Seagulls are a familiar sight in coastal areas and often inland, recognized for their distinctive calls and opportunistic behaviors. These adaptable birds are commonly observed soaring gracefully through the air, walking along beaches, or scavenging for food on land and the water’s surface. While often seen scavenging, their ability to swim underwater is frequently misunderstood.
Understanding Their Aquatic Foraging Techniques
Contrary to a common misconception, seagulls generally cannot fully submerge and swim underwater for extended periods like specialized diving birds such as cormorants or loons. Their body structure is primarily adapted for flight and surface-level interactions with water, making them too buoyant for sustained underwater swimming.
However, seagulls do exhibit various aquatic foraging techniques. They are capable of plunging from the air to snatch fish or other prey located just below the surface. Additionally, they can partially submerge their heads and upper bodies to grab items near the water’s surface. Their webbed feet, similar to those of ducks, are primarily used for propulsion while swimming on the surface. When preparing for a brief plunge, seagulls can compress their feathers, which helps to reduce the air trapped within their plumage, thereby decreasing their buoyancy momentarily to aid in a quick dip or lunge.
Reasons for Surface Dips and Plunges
The primary motivation for a seagull to interact with the water, whether through a brief dip or a plunge, is to acquire food. They are opportunistic feeders with a varied diet, often targeting small fish, crustaceans, and marine invertebrates that are close to the surface. Seagulls may also engage in “foot paddling” in shallow water, stirring up the bottom to bring hidden marine invertebrates to the surface for easier access. While foraging is the main reason, these quick, shallow interactions can also serve other purposes. Occasionally, a seagull might make a rapid dip or plunge to evade a perceived threat or to seek temporary refuge from a predator.
Limitations of Underwater Activity
A seagull’s aquatic capabilities are limited to shallow, brief interactions. Their “dives” are typically swift plunges from the air or quick dips from the surface, designed to grab prey that is readily accessible. They are not built for sustained underwater pursuits, lacking the dense bones and streamlined bodies of true diving birds that can withstand significant water pressure and reduce buoyancy for extended submerged periods. While seagulls can hold their breath for short durations, this is sufficient only for their brief foraging attempts, not for extended underwater travel. Although there are many species of gulls, none are adapted for deep diving or long periods spent beneath the surface of the water.