When Blake eats his buddy chow, he disembowels kernels of corn and swallows the sweet innards. The inside of a kernel is sticky, and a cockatiel is a messy eater.
One of Blake's least favorite activities is having his beak cleaned of quinoa (also sticky) and shreds of pea and corn guts, especially when his food has glued itself not just to his beak but to his jowls as well. However gently we rub a strand of jowl feather between our fingers, we sometimes detach not just the desiccated food from the feather but also the feather from the skin. This smarts and is undignified to boot.
Sometimes when he's munching on a single kernel of corn, working out the meat with his hammer tongue, the kernel jacket hooks itself on his lower mandible. This large thing he can shake off, leaving residue behind on beak and feathers to be polished away later by his parents. But while the kernel hangs there, effectively over his chin, he is Cornbeard.