When worldbuilding, I am trying to fill my world's nature with a lot of dangerous monsters. However, there was something I realized I forgot to do, and something that I notice many fantasy creators forget: Balancing fictional wildlife to match ecosystem.
In many fantasy worlds and urban fantasy, you will see many natural environments with normal animals, but also mythical beasts and monsters coexisting. Unfortunately, for consistency, they do not have their own prey to continously survive.
While this may be a really small detail, I am trying to make it so that monsters can exist in my world, BUT there is a consistent ecosystem for them to survive in. What my question is: How can I edit the environment, so that fictional creatures (deadly monsters in my case) can be like normal animals in it?
Note: For one solution, I am already doing it: Adding on more fictional creatures for the monsters to feed off of. While that is for a few environments, I am trying to make environments where they appear like regular forests and deserts, but can handle extra fauna, much like how those creatures exist in real-world mythologies.