SAMBALPUR: At least 659 Indian Bisons or Gaurs were counted in the first-ever census of the animals conducted in Debrigarh Wildlife Sanctuary.
The census was conducted on November 12 and 13. Of the total population, 210 (30 per cent) are juveniles. The 659 Bisons were approximately seen in 52 herds including female gaurs with their calves.
The herd size in the sanctuary varies from 8 to 33. The juvenile population indicates a fast-growing or thriving population in Debrigarh sanctuary. The Indian Gaurs in Debrigarh are massively built and strong bulls weighing up to 1,500 kg. They are one of the major herbivores of the sanctuary.
The landscape-wide census exercise was taken up by direct observation technique/direct count from 6 am to 6 pm by 53 census units comprising 114 team members.
The census was conducted on foot with systematic surveys along forest roads, animal trails, water bodies, grasslands and meadows, saltlicks etc. While estimation, detection probability played a crucial role, the survey was conducted for two days.
Each beat in the sanctuary was stratified into small segments which were covered by separate teams to avoid overlapping. The tourism zone in Debrigarh sanctuary has recorded the presence of more than 100 Gaurs in six herds including few massively-built adult bulls. Three herds in the zone have more than a dozen Indian Bisons.
However, the population structure and age-sex classification could not be ascertained because of difficulty in identifying the seen animals due to dense forest areas and presence of tall grass.
But detection probability was around 80 per cent for estimation of total population, which implies that 20 per cent of the population could have been missed due to restricted visibility and group movement.
Indian-Bisons/Gaurs are predominantly seen on the foothills of Debrigarh in the meadows with abundant food crops like grass besides browsable plants like bamboo, siali, palas, as well as fruits, leaves, bark, young shoots etc.
DFO, Wildlife, Anshu Pragyan Das said, “The one-third young population of gaurs is an example of the healthy breeding space created post relocation of 400 families residing inside Debrigarh sanctuary two years back, which have now also turned into nutritious meadows for bisons.”