Pelicans are large, distinctive water birds often seen in viral videos attempting to swallow objects that seem impossible, such as small birds or oversized prey. This behavior gives the impression that pelicans will try to eat nearly anything. This perceived indiscriminate eating habit is rooted in a unique combination of their specialized anatomy and opportunistic hunting instinct. Understanding the mechanics of their feeding and the biological design of their bill provides the necessary context for this behavior.
Unique Structure of the Pelican’s Bill and Pouch
The pelican’s iconic, elongated bill features a massive throat sac, technically called the gular pouch. This highly flexible, featherless area of skin connects the lower mandible to the neck. Contrary to common belief, the pouch is not a permanent storage container for food, but functions as a temporary dip net for catching prey. When fully extended, the gular pouch of a large species like the Australian Pelican can hold up to 13 liters of water, significantly more than the bird’s stomach capacity.
Once a pelican scoops up water and potential prey, it draws the pouch to its chest, tipping the bill downward to drain the water. The lower jaw consists of two slender, weakly articulated bones that allow the pouch to expand drastically, facilitating the scooping action. This permits them to briefly encompass surprisingly large items, leading to the observation of a pelican appearing to swallow something too large.
Primary Diet and Specialized Feeding Strategies
Pelicans are primarily carnivorous and depend on fish as the bulk of their diet, supplemented by other aquatic life such as crustaceans, amphibians, and small reptiles. They are highly successful predators, with different species employing distinct hunting methods to secure their prey. For instance, the Brown Pelican uses a dramatic plunge-diving technique, diving headfirst from heights of 10 to 20 meters to stun and scoop up fish like anchovies and menhaden.
In contrast, white-plumaged species, such as the American White Pelican and the Great White Pelican, typically feed while swimming on the water’s surface. These species often engage in cooperative feeding, working in groups to herd fish toward shallow water before simultaneously scooping them up. This coordinated strategy focuses on capturing small to medium-sized fish that can be swallowed whole. Since the pelican’s tongue is greatly reduced, chewing is impossible.
Instinctive, Non-Selective Hunting
The perception that pelicans try to eat everything stems from their highly opportunistic nature and the non-selective action of their scoop-net hunting. When a pelican is actively feeding, especially during periods of scarcity, their instinct is to scoop anything that appears to be a potential meal and then assess it. This non-discriminatory scooping action, coupled with the pouch’s ability to briefly hold large objects, occasionally results in the temporary capture of non-food items, such as garbage or small birds.
The physical limitation is not the initial size of the object scooped, but whether the item can be successfully manipulated and passed down the relatively narrow esophagus. Since they must swallow prey whole, they are sometimes filmed attempting to swallow small ducks or gulls, particularly when fish is scarce. These attempts are driven by the biological imperative to maximize caloric intake from any available source before the item is deemed too large or inedible and rejected.