Pelicans are large and distinctive water birds, easily recognized by their massive bills and unique throat pouches. These birds are found globally across warm regions, inhabiting coastal areas, estuaries, and inland waterways on every continent except Antarctica. Their imposing size and unusual appearance often spark curiosity about their behaviors.
Pelicans’ Natural Diet
Pelicans primarily consume fish. They are highly adapted for hunting aquatic prey, using their keen eyesight to spot fish from above the water’s surface. The specific types of fish vary by species and location, ranging from small schooling fish like anchovies and sardines to larger fish such as carp and mullet. In their natural habitats, pelicans locate their prey by observing movements in the water, sometimes individually or cooperatively.
The Pelican Pouch and Feeding Strategy
A pelican’s most recognizable feature is its gular pouch, a large, elastic throat sac that hangs beneath its lower jaw. This pouch functions as a highly efficient fishing net, not for storing food for later consumption.
When a pelican captures prey, it opens its bill and expands this pouch to scoop up fish and water. After scooping, the pelican lifts its head and tilts its bill downward, allowing water to drain. This process is quick, ensuring that only the fish remain in the pouch before they are swallowed whole. The extensible skin of the gular pouch can hold up to three gallons of water, serving as a temporary holding area for captured fish.
Explaining Apparent “Omnivorous” Behavior
The perception that pelicans “try to eat everything” stems from observations of their unique feeding method and opportunistic tendencies, rather than a truly omnivorous diet. Pelicans can exhibit behaviors that might be misinterpreted.
Pelicans are opportunistic feeders and may occasionally consume other small aquatic animals, such as crustaceans, amphibians, or even small birds, especially if fish are scarce. Some species have been observed eating ducklings or gulls, particularly during periods of starvation.
When pelicans scoop up fish, they inevitably take in water, along with debris or non-food items like pebbles or small pieces of trash. These items are expelled with the water and are not intentionally consumed or digested. Like many animals, pelicans may investigate unfamiliar objects with their bills, which can appear as if they are attempting to eat them. This curiosity is part of their exploratory behavior.
In murky waters, a pelican might mistake a non-food item for prey, leading to accidental ingestion. Some pelican species may also scavenge discarded food or scraps from human activities, contributing to the perception of a broader diet. These instances are exceptions to their specialized fish-eating habits and often result in regurgitating indigestible items.
Variations in Pelican Feeding Habits
While the fundamental mechanism of using the gular pouch to capture prey is consistent across species, pelicans display diverse hunting strategies. The Brown Pelican, for example, is known for its plunge-diving technique, where it dives headfirst from heights of 10 to 20 meters into the water to catch fish.
This high-impact method is effective for stunning fish near the surface and involves adaptations like air sacs to cushion impact and rotating their bodies to protect internal organs. In contrast, the American White Pelican feeds while swimming on the surface and rarely plunge-dives.
These birds often engage in cooperative fishing, working in groups to herd fish into shallow waters or tight clusters by swimming in a line or semicircle and beating their wings. This cooperative herding allows them to scoop up concentrated prey more easily. Different feeding environments and techniques mean a diving pelican might accidentally encounter debris from the seafloor, whereas a surface-feeding pelican might inadvertently scoop up floating vegetation or other items present in shallow waters where they hunt.