Last year I discovered this growing in the compost, It does not look like any hosta I have. Not even close, and it is small.
My hand is in the photo so show size.

I like it but I have never heard of birds bringing hostas.
They occasionally bring other flowers, my great blue lobelia is one.

'Undulata' one of the most common of all hosta.

Thank you , does it normally stay this small?

Undulata came with my house, and I have it all over my yard. Yes, it's pretty small when it's young. It gets larger as it matures. Just guessing (without looking it up, because I'm too lazy right now), I'd say the mature clumps I have are about a foot wide and maybe 8-10" tall. Leaves are approximately 3" wide by 4" long. I'd guess that it probably grows larger. My plants are nestled right up against some maple trees, so they don't exactly have the best growing conditions.

For some reason, I have undulata volunteers all over the place in spots I would never in a million years plant them--they just show up. I've always figured they had to be seedlings, because they're nowhere near the parent plants.