foraging in deeper water outside of shallow lagoon reefs at sub-photic depths of or more. Hawaiian monk seals breed and haul-out on sand, corals, and volcanic rock; sandy beaches are more commonly used for pupping. Due to the immense distance separating the Hawaiian Islands from other land masses capable of supporting the Hawaiian monk seal, its habitat is limited to the Hawaiian Islands. Feeding Hawaiian monk seals mainly prey on reef dwelling bony fish, but they also prey on cephalopods, and crustaceans. Both juveniles and sub-adults prey more on smaller octopus species, such as Octopus leteus and O. hawaiiensis, nocturnal octopus species, and eels than the adult Hawaiian monk seals, while adult seals feed mostly on larger octopus species such as O. cyanea. Hawaiian monk seals have a broad and diverse diet due to foraging plasticity which allows them to be opportunistic predators that feed on a wide variety of available prey. Hawaiian monk seals can hold their breath for up to 20 minutes and dive more than ; however, they usually dive an average of 6 minutes to depths of less than to forage at the seafloor. Predators Tiger sharks, great white sharks and Galapagos sharks are the main predators of the Hawaiian monk seal. Behavior Reproduction Hawaiian monk seals mate in the water during their breeding season, which occurs between June and August. Females reach maturity at age four and give birth to one pup a year. The fetus takes nine months to develop, with birth occurring between March and June. Pups start around and are about long. Nursing The pups are born on beaches and nursed for about six weeks. The mother does not eat or leave the pup while nursing. After that time, the mother deserts the pup, leaving it on its own, and returns to the sea to forage for the first time since the pup's arrival. Status Most seals are found on the Northwestern Hawaiian Islands. The Hawaiian monk seal is endangered, although its cousin species, the Mediterranean monk seal (M. monachus), is even rarer, and the even more closely related Caribbean monk seal (N. tropicalis), last sighted in the 1950s, was officially declared extinct in June 2008. The total population of Hawaiian monk seals is in decline – the larger population that inhabits the northwest islands is declining while the smaller population on the main islands is increasing. In 2010, it was estimated