Fact Sheet
Hawaiian Monk Seal

Basic Facts About Hawaiian Monk Seals

Hawaiian monk seals are known as the "most primitive of living seals." They have streamlined bodies which make them good swimmer. Their front and back limbs are flipper-like – the front flippers, which have five digits, are smaller than the back flippers. The hind flippers cannot be turned forward, so to move on land, the seals must wiggle them. In the water, Hawaiian monk seals propel themselves by moving their hind flippers and using their front flippers as rudders. They are dark gray on their back side and silvery gray on their stomachs.

Hawaiian Monk Seal, Photo: U.S. Fish and Wildlife Service

© U.S. Fish and Wildlife Service

Diet

Hawaiian monk seals primarily eat fish, octopus, squid, and lobster.

Population

The current population of Hawaiian monk seals is currently around 1,000 individuals.

Range

The Hawaiian monk seal occurs only in the Central Pacific, in the mostly uninhabited northwestern Hawaiian Islands, with a small breeding population inhabiting the main Hawaiian Islands.

Behavior

Hawaiian monk seals inhabit reefs, shallow lagoons, open ocean and beaches. They commonly haul out on sandy beaches. Hawaiian monk seals do not have special physical adaptations to deal with the warm climate in which they live. Instead, they remain inactive during the heat of the day, finding a resting spot with shade or wet sand. They are solitary animals both on land and in the water. The Hawaiian monk seal evolved in an area without people or other land predators. Therefore, it did not learn to fear people and is easily approachable and disturbed.

Reproduction
Mating Season:
Between December and mid-August.
Gestation: Approximately 1 year.
Litter Size: 1 pup
Pups are about three feet long and weigh about 35 pounds when they are born. They stay with their mothers for 35 to 40 days while they nurse. During this time the mother gives the pup swimming lessons each day. While the pup is nursing, the mother fasts and may lose up to 200 pounds.

Threats

The Hawaiian monk seal uses sandy beaches for resting, molting, mating, and rearing young. Infant pups cannot swim, so they need to spend time on shore until they are big and strong enough to enter the ocean. The threat of sea level rising due to global climate change would reduce or even eliminate the available Hawaiian beaches on which these seals depend. Monk seals also depend on patterns of ocean productivity to support their foraging. In years when these patterns shift northward, away from the Islands, survival of young seals decline; something that might occur more frequently as the ocean warms.

Other threats to Hawaiian monk seals include human encroachment, shark predation, entanglement in fishing nets and longlines and marine debris, disease and commercial hunting for skins.

Reasons For Hope

In June 2008, Hawaiian Lieutenant Governer James Aiona declared the Hawaiian Monk Seal Hawaii's official state mammal, hoping to raise awareness regarding this rare and endangered creature, including increased funding for its protection.