濒危物种指所有由于物种自身的原因或受到人类活动或自然灾害的影响而有灭绝危险的野生动植物。一个关键物种的灭绝可能破坏当地的食物链，造成生态系统的不稳定，并可能最终导致整个生态系统的崩解。在过去的5个世纪内，约有900种动植物从地球消失（它们至少不会在地球这个星球上生存下去了）。而濒临消亡的物种现在超过10000种。那么，濒危物种用英语怎么说呢？
[图片0] What is endangered species 什么是濒危物种 An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. The International Union for Conservation of Nature (IUCN) has calculated the percentage of endangered species as 40 percent of all organisms based on the sample of species that have been evaluated through 2006. Many nations have laws offering protection to conservation reliant species: for example, forbidding hunting, restricting land development or creating preserves. only a few of the many species at risk of extinction actually make it to the lists and obtain legal protection like Pandas. Many more species become extinct, or potentially will become extinct, without gaining public notice. The conservation status of a species is an indicator of the likelihood of that endangered species not living. Many factors are taken into account when assessing the conservation status of a species; not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates, known threats, and so on. Internationally, 199 countries have signed an accord agreeing to create Biodiversity Action Plans to protect endangered and other threatened species. In the United States this plan is usually called a species Recovery Plan. Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife preserves, zoos and other conservation facilities. Captive breeding is meant to save species from going extinct. It is supposed to stabilize the population of the species so it is no longer at risk for disappearing. This technique has been used with success for many species for some time, with probably the oldest known such instances of captive mating being attributed to menageries of European and Asian rulers, a case in point being the Pere David’s Deer. However, captive breeding techniques are usually difficult to implement for highly mobile species like some migratory birds (. cranes) and fishes (. Hilsa). Additionally, if the captive breeding population is too small, inbreeding may occur due to a reduced gene pool; this may lead to the population lacking immunity to diseases. 从广义上讲，濒危物种(endangered species)泛指珍贵、濒危或稀有的野生动植物（wild fauna and flora）；从野生动植物管理学角度讲，濒危物种是指《濒危野生动植物物种国际贸易公约》（Convention on International Trade in Endangered Species of Wild Fauna and Flora，CITES，1973年3月3日签订于华盛顿）附录所列物种（species）及国家和地方重点保护的野生动植物。濒危物种可以分为绝对性(absoluteness)和相对性(relativity)两种。绝对性是指濒危物种在相当长的一个时期内野生种群数量较少，存在灭绝危险。相对性是指某些濒危物种的野生种群绝对数量并不太少，但相对于同一类别的其他物种来说却很少；或者是指某些濒危物种，在另外一些国家或地区可能并不被认为是濒危物种。