Threatened
指面临危险或可能灭绝的状态，常用于正式语境。
例句：Many threatened species are protected by international laws.
Vulnerable
强调易受伤害或攻击，常用于描述生态脆弱的物种。
例句：The snow leopard is listed as a vulnerable species.
At Risk
通用表达，适用于人、动物或环境等多种场景。
例句：Coral reefs are at risk due to rising ocean temperatures.
In Danger of Extinction
直白描述“濒临灭绝”，语气强烈。
例句：The Javan rhino is in danger of extinction.
Imperiled
较文学化，意为“处于严重危险中”。
例句：Coastal habitats are imperiled by climate change.
On the Brink
习语表达，意为“处于崩溃或灭绝的边缘”。
例句：Some amphibian populations are on the brink of disappearing forever.