One strategy for Piglantis level 1-9 is to loft the first White bird all the way to bomb the far-right pig. There’s a small “sweet spot” there, where the majority of the sand blocks will break. Then fire another White Bird into the leftmost stone triangle, toppling the remaining structure. If needed, clean up with one more White bird.
As an alternative, more repeatable, and high scoring strategy, try the “Swimming Egg” technique, first noted by @alfredhartojo. The video below yields 10,000 points more than above, and there is certainly room for improvement as well!