Tropical Semi-evergreen, Evergreen Forests and grassland forms the main habitat type. The original vegetation of the Park was tropical rainforest, but a large part sank by a few meters during the earthquake in 1950, causing significant geomorphological changes. Due to regular flooding, the rainforest gradually gave way to deciduous forest and swamps (Choudhury 1998). The relatively remote Amarpur area, on the northern side of the Brahmaputra river, not included in the Park but is a part of the wider Dibru-Saikhowa Biosphere Reserve, has significant areas of tall grass, which are largely absent in the other areas of the Park. The Amarpur peninsula within the Biosphere Reserve covers about 3,000 ha. It is generally low-lying and much of it is flooded during the monsoon season (Allen 2002).

Key biodiversity

AVIFAUNA: Dibru-Saikhowa complex is very rich in bird life, with more than 310 species already identified (Choudhury 1994, 1997). It is one of the sites in the northeast where highly endangered and elusive White-bellied Heron Ardea insignis is seen. Choudhury (2002) saw a lone bird in Salbeel area in November 1993. The two Critically Endangered Gyps species of vultures were not uncommon during 1992-94, but now both are very rare. During a survey in October 2001, no Oriental White-backed Vulture Gyps bengalensis and Slender-billed Vulture Gyps tenuirostris were sighted (Choudhury 2002). Two more Endangered birds that could have significant populations in this IBA are White-winged Duck Cairina scutulata and Bengal Florican Houbaropsis bengalensis. Four nests of White-winged Duck have been recorded. Most of the recent sightings have been listed in Choudhury (1996) and historic records in Green (1992). The Bengal Florican is a rare resident of the grasslands. There are many sight records from this IBA (Choudhury 2002). Another Endangered bird of which we have few confirmed records from India is Nordmann’s Greenshank Tringa guttifer. Choudhury (2002) reports a lone bird near Dighaltarang on the bank of the Dangori river in November 1993. Baker (1904) had reported nest of Masked Finfoot Heliopais personata in July at Dighaltarang but Choudhury (2002) could not find any evidence of existence of this species. The tall wet grasslands of Dibru-Saikhowa are important for many threatened and non-threatened species. Stattersfield et al. (1998) have identified three endemic species in the Assam Plains Endemic Bird Area: Manipur Bush Quail Perdicula manipurensis, Black-breasted Parrotbill Paradoxornis flavirostris and Marsh Babbler Pellorneum palustre. The first species is historically not found in the floodplains of the Brahmaputra but the remaining two endemics are found in this site. Choudhury (2002) sighted the Marsh Babbler a number of times, mainly in Toralipathar in 1992-1994. The Black-breasted Parrotbill lives in dense tall grass so sighting it is not easy. Nevertheless, Choudhury (2002) was able to see two individuals in association with the Rufous-necked Laughingthrush Garrulax ruficollis in Amarpur on December 1993. The sighting of the Black-breasted Parrotbill is significant as there are hardly any recent records from anywhere in its range (Choudhury 1997). Another notable record from this IBA is sighting of a pair of Sarus Crane Grus antigone, the first sighting of the species in north-east Indian for several decades. The birds were of nominate race antigone and this record has extended their range by 500 km. The Grey Treepie Dendrocitta formosa and Oriental Turtle Dove Streptopelia orientalis were found to be resident at lower altitudes (c. 100 m) (Choudhury 1997) than previously recorded by Ali and Ripley (1987). Jerdon’s Babbler Chrysomma altirostre, the globally Vulnerable species of tall wet grasslands, is common in the more extensive habitat in Amarpur (Allen 2002). Puff-throated Babbler Pellorneum ruficeps, is quite common in the forested areas at Kolomi, and was seen in the same habitat of low bushes at the forest edge as Marsh Babbler; it was also found in Amarpur (Allen 2002). The tall grass of Amarpur is of great value for many Restricted Range grassland birds (Allen 2002) Dibru-Saikhowa is among the most important wintering sites in Assam of the Black Stork Ciconia nigra (Choudhury 1997). Excellent reports and papers on the bird life of this site by Choudhury (1994, 1997, 1998, 2002), show that this IBA has 2 globally Critically Endangered, 5 Endangered, 13 Vulnerable, and 11 Near Threatened species. The site qualifies A1 (Threatened Species), and A2 (Restricted Range criteria). The list of Biomerestricted species is too long to be included here. It is one of the best known IBAs of Assam.

OTHER KEY FAUNA: Other fauna includes Asian Elephant Elephas maximus, Tiger Panthera tigris, Leopard P. pardus, Sloth Bear Melursus ursinus, Slow Loris Nycticebus coucang, Pigtailed Macaque Macaca nemestrina, Rhesus Macaque M. mulatta, Assamese Macaque M. assamensis, Capped Langur Trachypithecus pileatus, Barking Deer Muntiacus muntjak, Hog Deer Axis porcinus, Flying Squirrel Petaurista sp., Gangetic River Dolphin Plantanista gangetica, Monitor Lizards Varanus bengalensis, V. salvator, various turtles including Kachuga sylhetensis, snakes including Indian Cobra Naja naja and Indian Rock Python Python molurus. Assam Roof Turtle Kachuga sy lhetensis was also recorded for the first time in the area, constituting the easternmost limit of its distribution (Choudhury 1994).

Pressure/threats to key biodiversity
MAIN THREATS: Logging; Erosion; Poisoning of waterbodies; Cattle grazing; Disturbance to birds; Firewood collection.

The main conservation issue is diversion of a channel of the Lohit river through Ananta nullah, a small channel in early 1990s. This has resulted in widening of the latter channel into a wide river, which ultimately made the National Park an island. Large areas have been eroded in the process. The next major issue is the presence of two large forest villages inside the Park. Most of the forests have been heavily exploited for timber, and very little dense forest remains. Fishing activities cause a considerable amount of disturbance, and there is heavy grazing pressure from domestic livestock. The peripheral areas are being reclaimed for agriculture, and there has been considerable encroachment by the forest villagers. A large portion of the area is under threat because of a natural shift in the course of the Brahmaputra river. Local people use chemical pesticides for fishing in the Park as well as Maguri and Motapung beels, which kills large number of life forms. Encroachment in Kobo chapori has taken alarming proportion.

Acknowledgements
Key contributor: Anwaruddin Choudhury.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Dibru - Saikhowa Complex (India). Downloaded from https://datazone.birdlife.org/site/factsheet/dibru--saikhowa-complex-iba-india on 22/11/2024.