You can use the appropriate shutter speed for the subject itself according to the movement pace, for example, 250 or 320 for a walking animal, 800 for a running animal or slowly flying bird, 1000 or 1200 for a more quickly moving bird and so on. The depth of field is a necessity in keeping deep enough field of view to included the subject detail in a shot, for example a heron flying may require an f stop of f10 to f13 or more to include its activity during movement. If I was you I would most likely use TAV mode and set the shutter speed and f stop yourself, and let the camera decide the appropriate ISO, unless you have the knowledge to master it yourself in Manual mode, which may be difficult in different lighting and movement situations.
Exaggerating your shutter speed and ISO will not aid you in getting shots, you have to regulate the use of them, which will allow you to apply the most appropriate ISO, or like I mentioned, just use TAV mode on your camera.
Sometimes you may want to allow a little room around your subject when shooting instead of just zooming in as close as you can get. That way when you shoot it gives you a bit of room to be able to track your subject and keep it well within the field of view.
Staying at a low number f stop such as F 2.8 will not give you the depth to attain detail of your subject in most cases, so as I mentioned above, use a higher number f stop. You may want to start with F8 for example, and if you find you need more depth for detail, use a higher F stop number. I would also recommend that you use "Spot" mode for your focus area setting, to allow for specific tracking of your subject(s).
You should have no problem getting nice shots without a tripod if shooting wildlife or other moving subjects. A 150-450 is capable of giving you nice shots without a tripod.
Last edited by C_Jones; 08-11-2019 at 05:23 PM.