Seals are marine mammals adapted to ocean life. A common sight along many coastlines is a seal resting on the shore, a behavior known as hauling out. This natural occurrence often prompts questions from observers who might mistakenly believe the animal is stranded or in distress. Hauling out is a normal and frequent part of a seal’s biology, serving several purposes essential for their survival and well-being.
Essential Needs: Rest and Regulation
Seals, as semi-aquatic animals, must spend time on land to fulfill basic physiological requirements challenging to meet in the water. One reason for hauling out is to obtain undisturbed rest and sleep. On land, seals can achieve deeper states of rest, free from the constant motion of waves and the vigilance required to avoid marine predators. This allows them to conserve energy, which is important for their aquatic lifestyle.
Land also plays a significant role in a seal’s thermoregulation. After prolonged periods in cold ocean waters, seals use the warmth of the sun on land to elevate their body temperature. Conversely, if too warm, they might seek shade or return to the water to cool down. Some seals even adopt a “banana” pose, lifting both their head and tail, to regulate temperature by exposing more surface area to the air or minimizing contact with a hot surface. This ability to exchange heat with their environment while hauled out is an important adaptation for their survival.
Life Cycle Events: Molting and Reproduction
Biological events compel seals to spend extended periods on land, supporting important phases of their life cycle. Molting, the annual shedding of old fur and skin, is one such event. This can be an energy-intensive period, and remaining on land helps them conserve body heat that would otherwise be lost to colder water. For some species, molting can last for several weeks, during which they may not enter the water to feed.
Reproduction is another reason for seals to haul out, particularly for pupping and nursing their young. Many seal species choose stable terrestrial environments to give birth. This provides a safe platform for the mother to bond with her pup and nurse it without the challenges of strong currents or marine predators. Pups are born with a soft coat that offers limited insulation for immediate entry into cold water, making land or ice important for their initial development. Mother seals remain with their pups for weeks, providing nutrient-rich milk that allows the pups to rapidly gain weight and develop a thick blubber layer for insulation.
Seeking Safety: Avoiding Marine Threats
While seals are agile in the water, hauling out onto land also serves as a strategy to avoid marine predators. The ocean, despite being their primary habitat, harbors threats. By moving onto the shore, seals temporarily escape these aquatic dangers, finding a sanctuary where their predators cannot follow. This highlights how land offers a temporary refuge from aquatic perils.
When Something is Wrong: Signs of Distress
While most seals on shore are engaged in normal behaviors, there are instances when a seal’s presence on land indicates a problem. An injured, sick, or entangled seal may come ashore because it is weak or unable to forage effectively. Indicators of distress can include visible injuries, labored breathing, a very thin appearance, or unusual behaviors. A seal that appears lethargic, unresponsive to its surroundings, or exhibits repetitive, unnatural movements might also need assistance.
If an observer encounters a seal on the beach that appears to be in distress, remember that human intervention can cause more harm than good. Approaching, feeding, or attempting to move the animal can stress it further, potentially leading to aggressive behavior from the seal or habituation to humans, which can endanger both the animal and people. The appropriate action is to observe the animal from a significant distance and immediately contact local wildlife authorities or a marine mammal stranding network. These organizations have trained professionals who can assess the situation safely and determine the best course of action for the animal’s welfare.