I have thought this idea for a DLC. And I have found the following animals:
- Guam kingfisher: It is only found in captivity within a conservation program. Only a captive population of Guam kingfisher remains of less than a hundred individuals. There are 3 subspecies
- Père David's deer
- Hawaiian crow: Although there are some individuals in captivity, any attempt to reintroduce them to their natural habitat has been stopped by the Hawaiian hawk that hunts them
- Spix's macaw
- Socorro dove: Currently its total population does not exceed 200 animals in captivity
- Alagoas curassow: More than 100 specimens survive in captivity
- Wyoming toad
- Scimitar-horned oryx
