Difference between "fell to the ground" vs. "fell on the ground"

What is the difference between the following two:

A young bird was flying in cold weather; after awhile, her wings froze up and she fell to the ground.

A young bird was flying in cold weather; after awhile, her wings froze up and she fell on the ground.

I understand that the first conveys the movement toward the ground, while the second merely says that she fell on the ground. But I am not sure which one to pick. Is there something more to the usage of these two prepositions?

This may sound obvious, but on emphasizes what was landed on. What if the bird didn't land on the ground? There's a good chance that you'd use on if the bird landed atop something, and in if the bird landed inside something.

The bird landed on the picnic table.
The bird landed on the hood of my car.
The bird landed on the roof of our house.

The bird landed in the back of my truck.
The bird landed in the birdbath.
The bird landed in the woods.

So, on the ground is perfectly fine, but you can also use to the ground, when you'd rather emphasize the direction of the fall, as opposed to the landing place. Both can be found in literature:

Shortly afterwards the bat again fell on the ground and this time was caught by another weasel.¹
A few hours later the bird fell to the ground with the arrow right through it.²

although, after running some Ngrams, fell to the ground seems much more common than fell on the ground,³ but there are some apparent exceptions.

¹from The Bat and the Weasel, as told in 365 Bedtime Stories by Christine Allison, 1998.
²from Sky Stories: Ancient and Modern by Roger Ptak, 1998.
³It should be noted that not too many Ngram results link to references of birds falling to (or on) the ground, but far more refer to people instead – sometimes in drunken stupors, sometimes from sheer exhaustion, sometimes in shows of repentence or thanksgiving, or even as a result of battle wounds.

You can fall to the ground only if you are in the air.