What is It? - Animal Poop Question

There is some animal that keeps pooping on our front balcony and back porch roof. The poop is round, about 3/4 inch diameter, and yellowish/greenish. DH says that it is always round, never elongated. In order to get onto either location, the animal has to be able to climb to some degree or jump about 5 to 6 feet from the side slope to the garage roof. The prime suspect would be a housecat, but I thought that they always buried their business. Just about any Californian land animal except bear is possible in our yard.

raccoon, possum, color though ?/