Animal photography is one of the most difficult fields of photography. However, with these explanations of vital skills, technical requirements and composition techniques it's easy to get started.
The most important skills you need for animal photography are patience and constant alertness. Unlike humans, who can be told how to pose (and especially how long to pose until you got the shot!), animals are hard if not impossible to control. Therefore, waiting for the right moment and then being ready to press the shutter is the base everything else stands upon.
Another essential skill is anticipation. The better you know how the animal will behave and react in its environment, the better you can plan your photo and take the necessary preparations, i.e. choosing the right lens and aperture.
Depending what kind of animal you want to take a picture of, the technical requirements vary greatly.
For example, shooting a pet or a savage animal in the wild is a makes a big difference. Your pet will probably not run away when you come a little closer, but savage animals such as deer instinctively flee as soon as they see or hear you or your camera shutter. Therefore, in order not to intimidate the animal and scare it away you should choose a telephoto lens, which allows you to take the shot from a greater distance. Camouflage is also an advantage.
If you like insects a macro lens will come in handy to discover the world of smaller life forms. Divers and underwater enthusiasts will go for a waterproof camera case or a special underwater camera.
Depending how fast the animal is moving you may want to freeze the action, e.g. when taking a picture of a bear capturing a fish, a dog jumping through a ring, or a flying insect at a flower. For action photography like this you require a lens with a low f-stop number, and a camera with a fast shutter speed and/or a high ISO setting.
If you do not want your photo to look like a lucky snapshot, there are several composition techniques to consider.
First of all, an animal photo taken from the human eye's level usually looks ordinary and boring. Therefore, if possible take the photo from the animal's eye level. Thus, the shot will become more intimate and interesting. You could even add a more dramatic effect by taking the shot from the perspective of the animal's prey.
Next, find the right balance between focusing on the animal and including the right amount of surroundings. Apart from zooming in or cropping the image to eliminate distracting surroundings you could narrow the depth of field, which will result in a sharp animal and a blurry background. You can maximize this effect by choosing a low f-stop number, a short distance to the animal and a high zoom level. This technique is particularly helpful when you go to the zoo and want to blur the metal bars of a cage.
Finally, make the photo special by capturing a special scene, which could be caused by interesting lighting, a distinctive prop, or something the animal is usually not doing. This will help your photo stand out from the huge crowd of animal photos.