Ducks possess a range of aquatic abilities, but whether they can go underwater depends heavily on the specific species. Ducks have specialized into distinct foraging niches, reflecting different feeding strategies. While all ducks are proficient swimmers, some are equipped only for surface-level activity, while others are built for deep, prolonged dives tailored to their environment and food source.
Dabblers Versus Divers
Waterfowl are categorized into two main groups based on feeding behavior: dabblers and divers. Dabbling ducks, such as Mallards, feed in shallow water by tipping their bodies forward, submerging only their heads and the front half of their bodies. This “bottoms-up” posture allows them to reach aquatic plants, seeds, and invertebrates near the surface without fully going underwater. Dabblers prefer calmer, shallower bodies of water.
In contrast, diving ducks, including species like Scaup and Canvasbacks, are built for full submersion and deep-water foraging. They pursue prey like mollusks, fish, and roots found far below the surface. They use powerful webbed feet to propel themselves entirely underwater, often disappearing from sight for extended periods. Divers generally favor larger, deeper lakes and coastal waters.
Physical Adaptations for Underwater Movement
A duck’s successful aquatic life is supported by several specialized anatomical features, particularly in diving species. One adaptation is the uropygial gland, or preen gland, located near the base of the tail. This gland produces an oily secretion that the duck spreads over its feathers, creating a hydrophobic coating that repels water and prevents saturation. This oil is essential for buoyancy and thermal regulation underwater.
To manage buoyancy for a dive, ducks actively compress their feathers against their bodies, expelling trapped air and reducing lift. Diving ducks also tend to have higher body density compared to dabblers, facilitating a quicker descent. The structure of the legs and feet provides the necessary propulsion, with diving ducks having larger webbed feet set farther back on the body. This rearward placement is awkward for walking on land but provides maximum leverage and power for foot-paddling propulsion underwater.
Limits of Submergence and Propulsion
While diving ducks are capable of impressive feats, their submergence is constrained by physiological limits, primarily the need for oxygen. Most foraging dives for species like pochards and ruddy ducks last between 10 and 30 seconds, though a duck can remain submerged for a minute or more. The body manages this breath-holding through the diving reflex, which slows the heart rate and redirects blood flow. This process prioritizes oxygen delivery to the central nervous system, while other organs rely on anaerobic metabolism for a short time.
The depth a duck can reach is also limited by pressure, varying significantly by species and food source. Many common diving ducks forage in relatively shallow waters, typically reaching depths of two to six meters where aquatic vegetation is abundant. Specialized sea ducks, such as Long-tailed Ducks, can dive to much greater depths, occasionally exceeding 15 meters to hunt for mollusks and other benthic prey. Ducks dive primarily for foraging or to evade predators, and once the dive is complete, they cease paddling and allow natural buoyancy to bring them back to the surface.