The Department of National Parks and Wildlife Conservation (DNPWC) is conducting a census of wild water buffaloes (Bubalus arnee), locally known as Arna, in the Koshi Tappu Wildlife Reserve (KTWR) from Wednesday.

Laxman Prasad Paudyal of the DNPWC said 65 people, including the reserve staff, technicians and volunteers, will be deployed to count the Arna population starting from April 11.

The reserve area has been divided into six blocks—Haripur, West Kushaha, Prakashpur, Bhagalpur, Patthari and Badgama— for the census.

“The census will be conducted based on the traditional head-count method. Since Arnas live in groups, the enumerators will be following their herds and count them individually,” said Poudyal.

When the KTWR was established in 1976, there were 63 wild water buffaloes. The latest census in 2016 had put their number at 432.

“The reserve’s Arna population has gone up over the years. We hope to see their number increase this time as well,” Poudyal said.

The state has recognised Arna as one of the 27 protected species.

Arnas are comparatively less vulnerable to poaching, unlike rhinos and tigers. Officials say human settlement around the reserve and habitat fragmentation are some of the challenges facing Arna conservation efforts.

“As the people living close the reserve let their domestic buffaloes (Bubalus bubalis) in the reserve for grazing, there is a possibility of inter-species breeding which could impact the population of indigenous wild water buffaloes,” Paudyal said.

And then, there is also the concern of the KTWR Arna population losing their habitat due to floods that occur almost every year during monsoon.

The KTWR was the only natural habitat of wild water buffaloes in country until the authorities in 2017 translocated 13 of these endangered bovine species to the Chitwan National Park (CNP). It was an attempt at creating a new protected area for Arnas.

The initiative did not fare as well as the officials had anticipated, because four Arnas died shortly after they were introduced to the CNP.

Arna is listed as endangered species in the International Union for Conservation of Nature (IUCN) Red List. There are around 3,400 of them in the world.