Prince William and wife Kate, on a week-long tour of India and Bhutan, rode in an open-topped jeep through the Kaziranga National Park in the northeastern state of Assam, spotting a pair of rhinos in a lagoon, as well as water buffalo and swamp deer.
The royal couple was keen to learn about efforts to combat poachers and how the wildlife affects villagers living near the park, spread across an area of 430 square km (165 sq miles).
"We felt good when the prince came to the park. We are lucky to interact with the prince," said forest ranger Salim Ahmad, adding that William had asked about the problems faced in the park and anti-poaching efforts.
The thick-skinned, one-horned Indian rhinoceros is one of five species in the world. Global conservation group WWF estimates that fewer than 3,000 of the animals survive today. They are found mostly in northeastern India, with a few hundred in neighbouring Nepal.
The rhinos in Kaziranga live in swamps, forests and tall thickets of elephant grass, where poachers hide before trapping them with poison, or just shooting them dead.
William and Kate have already visited the Indian capital, New Delhi and the financial hub, Mumbai. They travel to the tiny Himalayan kingdom of Bhutan on Thursday, before returning on Saturday to India's Taj Mahal - famously visited alone by his late mother, Princess Diana, in 1992.