You’ll need to research them. Some species share enrichment items, so you may sometimes have stuff available right away for new animals if you’ve done other research, but when you’re introducing new types of animals (like reptiles in a zoo that only has grazing herbivores), you usually need to do research.
This depends on game mode! You have to research for enrichment items in Franchise and Challenge modes. In sandbox you already know unless you turn on research in the settings.
Yes research each animal to unlock the items
You’ll need to research them. Some species share enrichment items, so you may sometimes have stuff available right away for new animals if you’ve done other research, but when you’re introducing new types of animals (like reptiles in a zoo that only has grazing herbivores), you usually need to do research.
If you go into the enrichment and type the spcecies of the animal in the search, it'll display everything you have that they can use.
This depends on game mode! You have to research for enrichment items in Franchise and Challenge modes. In sandbox you already know unless you turn on research in the settings.
If you play francise, you will take the research with you to new zoos, so you don't have to start every zoo from scratch.