One thing to keep in mind when photographing hummingbirds, that you will need to take a whole lot of photos to get some 'keepers". We subscribe to the bi-monthly magazine "Birds & Blooms" who feature hummingbirds several times a year, including the current issue. They often provide suggestions from photographers on shooting hummingbirds, and one thing that always pops up is you need to shoot hundreds of photos to get a few keepers. When you think of it, these little two inch critters are zipping around all the time, and trying to get a properly composed let alone focused image is quite a challenge. I've been trying to photograph them for several years, and our local season is fairly short. For the longest time we'd only have one female bird hang around the wife's garden and our feeder, so I didn't have too many chances. We were blessed this year with up to four of them, three males and one female. Now to see if they stick around for me!
I've given up on trying to use autofocus on my 75-300mm zoom, it just focuses too slow, and if the bird moves out of the central focusing point, the camera often tries to focus on what's way behind the critter. And manual focusing isn't all that great either, as they rarely keep still for me. Having plants they like around helps, and I shot quite a few birds around some bee balm flowers my wife planted. These have mulltiple trumpet blossoms which keep the birds interested, but they also zip from one blossom to the other, making it difficult.
Here's one from a few years ago showing its little feet that you are interested in:
I needed to use my auxiliary flash for this one, shot at 1/1250, f/5.6 and ISO 100, at 300mm. Without the flash most of the bird would have been in shadow. As I mentioned previously, my Canon 430EX flash can be set at high speed synch, allowing it to fire at higher shutter speeds.
Can't wait until this season really gets started, want to try out my Sigma 170-500mm lens on the wee ones!