Here are some qualites you must posess to become a succesful wildlife photographer:
Passion: You know if you have the passion just by the rushes you get when you see the wildlife in their natural habitat.
Patience: You must have patience in order to take that spectacular photo. The more practice you get the better you will become. With wildlife photography, when you get ou in the field you will be able to observe and concentrate better when you have the patience.
Ability to achieve goals: Once you set a goal and achieve it, there is nothing stopping you!