KOLKATA: Over 170 species of birds in the country are threatened, with eight new species added to the 2014 Red List prepared by the International Union for Conservation of Nature ( IUCN ).The eight species of birds newly added to the threatened list include the woolly-necked stork, Andaman teal, Andaman green pigeon, Ashy-headed green pigeon, red-headed falcon , Himalayan griffon, bearded vulture and Yunnan nuthatch, according to the list.The latest IUCN list also shows that the newly discovered small colourful bird Bugun Liocichla from Arunachal Pradesh is now "critically endangered", as compared to the earlier safer status.Relentless habitat destruction is regarded as the reason for decline in the population of birds, one of the best indicators of environment.The IUCN prepared its report based on studies conducted by BNHS-India, BirdLife International (UK) and other partner organisations.The list shows that a similar situation exists globally with 13 per cent of all bird species on the threatened list.The total number of species recognised by BirdLife in the 2014 Red List is 10,425.Among them 140 species are extinct, 4 extinct in the wild, 213 critically endangered, 419 endangered and 741 vulnerable, the IUCN list said.