The latest survey has confirmed the presence of at least 46 one-horned rhinos in the Dudhwa Tiger Reserve of Uttar Pradesh, officials said on Tuesday. Found mainly in the Indian sub-continent, the greater one-horned rhino has a single black horn about 8-25 inches long and a grey-brown hide with skin folds, according to the World Wildlife Fund (WWF).

The rhino project in the Dudhwa reserve, located on the Indo-Nepal border, was launched in April 1984 with just five rhinos relocated from Assam. The rhinos were reintroduced in the terai region where they had gone extinct about a century ago.

The adaptive environment, healthy habitat, rich flora and fauna of Dudhwa suited the re-introduced rhinos and their population grew to 38 in 2018 and 46 in 2023. The last head count was taken up in 2022 but it remained inconclusive as 25 per cent of the rhino habitat area could not be accessed due to heavy flooding.

The survey, conducted from March 15-17, was done in the 41 sq km stretch of the Rhino Rehabilitation Area. Dudhwa forest officials, experts from Wildlife Institute of India and the WWF participated in the exercise.

"The 46 rhinos sighted in Dudhwa included 40 rhinos in 27 sq km Rhino Rehabilitation Area-1 in south Sonaripur range and six in RRA-2 which is located in Belrayan range," said Rengaraju Tamilselvan, the deputy director of Dudhwa Tiger Reserve. He said the gender of six rhinos could not be ascertained.

He said WII experts have collected samples of the rhinos for molecular analysis, which may help in determining shifts in the community due to environmental changes.

Field Director B Prabhakar said the survey was carried out "through the specific physical features and the unique ID provided to each rhino." He said seven teams — five in RRA-1 and two in RRA-2 — patrolled the rhino area riding on the back of elephants for the census.

The deputy director added that the total rhino area at Dudhwa Tiger Reserve was divided into several grids and separate teams carried out physical sighting of rhinos in their assigned areas and recorded the distinct physical characteristics of each individual rhino for its accurate identification.

Apart from rhinos, Dudhwa is also an ideal home to royal Bengal tigers, swamp deer, sambhar, cheetal, wild boars, wild elephants, alligators, crocodiles, over 400 species of birds, reptiles besides a number of medicinal plants and rare herbs and orchids.