Profile: Hawaiian Monk Seals
Key Facts about the Hawaiian Monk Seal:
  • The Hawaiian Monk Seal is one of the most endangered species in the world
  • They are endemic to the Hawaiian Islands and exist nowhere else in the world
  • Habitat covers 1,240 miles from the Northwest Hawaiian Islands to the main Hawaiian Islands
  • The Hawaiian name is 'Ilio-holo-i-ka-uaua, which translates to dog running in the rough seas
  • Monk Seals are the oldest species of seals on the planet
  • The Hawaiian Monk Seal is the official state mammal of Hawaii
  • Protected under the Endangered Species Act and the Marine Mammal Protection Act
Description
Life Expectancy: 25 - 30 years

Length: 5 - 7 feet

Weight: 400 - 600 pounds (females are slightly larger then males)

Appearance: Silver/Gray to Brown colored backs with lighter coloration on their undersides. The back of the seals may also become darker with age, particularly in males.
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Phocidae
Genus: Monachus
Species: Schauinslandi
Diet
Hawaiian Monk Seals are generalists feeders and will eat a variety of prey depending upon what is available in a given area. This may include a variety of fish species, squid, octopus, eels, crabs and lobsters.
  • Can consume between 3 - 8% of their body weight per day depending upon their age and maturity.
  • Primarily hunt outside the immediate shoreline areas in depths between 60 - 300 feet. However, they are capable of diving to depths of 1500 feet.
  • Prefer prey that is easy to catch unlike popular gamefish such as the ulua and papio.
  • Excess energy from prey is stored in the form of fat. This fat is essential to their long term survival as it provides needed nutrients when a seal fasts during nursing or molting.
Reproduction
  • Females reach sexual maturity between 5 and 6 years of age. It is unknown when Males reach sexual maturity.
  • Mating occurs in the water though it has rarely been observed by humans.
  • The majority of births occur in late March to early April however births have been recorded year round.
  • Roughly 65% of all female adults give birth each year.
  • Gestation is between 10 and 11 months with the Mom giving birth to one pup weight approximately 30 to 35  pounds.
  • The nursing period is between 5 and 7 weeks during which time the pup's weight can increase by as much as 5 to 8 pounds per day. Mothers do not eat during this time.
Top Threats
While the Hawaiian Monk Seal is one species, the primary threats the sub-populations face in the Northwest Hawaiian Islands and the Main Hawaiian Islands are quite different.

Northwest Hawaiian Islands Populations
  • Food Limitations
  • Shark Predation
  • Entanglements in Marine Debris
  • Habitat Loss

Main Hawaiian Islands Populations
  • Human Disturbance
  • Fishery Interactions
  • Human habituation
  • Disease
  • Intentional Killings
NOAA PDF Documents
Take Action
 
Did you know?
Isolated from their closest relative 15 million years ago, Hawaiian Monk Seals are considered a "living fossil" because of their distinct evolutionary lineage.
NOAA Hotlines
To report sightings:

Oahu: (808) 220-7802
Kauai: (808) 651-7668
Molokai: (808) 553-5555
Maui/Lanai: (808) 292-2372
Island of Hawaii-
East: (808) 756-5961
West: (808) 987-0765