Pelicans are large aquatic birds recognized worldwide for their distinctive appearance, particularly their elongated bills and prominent throat pouches. Known for their presence in coastal and inland waters across many parts of the globe, pelicans exhibit remarkable adaptations that allow them to thrive in their diverse habitats.
Pelican Tongue Anatomy
Pelicans do possess a tongue, though it is remarkably small and rudimentary. This avian tongue is often described as tiny, stiff, and largely immobile, appearing as a mere vestige within their large oral cavity. Unlike the highly muscular and mobile tongues found in many other bird species, a pelican’s tongue has minimal involvement in manipulating food. Its diminutive size ensures it does not impede the swallowing of large fish, which form the bulk of their diet.
The reduced nature of the pelican’s tongue contrasts sharply with its overall body size and the demands of its feeding strategy. Its lack of significant function in prey handling is directly related to the bird’s specialized method of capturing and ingesting food.
Specialized Feeding Adaptations
The most striking adaptation of pelicans is their gular pouch, a large, stretchy, featherless sac suspended from the lower part of their bill. This highly elastic pouch functions primarily as a scooping mechanism, much like a fishing net. When a pelican identifies prey, it can expand this pouch dramatically to engulf both fish and water. The gular pouch is capable of holding a significant volume, up to three times the capacity of the bird’s stomach, sometimes containing as much as 3 gallons of water and fish.
Once fish are captured, the pelican performs a maneuver to drain the water from its pouch. It achieves this by tilting its bill downwards, allowing the water to flow out while keeping the fish securely contained. The flexible lower mandible, which forms the framework of the pouch, can bow outwards to maximize the opening for scooping. This efficient draining process is necessary before the pelican can swallow its prey, as consuming a large volume of water would make flight or further feeding difficult.
Pelicans employ various feeding techniques, with some species, like the Brown Pelican, known for spectacular head-first plunge dives from heights of up to 65 feet. Other species, such as the American White Pelican, often feed cooperatively on the water’s surface, herding fish into shallow areas before scooping them up. Beyond fishing, the gular pouch serves additional purposes, including providing partially digested food for their young and helping in thermoregulation through a rapid vibration known as gular fluttering, particularly on hot days.