The human uniqueness clique in academia claimed that nonhuman animals are incapable of referring to anything outside themselves. When the primatologists Seyfarth and Cheney discovered separate Vervet Monkey signals for snake, eagle, and leopard, the humanists would have nothing of it. Fortunately their dogmatic assertions have been so thoroughly refuted with data that the perceived place of humans in the natural world is now more realistic and lest fantastic.
Songs and singing do not communicate about the singer's internal state, they communicate his desires and his mettle. But there are animal signals that do communicate the signaler's internal state; they are known as "calls." Today's sound is a call. It is saying, "I am hungry." That could be interepreted as a begging call if the juvenile who made it is still in contact with his parents. It can be interpreted as a pitiful plea for help if the bird is totally on its own. Or, of course, it might be an attempt at manipulation.
This was a young Red-tailed Hawk that I encountered on the Elkton BBS (Breeding Bird Survey). I never saw it, but I felt its pain.