Whether it's climate change, loss of habitat or poaching, the endangered species list is ever changing for the better or for the worse.
Now, with several new species being added, there is a possibility that 2016 may be the last year for anyone alive to see the eight animals in the video above.
One in particular — the South China tiger — has not even been seen in the wild for more than 25 years. In the 1950s, the South China tiger population sat at around 4,000. Over the next few decades, they were hunted as pests before that became illegal in 1979. Now, scientists consider them to be "functionally extinct," meaning the population is no longer viable, according to the World Wildlife Fund.
Watch the video above to learn more.