Focusing on Moving Subject with Canon MKII AF

I am using Canon DSLR's, the 1DMKII and 5D, for shooting hummingbirds and eagles.
My problem is what are your recommendations as wildlife shooters in options for AF?
I use center point AF but no Custom Functions. I find 95% of my images result in the AF point being from slightly to way off the moving subject.
Will they Custom Functions involved with AF help?
Appreciate any advice/recommendations.
Dan

Really, to me 55% sounds pretty good considering the tiny fast subject. I'd be pleased with 20%. You honestly think others get 100%?


Kent in SD

on the 1d series, if you are dhootingn in al servo, there is a cf in there somehwere that allows a sensitivity adjustment that changes how fast the fp will move from the subject from high sensitive to low, sensitive, yo wil have to rtm on the specifics,, also, with humming birds full frame flying, you are going to really have to understand the jumpy ness in the subject may lead to less the high success,, but he eagles shouldnt be so bad, unless they are huge in the frame,, most of it is practise keeping the fp on the subject,, or, depeding on your back ground, you may consider lighting up the whole ring,,like against a clean blue bg,,

Thanks for your response Kim.
Dan