There is no substitute for an SLR when trying to take pictures of wildlife. Except for a trail camera.

A set and forget trail camera is wonderful but when you are actively chasing wildlife through the bush an SLR (preferably digital nowadays) is the best tool. Quite simply the flexibility of changing lenses and being able to see through the lens while shooting multiple frames beats anything else hands down.

Also the ability to dial in a fast shutter speed and aperture to get the right exposure is important.