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Hawaiian Monk Seal

Critically Endangered



1600 are estimated to remain


2.1 – 2.4 metres


140 to 270 kg


United States of America – Hawaii


The Hawaiian Monk Seal population was last estimated in 2016, with 1400 to 1600 animals in existence.

The Hawaiian Monk Seal has a relatively small distribution with the majority of animals being found on the Northwestern Hawaiian Islands.


The Hawaiin Monk Seal has a grey coat with a white belly. It is distinguished from the harbor seal by its slender physique. Being such a slender seal, it is much more agile for hunting its prey. The species is rather small for a seal and has a small, flat head with large black eyes. The species has 8 pairs of teeth, a short snout with the nostrils being on top of the snout. These nostrils will close when under water.

The hair of the Hawaiian Monk Seal is generally a dark grey on the dorsal side and a lighter silver ventrally and will change with years of exposure, with sea water and sun causing the colours to shift towards brown.

The species does not have external ears and cannot rotate its hind flippers under its body like other species of seals.

Quick Facts

Find Out More About the Hawaiian Monk Seal
  • Monk seal shed their hair and outer layer skin annually. During which the species spends most of its time on the beach
  • The species have a life expectancy of 25 to 30 years
  • The species mates in the water during breeding season which happens between December and August. Females bear one pup a year from the age of 4 with the baby taking around 9 months to develop
  • Pups are born on the beach and will be nursed by their mother for around 6 weeks. During this time span, the mother does not eat or leave the pup at all after which it will leave the animal on its own to go feed
  • Most of the time is spent hunting for food or basking in the sun
  • Fish – reef dwelling bony fish
  • Lobster
  • Octopus and Squid – this is the preferred prey for younger Hawaiian monk seals.
  • Eels

The majority of the Hawaiian Monk Seal is mostly found around the Northwestern Hawaiian Islands, but a small and slowly increasing population is being found around the main Hawaiian Islands. The species spends two-thirds of its time at sea, and is mostly spent in lagoons instead of deep ocean, but do often visit depths of up to 300 metres near reefs.

  • Tiger sharks and Galapagos sharks are natural predators of the Hawaiian Monk Seal
  • Reduction of habitat and change in predators and prey due to climate change and over fishing and erosion of the land masses the species uses
  • Low juvenile survival rates – due to starvation, marine debris and sharks. Most individuals of the species bare scars from shark attacks
  • Increasing male aggression during mating season
  • Injuries from marine debris and fishery issues
  • Low level of genetic variability. It has the lowest of all seal species. Intense hunting in the 19th century caused a population bottleneck in genetics. This causes the species to have difficulties adapting to changing environments
  • The species is susceptible to toxoplasmosis pathogen which is found from cat faeces which gets washed into the ocean. Other pathogens causes problems with the species
  • Population growth struggles due to avoiding human contact on beaches not allowing the species population to grow due to human presences on beaches

Conservation Efforts

National Oceanic and Atmospheric Administration (NOAA)

This organisation works to raise awareness of the species with fisherman and aids in improving habits of fisherman, maintaining monk seal habitats, population surveys and assisting research efforts.

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