Physical Description of the Hawaiian Monk Seal

  • Adult monk seals are about 6-7 feet in length and weigh about 350-500 pounds.
  • These animal can live to be 30-35 years of age but few seals live this long in the wild.
  • Both male and female monk seals are similar in body length.
  • Monk seal pups are black, while adults are dark gray to brown on their back and light gray to yellowish brown on their belly.
  • Monk seals shed the top layer of their skin and fur about once a year. This is called a “catastrophic molt.”
  • When seals spend a long time at sea foraging, they can grow algae on their fur. Seals that look green usually haven’t molted recently and may be getting ready to shed into a silvery, new coat.

“When one tugs at a single thing in nature, he finds it attached to the rest of the world.”
– John Muir (Author, naturalist, 1838-1914)

Read NOAA’s new Hawaiian monk seal natural history brochure.