You can unlock animals such as the Asian Black Bear,
Przwlaski's Wild Horse, Albino Gorilla, Chinese Alligator, etc.
Research the strongest fence and go to the bottom of the list
of animals. All the ones after the Chinese Alligator are the ones
that can be unlocked unlock during scenarios. Rainforest Zoo has
the Przwlaski's Wild Horse and Asian Black Bear. Condition:Critical
has the Albino Gorilla and Asian Black Bear.