Counting Rhino

Greater one-horned rhinoceros are restricted to small protected areas primarily in north-eastern India and Nepal. They are highly vulnerable, due to intensive farming, habitat loss, human population growth and poaching.

The grasslands of Nepal are not only the most fertile but also the most threatened in the world. Conserving the rhino will help conserve the grasslands, which also are home to other endangered species, such as the Bengal tiger, Gangetic river dolphin and Asian wild elephant.

The main objectives of the census were to determine the status and distribution of the rhinos and to assess the level of poaching threat on these populations.

The combined efforts of over 250 people, including biologists, observers, elephant staff and logistic crew, contributed to the sightings of 430 greater one-horned rhinos in Bardia and Chitwan National Parks.

The rhino census used a number of techniques in estimating the population numbers more accurately and to assess the threats on these populations and importantly their habitats. It gave the additional opportunity to obtain valuable data on the distribution and abundance of the primary invasive, Mikania micrantha, a creeping vine spreading rapidly in Chitwan National Park.

Each elephant carried one or two well trained observers, many of whom had experience from previous counts. Before starting the observers took part in a rigorous three-day training programme, learning how to record sightings using standardised forms and use the equipment involved.

The tracks of all elephant teams were logged and analysed at the end of each day to ensure all potential areas were covered. Communication in the field was essential to ensure rhinos were recorded accurately by the best placed team.

The team used GPS to track the rhino Hand-held radio sets proved to be very reliable in relaying messages from one elephant observation team to another. They also helped to maintain the distances between the elephants, approx 50m in dense forests and up to 200m in open grasslands.

The observers identified each rhinos using a range of features such as horn shape, ear tears, skin folds, deformities, body scars and tail shape. Binoculars were used where possible. At the end of each day, the data was carefully checked by observers to avoid double counts. The observers also cross checked their sightings with other observers sitting on elephant of either side.

It took a total of 3,108 elephant hours to complete the census sweep in Chitwan National Park and 328 elephant hours in the Karnali floodplain, Bardia National Park. A further survey of the Babai valley confirmed that no rhinos now existed in the valley, backing up an extensive survey in 2007.

ZSL Conservation Programmes Team member Dr Rajan Amin helped coordinate the census teams in the field. He said: ‘It is because of the hard work and professionalism of the team, particularly the people on the ground, that this has been such a success.

‘Our thanks go to the Department of National Parks and Wildlife Conservation who coordinated the operation with support from National Trust for Nature Conservation, WWF-Nepal and ZSL through the UK Darwin Initiative.’