BrainBoozz on Instagram: "When a pelican yawns or opens its bill wide, the full size of its mouth is most striking. The enormous, flexible beak of a pelican, particularly the lower pouch known as the gular pouch, can enlarge dramatically, demonstrating how amazing this bird's eating apparatus truly is. In order to help the pelican catch prey while fishing, the pouch can expand to accommodate many litres of water or even a huge fish when it yaws. The thin skin of the pouch becomes nearly transluc