The hungry heron and the cardinal (who does have feet) 
Nice feet on the Cardinal! Good image of him with his bounty! The feet turn out to mostly be a "must have", unless you're doing a head study or a 3/4 portrait of a bird.. I lost a local photo contest about 10 years ago, one of the judges told me that the only reason I lost was I didn't have the bird's feet in the photo... Crappiest part about that was, I cropped them out of the original! Occasionally it'll still happen, not too often though! I learned that lesson quickly! 
Thanks Ken. I'm learning a lot from you and others here on CR. That cardinal grabs the bread and flies off very quickly. Some shots are OOF or just gets his head, etc. I still want to learn how to do BIF. Ducks sometime fly low and fast over my house and @400mm, I can't find or track them before they are gone. What settings would you put on a 7D to capture BIF? Thanks again for all your comments.
Cheers 
You're welcome. Truly the key to catching a lot of great BIF images with the 7d is it's great AF system. It's not as good as the 5d3 AF system, it's very good though, many thought it to be ground breaking at the time, I was one of them...
Try the AF Expansion mode, it works pretty good to start on as you increase your skill and technique. Within the menu you can further extrapolate the AF system features. You can do this in Custom Function III menu. When you push the menu button on, it will be the next to the last menu to the far right, next to the green star.
From there, go down to C.Fn III: Autofocus/Drive. After that, I begin right at menu 1; AI Servo Tracking Sensitivity.
I choose to the mark in between slow and the middle. You will probably have better luck picking "Slow". (This doesn't mean that it's slow to pick up the subject your tracking, it means it holds on to it better once it's locked AF and surrounding items won't distract it as much)
Using your rear wheel, the next menu is #2; AI Servo 1st/2nd image priority. Pick #0, AF Priority/Tracking priority
Next menu, #3; AI Servo Tracking method. Pick #1, Continuous AF track priority
Next menu #4; Lens drive when AF impossible. I choose #0, Focus search on.
Next menu #6; Select AF area Select mode. Check or enable all of them. You may find that the "spot" AF is off, the little square with a smaller square inside of it, make sure that's checked on, it'll help you with birds in trees behind branches, etc...
Next menu #7; Manual AF pt. Select pattern. I choose #0, Stops at AF area edges.
#8; VF display illumination. I pick #0, Auto.
Menu #9; Display all AF points. I choose #0, Disable
Menu #10; Focus display in AI Servo/MF. I choose #0, Enable
Menu #11; AF-assist beam firing. I choose #0, Enable
Menu# 12; Orientation linked AF point. That's up to you, I select #1, Different AF points. Personal taste nothing to do with BIF...
Menu#13 Mirror lock up, well no I keep that disabled of course unless I'm shooting the moon or lightening or whatever, not for anything else..
Hope that helps with some of your settings for BIF captures with your 7D. Additionally, depending on your glass, you may want to make sure you have the lens in IS mode II for panning... Get in the habit of looking for birds that are flying toward you...
In the beginning, just shoot the freaking birds, don't worry if it's their arse, their face, or whatever. Just keep shooting them and practice keeping your focus as much as possible. It takes a lot of practice, especially handheld... Learn to adjust your 100-400mm while the bird is on wing... backing off a bit as they get too close so you keep the whole bird in the VF.
It really does take a lot of practice. After you get pretty good at getting the images sharp, take a vow not to shoot bird arse anymore. Even back in my F1 and AE1 film days, I wasted a lot of film on bird butts... With digitial, it's okay, do it for practicing technique. Like I said, just work on form and getting the bird sharp. Practice with larger birds like GBH, they fly relatively slow and are gorgeous...
As you improve, I found that I got cleaner, sharper images moving out of AF Expansion mode and more often into Single Point AF mode. That's me though, I'm certain it's not everyone's experience but I like to work on trying to keep my AF point on or close to their eye or head as much as possible. Please don't think you can't get clean, sharp images with AF Expansion, you most certainly can. I just the single point a tad more, although it takes much more effort and often times fewer keepers...
Good luck, let me know what you think of those settings if you decide to try them out...
All the best,
Ken
Oh, I keep my shutter speed fairly high for BIF my F/stop large and my ISO fairly high on the 7D. You may have good luck starting out in TV with a shutter speed of 1/800th to 1/2500th depending on time of day, with your iso set to Auto or 200-400 iso... it'll likely be a little hit and miss, but TV mode is a great place to start for BIF, unless you've already mastered manual mode... Then run with that. I shoot mostly in manual.
