Ducks exhibit a remarkable ability to navigate and forage beneath the water’s surface. Their proficiency in diving and holding their breath allows them to access food sources and evade threats. This underwater capability highlights specialized adaptations that enable their aquatic lifestyles.
Average and Maximum Dive Times
The duration a duck can remain submerged varies significantly depending on the species. Most diving ducks typically stay underwater for 10 to 30 seconds during a single dive. Some species, particularly sea ducks, can remain submerged for a minute or more.
For example, a white-winged scoter was observed to average 58 seconds underwater during consecutive dives. Exceptional cases have documented some diving ducks, like the Long-tailed Duck, staying underwater for nearly 4 minutes (230 seconds). In contrast, dabbling ducks, such as Mallards, rarely dive for long periods, typically only submerging for a few seconds, often around 5 seconds, primarily to escape predators.
Dabbling Ducks Versus Diving Ducks
Ducks are broadly categorized into dabbling ducks and diving ducks, based on their distinct feeding behaviors and physical characteristics. Dabbling ducks primarily feed on the surface of the water or in shallow areas by “tipping up,” submerging their heads and necks while their tails remain visible. Their legs are positioned closer to the middle of their bodies, which facilitates walking on land and allows for an easier, more direct takeoff into flight from the water’s surface.
Diving ducks, conversely, submerge their entire bodies to forage for food in deeper waters, propelling themselves underwater with powerful, webbed feet positioned further back on their bodies. This rearward leg placement makes them highly efficient swimmers but can result in a more awkward gait on land. Unlike dabblers, diving ducks often require a running start across the water’s surface to gain momentum for flight due to their smaller wing size relative to their body weight. Their bodies are typically more compact and streamlined, which reduces drag and enhances their agility underwater.
The Science Behind Underwater Dives
Ducks possess several physiological adaptations for underwater dives. Before diving, many species compress their feathers tightly against their bodies, expelling trapped air to reduce buoyancy and make submerging easier. Once submerged, diving ducks primarily use their large, webbed feet for propulsion, though some may also use their wings for additional movement, particularly when pursuing agile prey.
A physiological response during a dive is bradycardia, a slowing of the heart rate, which helps conserve oxygen. Blood flow is strategically redirected, prioritizing oxygen delivery to organs such as the brain and heart, while reducing supply to less sensitive tissues and skeletal muscles. Ducks also have enhanced oxygen storage capacity in their blood, due to higher hemoglobin concentrations, and in their muscles, through elevated myoglobin levels. These internal oxygen reserves permit them to sustain aerobic metabolism underwater for extended periods.
Reasons Ducks Dive
Ducks dive for several reasons, with foraging being a primary motivation. Diving ducks actively seek out aquatic plants, seeds, mollusks, insects, and small fish found at the bottom of bodies of water. Their specialized bills and feeding strategies allow them to filter or grasp various food items from the substrate. For instance, Ruddy Ducks dive to the bottom of shallow pools to strain mud for invertebrates and plant matter.
Another reason for diving is to escape predators. By quickly submerging, ducks can evade aerial threats like raptors or terrestrial predators near the water’s edge. While less common, some dives may also be associated with social interactions or playful behavior. These underwater excursions are integral to their survival in their aquatic habitats.