Endangered species: The last animals of their kind

What are the rarest creatures in the world? This is a surprisingly difficult question to answer, but there are a few likely contenders, finds Rachel Nuwer.

Excerpt from article on BBC.com by Rachel Nuwer

Although she didn’t let on that anything was wrong, by the time the leaves began to change Suci’s keepers knew she was in trouble. The Sumatran rhino had dropped too much weight over the summer. By December, she had stopped playing with…