While "ecology" encompasses the study of all living organisms and their interactions with each other and the environment, a more specific term for the study of animals in their natural environment is zoology.

Within zoology, the field of ethology specifically focuses on the behavior of animals in their natural habitats.

So, depending on the specific focus, you could use any of these terms to describe the study of animals in their natural environment:

* Ecology: The broader study of all living organisms and their interactions.

* Zoology: The study of animals.

* Ethology: The study of animal behavior.