There are two speeds of interest - shutter speed and what I'll group as camera speed.

The shutter speed is the first - too slow and you'll get blur. Sports mode should be OK for this but if it isn't you'll need to select a shutter speed priority mode and then select a fast shutter time yourself. To start with turn the ISO up to at least 800 and probably more to get faster shutter speeds for a given light level - you can always back it off after practice. What shutter speed you need depends on the bird, it's behaviour, the focal length and how steady you are. A soaring vulture might be fine at 1/500, maybe even less if you use IS or a tripod. Wing beats of a small bird are almost impossible to freeze. Hummingbirds are the extreme example - even at 1/4000 they're not sharp.

Camera speed includes focus speed (which you can help with by prefocussing with a half press of the trigger), and shutter lag. This is the time between pressing the trigger and the sensor recording the image. It varies between cameras, but if you're tracking the bird's movement very well, it shouldn't be a problem - unless the bird changes direction. So you need some luck here - more luck than on an SLR as the shutter lag is likely to be more.

You need to get plenty of practice on your specific camera so try going to a park or local nature reserve and taking photos of the common birds. Start with big, slow moving things (most gulls, waterfowl) and move on to smaller, more nimble species (many passerines, but still stick to the ones that fly out in the open).