Bird on a Wire

The proverbial bird on a wire, and it seems that whenever I see a bird perched on a cable like this, it seems to be something that keeps the bird from moving too much so I can get some nice close-ups. The little sparrow would move its head around a bit but otherwise stayed in one spot as I took these images. I notice it has tiny little feet, and I'm almost surprised they can support the bird standing on a wire this way, but I know they are also quite light, so the proportion of its weight isn't like a human's.