I haven't been able to find any references on the internet about sparrows imitating falling leaves, but I have noticed in Washington State there are small sparrows that will often fly to the ground from a tree. What's interesting about this is they seem to mimic a leaf falling. They also, being very small birds, are about leaf size.
Observing this behavior is a very interesting form of camouflage, not only looking like a leaf while on the ground, but looking like a falling leaf so predators don't notice them flying down, which is great because this is when they are at their most vulnerable.
I don't see the same kind of behavior with crows or larger birds, they just land normally with their wings on either side, but these sparrows don't go down in a smooth fashion, they look like a leaf tumbling to the ground. I have only observed this behavior in Washington State, not in Florida where I also lived. However, it's possible that this behavior is common in other locations that I haven't experienced.