I've witnessed my finches doing the same thing with their babies. It is cool to see.Yeah, pigeons (and doves) make it in their crops while sitting on eggs. It's partially digested seeds and is super digestible for the babies with allot of protein and fat. The babies need it for the first few days or they cannot grow correctly, I've tried raising pigeons from day 1 and had no luck, although after about a week they do well eating almost anything.