Hawaiian Monk Seal

Overview

The Hawaiian monk seal (Neomonachus schauinslandi) is an endangered earless seal endemic to the Hawaiian Archipelago. Known in Hawaiian as ‘īlio-holo-i-ka-uaua (“dog that runs in rough water”), it is one of the most endangered marine mammals in the world and the only seal native to Hawaii.

Distribution & habitat

These seals are found throughout the Hawaiian Islands, with the majority of the population residing in the remote Northwestern Hawaiian Islands and a smaller, growing subpopulation in the Main Hawaiian Islands. They utilize both terrestrial and marine environments, relying on sandy beaches for resting, molting, and nursing, while foraging in surrounding coral reefs and deeper offshore waters.

Appearance

Adults possess a robust, fusiform body with a relatively small, flat head and broad muzzle. Their coat color varies significantly; following an annual "catastrophic" molt, they appear silvery-gray to slate, fading to brownish or yellowish tones over time. Pups are born with a black, woolly coat called lanugo. Females are generally slightly larger than males, and individuals may develop scars or pale, irregular birthmarks over their lifetime.

Biology & behavior

Unlike many other phocids, Hawaiian monk seals are largely solitary and exhibit an asynchronous breeding cycle, meaning they can give birth year-round. They are non-migratory and show high site fidelity to their preferred beaches. While they spend much of their time at sea, they are frequently observed hauling out on shore to rest.

Feeding

As generalist predators, they forage primarily at night. Their diet consists of a variety of prey, including reef fishes, eels, and cephalopods, which they hunt in shallow-water reefs and deeper offshore slopes.