Animal photography is a specific genre of photography which deals with capturing images of animals in their natural habitat. Urban birds and animals living in their natural habitat (cities/towns) will also qualify as animal photography. It also includes animals and birds which live in areas which are less urban. Animal photography requires a combination of tools and techniques that involve several other genres of photography.
Sports photography, portrait photography and low light photography are some of the genres that are cannibalized to form what is the core of animal photography. You also need to have a good understanding of animal behavior, because at the end of the day that is what will help.
Even before knowing how to shoot, you have to know where to go to find what you need to shoot. Plus, animal photography techniques would require you to master low light high-speed photography scenarios, often requiring you to use high-resolution cameras with superior high ISO performance and paired with fast lenses.