After four decades of conservation efforts, Dudhwa National Park has marked a significant milestone by releasing its first one-horned rhinoceros into the open forests, with three more likely to follow.The release of a 12 to 15-year-old male rhino, named Raghu, took place on Thursday in the 27-square-kilometer rhino rehabilitation area (RRA-1), Field Director of Dudhwa Tiger Reserve (DTR) Lalit Verma said.This marks a significant step in the park's ongoing efforts to reintroduce the species to their natural habitat, Verma told PTI.Raghu was one of four rhinos selected for release after an extensive evaluation by experts and three female rhinos are expected to be released by Friday evening, he said.The release followed careful assessments by rhino experts from Assam's Kaziranga and specialists from World Wide Fund-India and the Wildlife Trust of India (WTI), Verma said.The experts studied the behaviour, health and overall condition of around 10 rhinos in the fenced rehabilitation area before selecting Raghu and the others for release, the field director said.On Thursday, Raghu was tranquillised, fitted with a radio collar to aid in tracking and monitoring and successfully released into the wild under the supervision of conservation experts, he said.This marks the beginning of a new chapter for the rhinos in Dudhwa, as they will be closely monitored for several months to assess their adaptation to the open forest environment, he added.Verma emphasised that the release was aimed at increasing genetic diversity within the Dudhwa rhino population.The park had previously launched the rhino rehabilitation program with just five rhinos in RRA-1, which now houses 46 rhinos. This success has also led to the establishment of a second rehabilitation area (RRA-2) at Bhadi Tal in the Belrayan range, where four rhinos have already been relocated.