Monopod really doesn't help - you push the shutter release and even with IS you can still see the camera shake when using a 100 to 300mm+ lens. What you will have going for you is that you will need a high shutter speed to capture the wild life but you will need to open up your aperture. I have the 75-300mm IS Canon lens and find the images are best with a tripod vs the monopod.
There is a very active Canon board on
www.dpreview.com
