The monk seals make their homes along the sandy beaches of Hawaii's coral reef. Every two years female monk seals reproduce young in limited numbers. When pups are born they average three feet long and weigh thirty pounds. Adult monk seals measure about seven feet in length and weigh between 400 and 600 pounds, with females often being larger than males. Female Hawaiian monk seals become sexually mature around six years of age. Pups are born about a year after mating takes place, usually between March and June. Mother monk seals are extremely sensitive to any disturbances at this time and have been known to abandon their pups when subjected to repeated visits by humans. Hawaiian monk seals have a maximum life expectancy of 30 years.

When attempting to capture food, monk seals have been recorded diving to depths of 400-600 feet to feed and can stay underwater for up to 20 minutes. The reason why monk seals are such expert divers is because they, like all other species of pinnipeds, have developed a very efficient means of using oxygen, allowing them to remain submerged for long periods of time without suffering brain damage or "the bends," two common consequences of oxygen deprivation. Adult seals have the ability to slow their heart rate to 4 to 15 beats per minute while diving, as compared to a rate of 55 to 120 beats per minute under normal surface conditions. Monk seals feed on bottom and reef fish, octopi, eels and spiny lobsters. Occasionally they will feed upon birds or even other seals.

Hawaiian monk seals are classified as pinnipeds and fall in the order of marine mammals including seals, sea lions and walruses. They have four swimming flippers that evolved from land mammals about 20 million years ago. In the water, their hind flippers propel them when swimming while their front flippers act as rudders or stabilizers. Monk seals have external ears.

Hawaiian monk seals seem to prefer a solitary life and rarely are found in groups.

The Hawaiian monk seal is Hawaii's only pinniped. It is a species that is considered endemic to the islands. The word endemic means that the species is unique to a region. That means it is found no where else and is believed to have evolved there. The monk seal is one of Hawaii's two endemic mammals. Hawaii's only other endemic mammal is the hoary bat.

Many other species found in Hawaii are considered indigenous, which means that they arrived in the islands under natural conditions such as by wind or by water, but can also be found in a number of different regions. Examples of animals indigenous to Hawaii are the humpback whale, the green sea turtle, and the Laysan albatross. Species that are either endemic or indigenous to a particular region are also considered native, or naturally occurring, to that region.

Many believe monk seals got their name from their monk-like preference for solitude. Others think that the loose skin around the seals' neck resembles the hood of a monk's robe. Ancient Hawaiians apparently thought neither and named the seal Ilio-holo-i-ka-uaua, which means "dog that runs in rough waters," referring back to their ancestral history. Monk seals are also sometimes referred to as "living fossils" because as the oldest living members of the pinniped order they have remained virtually unchanged for 15 million years.

Hawaiian monk seals are genetically tame and easily approached by humans.

In recent years, commercial fishing has been promoted around the northwestern Hawaiian Islands. Entanglement of monk seals in fishing nets and lines have been reported to have occurred somewhat frequently. Some researchers claim that because monk seals are curious and playful by nature that they may be "attracted" to the fishing gear and unfortunately become entangled in the process.

Shark attack is thought to be a major cause of death for Hawaiian monk seals. Ciguatera, a disease which results from ingesting fish which have a high concentration of naturally occurring toxin stored in their flesh has claimed the lives of many Hawaiian monk seals.

If you come across monk seals in the course of your activities it is recommended that you abide by the following:Do not approach monk seals while on land or in the water. They may approach swimmers, divers or vessels out of curiosity, but in no instance should you approach them. This may be considered a form of harassment.When it is necessary to pass by a monk seal that has hauled itself on to a beach, it is recommended that you remain a minimum distance of 100 feet away from the seal, so as not to disturb them. Do your best to avoid female monk seals with pups, and never come between a mother and a pup. Report sightings of injured or sick seals or of harassment by others to the National Marine Fisheries Service in Honolulu at your earliest convenience. The seals will thank you! The number there is (808)955-8831.