There are tons of videos and blogs online about bird Photography here I will share with you what I have done and what works for me. It does take a lot of practice to be able to find your subject fast and following while shooting. Below is my two sense on bird photography.
Finding the subject in the viewfinder
One of the hardest thing for most photographers is to find the subject in your viewfinder with the lens at the strongest power. This is something you can practice at home. Find something in the distance and set you lens at the strongest power (ex 70mm-300mm lens set at 300mm) while looking at your subject bring your camera up to your eye without moving your eye or head and get the subject in your viewfinder. If you are unsuccessful at the strongest power of your lens back it down and then work your way back up to the strongest power. Some people can get it right away and others have a hard time but it is something everyone can do with practice.
Following birds in flight
This part of bird photography just takes practice behind the lens. When I am shooting birds in flight I do the following:
* Prefer to handhold for birds in flight.
* Have your shutter speed at a minimum of 1/500 I prefer 1/1250’s to freeze action faster is always
better when photographing birds.
* Also have a solid stance with my feet planted and my non-shutter arms elbow planted
into my side for stability and my shutter finger arm tucked in and camera held tight to
my face and as the bird flies twist at the waist.
Photographing birds requires patience and skill. If you are a beginner, try easier subjects like pigeons in the park or birds in the zoo before going out into the wild. Experiment with the shutter speed (faster and slower) until you know what will give you the effect you want. It’s also a good idea to be patient and let the birds come to you. You won’t get the perfect shot every time but with practice you will get better. Remember that you need to fill the frame as much as possible with the bird to make an interesting photograph, so zoom or telephoto lenses are a necessity.
Keep in mind these are the settings I prefer as you improve you will figure out your own style because after all photography is art and everyone sees it a different way.
Below is an image of the focus point I use when photographing birds in flight. Nikon it is referred to group focus and if the subject is not moving or a large bird I use single spot focus. Canon calls theirs Zone AF and you have 9 focus points.
Make sure you have your camera set to continuous focus this will help to keep you focused on a moving subject.
When focusing on birds try to get the eye of the bird but sometimes that is just not possible in this case focus on its chest. If your Aperture is at f8 the birds beak, eyes and body should be in focus.
Needs to be at a minimum of 1/500 but if light is available crank it up to at least 1/1600 if you can without sacrificing the image quality due to ISO.
When shooting birds I typically leave it in Auto just because you are in and out of shade chasing them. One thing to keep in mind when shooting in auto ISO you will need to use your exposure compensation to adjust for those really dark and white subjects.
Exposure Compensation it the +/- symbol that is on top of some cameras and others it in inside of you menu system on your camera. Get familiar with its location because it comes in very hand in getting the exposure correct inside of the camera save you time in Post processing of your images.
Last but probably the most important is your Histogram check your histogram on your photos and Shoot so the peaks are to the right but without reach the far right side. This will help in reducing the noise in your photos. Digital camera create noise in the shadows so if you reduce your shadows you will reduce the noise. Noise is the grain in your photos that create a fuzzy image even though your focus was spot on.
Last few tips
It is very helpful to learn bird behavior. This help in know what they are going to do.
Patience is another big tip waiting for that shot of a lifetime does not happen without waiting (well most of the time).
Go out and get some behind the lens time and experiment with different settings and find your style. Take my suggestions and try some of your own like adjusting the f/stop and get some nice bokeh backgrounds. Change up your shutter speed get some wings with blurred motion and a sharp face.