Moose are large ungulates inhabiting northern North America, Europe, and Asia. As the largest deer family members, they stand over six feet tall at the shoulder and weigh over a thousand pounds. These animals are known for their connection to water, often seen wading or swimming in lakes and ponds. Their affinity for aquatic environments is important for survival in northern landscapes.
Underwater Endurance
Moose can hold their breath underwater, typically for 30 to 60 seconds. Adults can extend this time, with some individuals remaining submerged for up to 90 seconds. Calves also demonstrate underwater capabilities, often for 30 to 60 seconds. Though they can endure longer periods, moose commonly submerge for shorter durations, primarily for foraging.
Aquatic Behavior
Moose engage in underwater activities for several reasons. A primary motivation is to forage for aquatic vegetation, such as water lilies, pondweed, bladderwort, sedges, and horsetails, which are rich in nutrients like sodium, calcium, and protein. These plants offer minerals often scarce in terrestrial diets. Water also serves as a refuge from predators like wolves and bears, as moose can outswim many land-based threats.
Additionally, during warmer months, submerging helps moose escape biting insects and regulate body temperature. They can submerge their heads or entire bodies, sometimes walking along the bottom of shallow water bodies to access food.
Specialized Adaptations
Moose have evolved adaptations enabling their underwater capabilities. They possess large lungs, allowing them to take in and store oxygen before submerging. Their specialized nostrils feature valve-like structures that close tightly when submerged, preventing water from entering their respiratory system. This closing mechanism is often activated by the pressure difference between water and air.
Their long, strong legs are useful for navigating challenging terrain on land and help them walk on lake bottoms or propel themselves efficiently through water. The dense fur of a moose, with its hollow hairs, traps air, providing buoyancy and insulation in cold water.
Furthermore, moose can slow their heart rate during dives, a physiological response known as bradycardia, which conserves oxygen and extends their underwater time. Their prehensile upper lip and specialized mouth anatomy are also adapted for grasping and tearing aquatic plants while submerged.