Nice one Joy, somehow I missed this one earlier in the month! He's a cutie!
Seems silly now, but for what it's worth I think the cast shadows were fine to start with, but I'd probably have included some of that shadow mix on the animal (ignoring the photo and just concentrating on unifying all parts of the painting).
We don't have chipmunks here in the UK, so it's wildly exotic to me that you have them on your patio!