Great choice to get into bird photography, always fun and all sorts of photography to choose form, Bird Portraiture (The bird on a stick photo), Bird Action shots, (Birds doing something with movement, landing etc like below) and Birds in flight. The Easier ones are the Bird on a Stick photo, thou that involves patients and to a point stoking you subject, or waiting for the subject to come to you, (In my case this is where my mushroom photography comes in, I take the mushroom shots and the birdlife acclimatises to me and comes back around. A couple of quick tips have your shadow point at the bird and ideally the wind coming from your back, that way the bird will be facing you, They are not fans of having their feathers blown inside out. The sun at your back also puts the bird in the right light. Always watch your back grounds try and get an even coloured back ground and one that contrasts the subject if possible, you need to be able to isolate your subject, depth of field also helps with isolation. That’s a few quick tips. Happy to answer any questions I can. I think you’ll find pretty quick that a 70 to 200 won’t be long enough even with a 1.4 extender. Having said that I’ve got some great shots earlier on with a 24 to 105, so it is possible, but you will soon be wanting for a longer lens. So if your starting out, maybe look for a Sigma or Tamron 150-600mm if you’re going all out birding, the 70 to 200 is a great lens and I have one of those as a well, it’s just not long enough I find for most of my birding work. A great resource o birding photography is @ScottBourne , I’ve added a link to his latest web site which has plenty of bird photography tips, He is also running a new photography pod cast so worth checking out as well. Scott was on Cake a while ago not sure he still pops in here, but I'm sure if your check out his web site you'll find plenty on useful info there, I'm happy to help out with any of your questions, if I can. As for faster frame rate its nice to have at times, My 7Dmk2 can do 10 frames a second, but you need good light as my lens is f6.3 at 600 so a dark lens so with out good light the shutter speed comes down and then the camera can't keep up with the ten frames a second, most times I shoot at lower frame rates, so then it comes down to knowing your subject and what they are going to do. Most birds have favourte purches so if they start in one place they will probably coem back there at some time so set up and wait is one trick, a lot of birds will also preform certain bodily functions relief before taking off so thats always a sign they are about to fly, so knowing that you cna predicy when they are about to take off and capture that moment. there is a lot of practice and you'll have plenty of missed shots bird tails in shots with the rest of the bird cut off etc, but over time that will come. I spend a lot of time practicing shooting eratic swallows skiming accross the lakes in my local botanic gardens just practicing, once I can get these then I'm pretty confident I can get most everything else. So don't feel dissapointed and don't expect a high keeper rate at first, it will come with time. You'll eventually want to start looking at gettig out of Auto settings as well or at least use exposure compensation, otherwise you'll have a lot of bird silhouettes, I shoot full manual and also have my camera set up for back button focus. Hope some of this helps, Check out Scotts web site for aload of useful info, and sing out if you have questions.