Patience and preparation are important. Luck is indispensable.
Understanding your subject is never more important than when photographing animals. Even a little comprehension of the animals behavioural patterns can help you be ready for the shot when it fleetingly appears, and you will be better able to capture characteristic expressions or behaviours that make that animal special.
Behaviour varies between animals, even of the same species. One wild cat may be inclined to rest on the banks of a river and watch the boats go by, while another hides in the jungle and scuttles about behind the leaves where it can’t be seen.
The more you watch and observe the behaviour of an animal the more likely you will discern repeating patterns in their behaviour. A turn of the head every 40 seconds that gives you a single moment to shoot with desired composition, for example, or the way a particular species of dragonfly always returns to the same leaf.
Usually the biggest challenge with wildlife is just getting close enough to get a shot. A lot of wildlife in reserves and national park adapt to frequent visitors with indifference, at least while tourists are sitting in a car or a boat. Once you get out of the vehicle and start to walk towards them expect a flight response.
LONG AND FAST
For practical reasons a telephoto lens at 200mm is not very useful for wildlife photography unless the subject is trapped in a zoo. You will rarely be close enough to fill the frame with anything smaller than an elephant, let alone delve close into expressions or crop close into the face.
At 400mm you can expect better results provided you can get close enough. If you need to get into the range of 600mm you'll need a really expensive piece of glass, and a solid pack to get it into the wild. At these telephoto distances the additional problem is lack of clean light. In the jungle you may find that a 600mm lens is very dark and slow, and out on an open wetlands the effect of heat or haze can destroy any chance of a sharp image.
There's no substitute for getting closer. If you can shoot at or below 400mm you're going to get better images.
Shutter speeds are critical with animals, but can be hard to achieve in the field. There is no use employing a tripod to stabilise the camera at slow shutter speeds if the subject animal is running across the lens in a gallop. Your camera might be steady but the subject rarely is. The main advantage of a tripod, or monopod, is just to take the weight of a very large 600mm lens off your arms. You need a fast enough shutter speeds to counter the motion of your subject.
By dialling up a high ISO setting you can access higher shutter speeds and still have workable depth of field. In the days of film the use of high speed film (the equivalent of high ISO settings on a digital SLR) led to images that were grainy and of poor quality. Digital cameras have a huge advantage in this regard. Not only can you change the effective film ISO from one frame to the next, but you can expect excellent quality at the higher ISO settings provided there is good light available.
Noise problems with ISO on digital cameras in mostly a problem in conditions when there is not quite enough light to take the shot anyway. In daylight you can take the ISO to 1600 ASA and continue shooting at speeds of 1/1000th of a second or higher.
The corollary to high shutter speeds is retaining a medium f-stop. You lose depth of field very quickly with longer focal length, so even if your lens goes down to f/4 you may find the images are significantly sharper at f/8. The more affordable lenses are sharpest in the middle of the aperture range, not when shooting wide, so factor that in if you can't afford the heavy gear. Even on a 400mm lens at f/8 you can still expect a lot of background blur to help your subject stand out from the terrain. This is because on a telephoto lens the relative distance from you to the subject is normally much less than the background.
For animals that move horizontally through a scene, in a predictable and linear fashion, you may want to practice using the image stabilisation features of your telephoto lens. IS or VR modes usually operate either for panning or hand shake, so find out which works best for you and the situation you are shooting in. These systems are designed to reduce hand shake more than anything, but the panning stabilisation mode on some lenses are excellent for following wildlife as they move from left to right, or right to left.
The final technical tool that you might have available is an autofocus tracking mode (AI focus). Auto tracking simply means the lens will continue to follow the subject and keep it focused while it moves towards or away from you. The effectiveness of the tracking mode is usually limited by both the lens and the camera. Both need to be top notch to see good results.
It's worth getting someone to pose for you and practice tracking them through the lens as they move towards or away from you. This will give you some prior experience on what behaviour to expect from your lens when you get into the field. It is essential to get to know how your tracking system will respond before you can expect it to deliver in critical moments. Practice leads to confidence.
Once you get within shooting range of your subject, and have the camera setup with a suitable ISO setting and shutter speed, the next task is to wait for that moment of expression or behaviour that reveals something informative about the animal. The way they grab a branch, a quick peek over the shoulder, or maybe a stealthy pause before pouncing. Tracking focus coupled with shooting continuous frames gives you excellent tools to capture the optimum moment, that split second when a creature of the wild reveals a hint of it's character.
When shooting wildlife the most essential ingredient is patience. Waiting for that moment of expression, interaction or behaviour is what takes the image from technical to wonderful.
Look for more than just a subject, look for an insight into the behaviour or a pose that is most typical. All the standard composition rules still apply, especially the idea of giving some space to the subject so you get context and environment. You’re trying to place the animal into its habitat, not just grabbing ahead shot in the dead centre of the frame.
The best wildlife photographers are those who have the patience to wait in the wilderness for their subject, a depth of knowledge about the subject that helps them be in the right place at the right time, plus some insight into the behaviour of the subject. Getting a shot of wildlife is one thing, revealing something of the animals character and its environment is another.
Professionals do rely on local guides to help them get close species, and individuals. Guides who journey through the same park week after week, if not day after day, will have an intimate knowledge of some animals and their preferences at certain times of day or time of the year. Animals are unpredictable when there's a camera chasing them, but a good guide can take some of the guess-work out of the hunt.
I have been asked about shooting trained animals or wildlife in zoological parks. Certainly this takes much of the hard yards out of the task, and yes you can get good images that still look wild. This is a good way to practice your technique, but the sense of achievement is rather limited. If your aim is to have a few stock images to sell online, then you'll get what you want more easily from a contained facility. You and anyone else who pays their money for the same opportunity to shoot the same animal.
But if the art of photography and a love of seeing wild creatures in their native setting is what appeals most then the challenge of the wild becomes your call of the wild. The time spent following the trail of a wild animal is special, the thrill of that first encounter and the rush of adrenalin as you work your camera equipment to capture a fleeting moment.
An image earned is an image treasured.