"I request you to spare one pair of greater one-horned rhinoceros in exchange for one pair of Indian gaur," Chief Minister Jayalalithaa wrote to her counterpart in Assam, Tarun Gogoi.
Observing that the Indian gaur was the flagship animal in the state, she said Tamil Nadu had sufficient number of Indian gaur (Indian bison), which can be given in exchange to Assam.
The zoo in Vandalur did not have the representation of the one-horned mammal since 1989, she said.
Spread over 1,490 acres in the city suburbs, the Anna Arignar Zoological Park (AAZP) at Vandalur houses over 1400 individual animals consisting of 143 species.
Categorised as a 'large zoo' based on species diversity, number of endangered species and area, AAZP also receives a footfall of more than two million annually.