Rather than filling the frame with just the animal, include some of the terrain or location in which it resides. This establishes a sense of place and educates the viewer about where and how the subject dwells. Refrain from fully zooming the lens or getting too close. While it feels great that an animal trusts you to get close enough, it may not make the best image. By all means, get in tight and create the head shot as explained above, but learn to back off a bit a go wider. A more common flow of events is to progressively let the animal gravitate closer to you or slowly enter its world to get the head shot. Should this be the scenario, even as you’re getting closer, think about the perspective of the shot if while you were close, you went wide and get a unique look to your wildlife images.