Watch this video by PhotoRec TV for an assortment of great tips and tricks on how to photograph wildlife.
Photographing wildlife is not easy and can be extremely difficult. Unless you're in a zoo, wildlife are usually not prone to stay around humans. It can sometimes take days of patience and tracking an animal just to get one decent click of the shutter when in the field.
One obvious and easy way to capture wildlife images, which PhotoRec TV mentions, is to use a longer lens. Unless you want to capture the environment wildlife is in, using a longer lens will give you the ability to photograph wildlife without having to be right next to them. Many telephoto lenses can be pretty expensive, though. So, an entry-level lens or 70-200mm with a teleconverter is a good alternative.
One trick that isn't mentioned but is extremely helpful is to seek out simple backgrounds. Most often, the best wildlife images have lots of negative space or backgrounds that aren't distracting. Messy and chaotic backgrounds can cause the main subject to become drowned out in an image. You want to make the subject stand out and be the focus of the image.
Another crucial aspect of wildlife photography is to be respectful of your subjects. If you're in the field, you're in another creature's home. It's important not to invade the space of wildlife and to make sure they're comfortable at all times. Capturing a photograph of a wild animal is never worth the stress or unusual behavior you could cause it by being too close. Sometimes, you have to know when to walk away.
Watch the video to learn more tips and tricks, and feel free to leave your own in the comments below.