Seals are fascinating marine mammals that navigate both aquatic and terrestrial environments. While they are well-adapted for life in the ocean, these animals regularly spend time out of the water. This dual existence often prompts curiosity about how long seals can remain on land.
Why Seals Come Ashore
Seals come ashore, a behavior known as hauling out, for several biological reasons. They frequently seek land or ice to rest and conserve energy after foraging in the water. Hauling out is also important for thermoregulation, as seals can warm themselves in the sun or cool down by seeking shade or entering the water.
Land is also important for reproduction, as seals give birth and nurse their young there. Seals also undergo an annual molting process on land, shedding their old fur to grow a new coat. Hauling out provides a refuge from aquatic predators such as orcas and large sharks.
How Seals Survive on Land
Seals possess several adaptations for survival on land. A thick layer of blubber provides insulation against cold temperatures and serves as an energy reserve. This blubber also aids in heat retention.
Their circulatory system is highly efficient, adjusting blood flow to the skin and extremities to regulate body temperature on land. When hauled out, seals can dilate blood vessels near the skin to release heat or constrict them to conserve warmth. Seals also exhibit a higher metabolic rate and may huddle in groups to conserve warmth.
Factors Affecting Time Ashore
The duration a seal can stay out of water depends on several factors. Species play a role; for instance, harbor seals regularly spend about half their time on land and can rest for hours, with pups potentially staying ashore for up to 48 hours while their mothers forage. In contrast, elephant seals, known for their deep dives, spend the majority of their lives in the ocean but may remain on land for up to two months for molting or for males to defend breeding territories during the breeding season.
The purpose of hauling out is another factor; short rests might last a few hours, while molting can keep a seal on land for days to several weeks. Pupping and nursing periods can extend a mother and pup’s time ashore for weeks to a few months. A seal’s age and health also influence this duration, as young pups often spend more time on land, and sick or injured seals may haul out to rest and conserve energy. Environmental conditions like temperature, wind, and the presence of ice can affect how long seals remain on land. Human disturbance, through vessel traffic or direct approach, can also reduce the time seals spend ashore.
Dangers of Extended Land Stays
While seals are adapted for terrestrial periods, extended stays out of water pose risks. Dehydration can occur as seals lack access to fresh water. Overheating is another concern if seals cannot regulate their body temperature or find shade.
On land, seals are more vulnerable to terrestrial predators, particularly young pups. Human interaction presents a danger; approaching seals too closely can cause stress, interrupt resting or molting processes, and lead to exhaustion. Disturbances can also result in mother seals abandoning their pups, which reduces their chances of survival. It is important to maintain a significant distance from seals and report any concerns about a seal’s well-being to local wildlife authorities.