Ducks are often observed gliding across the water’s surface. While their surface movements are well-known, their ability to dive beneath the water for food or safety is frequently underestimated. These birds possess specialized adaptations that allow them to explore the underwater world.
The Mechanics of Duck Diving
Ducks have anatomical and physiological features for underwater excursions. Their bodies are streamlined and compact, which helps reduce drag as they move through water. Strong, webbed feet are positioned further back on their bodies, acting as powerful paddles for propulsion. Some species also use their wings for additional thrust underwater.
To manage buoyancy, ducks can compress their feathers against their bodies, expelling trapped air and making themselves less buoyant before a dive. Their respiratory system includes a network of nine air sacs that store air, allowing them to breathe underwater. Physiologically, ducks exhibit a “diving reflex” when submerged, which involves a dramatic reduction in heart rate and redirection of blood flow to essential organs like the brain and heart, conserving oxygen for prolonged dives.
Measuring Dive Depth and Duration
Diving capabilities vary significantly among duck species. Most diving ducks typically forage in waters between 6 and 10 feet deep, with dives commonly lasting 10 to 30 seconds. However, some species are capable of much more impressive feats. For instance, sea ducks frequently feed in waters 10 to 65 feet deep.
The Long-tailed Duck is particularly notable, with recorded dives lasting up to 230 seconds and reaching depths of over 160 feet (49 meters). White-winged Scoters have been observed diving to 196 feet (60 meters) for an average of 58 seconds. The Common Eider reportedly reaches depths of 65 feet.
Factors Affecting Diving Performance
A duck’s diving performance is influenced by species differences, prey availability, and water conditions. Ducks are broadly categorized into “dabbling ducks” and “diving ducks,” based on their feeding strategies. Dabbling ducks primarily feed on the water’s surface or by tipping their bodies to reach shallow underwater vegetation, rarely fully submerging. Examples include Mallards and Wood Ducks, which may dive briefly to escape predators but typically stay submerged for only a few seconds.
In contrast, diving ducks are well-adapted for underwater foraging. Species like Canvasbacks, Scaup, and Goldeneyes pursue food like fish, mollusks, crustaceans, and submerged plants at greater depths. Diving efficiency is also influenced by prey availability; ducks may dive deeper and longer for food. Water conditions, including clarity, temperature, and depth, also affect how effectively ducks can dive and forage.