Where's the water gone

Excuse me, can you tell me if this is the official bird bath. Well yes of course it is, why do you ask?
Because it seems there is very little water left in and the lady of the house only filled it up about ten minutes ago.
Ah well, you need to see my brother, sister, cousin, great uncle and all the rest of the family then.
Tsk, Tsk, not at all satisfactory, not at all.