DrThunder88,
A supertelephoto lens can certainly help get the shot in some situations, where other lenses wouldn't be enough. That said, I'd think twice before buying one.
To begin with, understanding animal's behavior, and knowing how to track animals, are the main factors in getting close for tight shots. In fact, I'd say that my 300 f/4 is my primary lens for wildlife photography.
Secondly, they're HUGE, HEAVY, and EXPENSIVE. In practical use, they are even more of all three of these then the seem. This is partly because they require special carrying cases, tripods, etc., dedicated to them, to handle their weight... and that increases the size, weight, and cost of them substantially.
Thirdly, they're much more difficult to use than smaller lenses. Every bit of vibration is magnified many times. Some people have trouble even aiming them, due to the extremely narrow angle of view. And out of focus stuff simply disappears in the super shallow depth of field. They require holding them in special positions, using cable releases, keeping your shutter speeds high, etc.
If a supertelephoto lens is the right tool for your needs and ways of working, then nothing else will substitute... but they are not for everyone. Most people find them so inconvenient that they don't use them, and eventually sell them. They're generally not a good choice for casual hobbyists.