During Seal Pupping Season, Why Might You See a Pup Alone Onshore?

A day at the beach is always a day well spent, but it’s even better spent when you catch a glimpse of a seal pup. You may be concerned if you see one alone, wondering if they’ve somehow been separated from their mothers or abandoned. That may tempt you to try to intervene. However, wildlife officials say that’s not a good idea. Here’s some background on seal pupping and why you find them alone onshore.


The Basics of Seal Pupping

Harbor seal pupping season begins in March and runs through early summer. On the west coast, the further north the seals are, the later the births come. Females give birth on tidal sandbars, rocky reefs, or pocket beaches and nurse for four to six weeks. During that time, mothers are typically with their pups, but that’s not always the case.

A Young Pup Alone Onshore

After pups are born, their mothers will sometimes leave them onshore to rest as they go forage for food in the water. They will likely return, but that may not be the case if there’s a commotion near their pup.

Diane Lambourn, a marine mammal biologist with the Washington State Department of Fish and Wildlife, says, “Any type of disturbance, harbor seal moms are very shy and wary, they do not like to be on land; they are uncomfortable on land if they perceive that there is a disturbance. They tend to go into the water and may end up leaving their pups behind.”


She adds that people and dogs near their pups appear to be a threat, and they won’t return as long as the threat remains.

One of the most important times to give these animals space is right after a birth, when bonding is taking place.

Lambourn explains, “It is really important for harbor seals and their babies to bond. If the mom and the pup cannot bond within that first half an hour, that is the time when we do see separation, because mom doesn’t know who that baby is.”

A Weaned Pup Onshore

Seals are born knowing how to swim, so they may go with their mothers on foraging trips. Once they are weaned from the milk that helps them grow from an average of 25 pounds at birth to up to 50 pounds, they begin foraging for themselves. At that point, a lone pup may actually be entirely on its own.

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Oregon State University marine mammal biologist Jim Rice says, “After suckling for about four weeks, weaned pups are abandoned by their mothers, left to fend for themselves. They will continue to come onto beaches periodically to rest as they grow and learn how to catch their own food.”

It’s best to give them their space at this point, as well, due to the challenging task of survival. Scientists say their best chance is at the beach where they belong.

In addition to rest, ‘hauling out’ onshore also helps them regulate their body temperatures. Because they’re smaller and have a thinner layer of blubber, they’ll get too cold if they’re in the water all the time.


The Point Reyes (California) National Seashore website explains, “When seals haul out, they are extremely vulnerable to human disturbance. Often they will react when humans come within 300 feet. Their reactions can be anything from a head alert — lifting their head — to flushing — retreating into the water. Harbor seals leave their haul-out sites when harassed by people, dogs, boats, aircraft or other human actions. Even a temporary disruption stresses the animal by cutting into its time to warm up, rest, and nurture young.”

So the next time you see a lone seal pup, even if you’re concerned about its wellbeing, it’s best to give it space and avoid intervening.

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