Kathmandu, August 5 Annual reports of the last five years published by the Department of National Parks and Wildlife Conservation show that the number of one-horned rhinoceros dying due to natural causes in various national parks has been increasing. The report shows that a total of 24 rhinoceros died of natural causes, while one was killed last fiscal. The numbers of such deaths were eight in the fiscal 2015/16. Similarly, 13 rhinos died in the fiscal 2014/15. A total of 11 rhinos died due to natural causes and one was killed by poachers in the fiscal 2013/14, while 11 rhinos died in the fiscal 2012/13. The number of tiger deaths also increased notably in the fiscal 2016/17, reaching a total of eight. The number of such deaths in the previous four fiscals stood at three on an average per year. Tigers and rhinos in Nepal live in almost similar natural conditions. The DNPWC has not published the report of fiscal 2017/18 yet. Officials of DNPWC could not give reasons why the number of rhinos and tigers dying natural deaths was increasing. They said since the rhino population was increasing it was normal to see 25 natural deaths per year. DNPWC record shows that 52 rhinos were born last fiscal. Officials, however, said it was a matter of serious concern if the increase in deaths was a result of rise in the population of rhinos. DNPWC Director General Maan Bahadur Khadka said, “We have not conducted any study on how much area a rhino needs to survive in its most favorable situation. Until and unless it is proven that Chitwan National Park, where most of Nepal’s rhinos are found, is getting overpopulated we cannot take any measures to control deaths.” The Chitwan National Park is Nepal’s largest natural habitat for rhinos, while the animal is also conserved in five other national parks. The core area of CNP is 932 square kilometres with 750 square kilometres of buffer zone. All kinds of deaths, except for poaching, are considered natural. Deaths due to drowning, fighting, old age, diseases, attack by other animals are considered common causes of natural deaths. An average lifespan of a rhino is 40 years. The greater one-horned rhinoceros is a protected species and is listed as vulnerable on the Red List of International Union for Conservation of Nature.