Have you ever gone to a National Park that boasts of it's wildlife but when you get there with camera in hand there is no sign of the little critters? I have done this a number of times. With the exception of Yellowstone I have returned with lots of pictures of the sights but no animals. If I did happen to come across some of the four legged residents of the parks the pictures would end up being reminiscent of those taken of the Loch Ness Monster (too far away and unrecognisable).
My solution for my recent craving for wild life was a trip to the Calgary Zoo with the family.