A study by a team of experts from Wildlife Institute of India (WII) has found that a large population of northern Swamp deer (Cervus duvauceli) is in crisis due to a substantial shift of the river Sharda towards their habitat. The shift has been as close as to just about 0.9 km in 2001 from an earlier distance of 4.2 km in 1948.
Spread over about 200 sq km, Jhadi Taal, a marshy grassland on the river banks is surrounded by sal forests of the adjoining Dudhwa Tiger Reserve and is a stronghold of about 1,500 swamp deer, one of the five critically endangered species of deer in the world. WII experts Pradeep K Mathur and Neha Midha who have recently documented frequent alternations in channel length during the period found that it fluctuated remarkably from 10.77 sq km in 1948 to 18.63 sq km in 2001.
High run-off and siltation rates have been observed in the river during the last 40 years, primarily due to massive conversion of forest to agriculture for resettlement of people in Nepal in the upper reaches during the 1960s and 1970s, Pradeep told reporters. These changing patterns have led to frequent and sudden changes in the river course and in the last few years, the river channel has come dangerously close to Jhadi taal.
"The distance between taal and river channel is further reducing and it has reduced to less than 10 meters as observed in 2008. "For a critically endangered species like the swamp deer, this risk could prove fatal leading to their local extirpation in the Kishanpur sanctuary in the reserve," the study warns.
Highlighting the need to save the site, V Mathur, another WII expert says, out of the seven species found in India, Dudhawa is the last habitat for critically endangered five species of deer including Sambar, Barking deer, Spotted deer and the Hog deer besides Swamp deer. It needs protection as it is not only the habitat of the Barasingha, so called because of their antlers which have as many as 12 tines, but has also been recognised as an important bird areas holding species classified as globally threatened with extinction.
Besides, the ungulates are rich prey-base for the carnivorous like tigers and leopards there. If the region gets flooded, it will be total loss of habitat for Swamp deer and even if it gets only inundated or drained by cutting of bank by river, it would lead to sedimentation and siltation that would choke the lake, Mathur added.
Ultimately, Swamp deer would be forced to migrate in search for a new suitable habitat, making them vulnerable to poaching, if they move outside the protected area. The relative importance and effect of these man-made activities such as incessant land-use changes and river engineering works upstream with respect to the channel dynamics require attention, the report has said seeking immediate mitigation measures.