'Ōhiki and hōkū original

Original 5.5"x7.25" illustration.

‘Ōhiki (Ocypode pallidula).

These crabs are native to Hawai’i and the Indo-Pacific. They are primarily active during the night, although it is not rare to see them in the day digging their burrows or scavenging for some snack along the shoreline. Like many creatures (including us), the activity level of ‘ōhiki are affected by the phases of the moon.

Ghost crabs can change their color to match their environment through color-producing cells called chromatophores, which are also found in squids and octopus. Unlike cephalopods, which can change color rapidly, ghost crabs change color over the course of one or more days. Being able to change color is how ‘ōhiki of the same species may look very different depending on the sand color—an ‘ōhiki on a black sand beach will look much different than one on a white sand beach. They can even look multicolored in sand that has a varied composition! On Hōlanikū (Kure atoll), where ‘ōhiki are incredibly abundant, it wasn’t uncommon to see lavender, bright red, and dark purple crabs, despite the sand being white. I’m not sure why that is.

“’Ōhiki” also means to probe or pick out, and “lua ‘ōhiki” (sand crab hole) was a term given to houses that were placed improperly and open on all sides.

Ghost crabs can be a good indicator species, signifying the health of their ecosystem; since they prefer less disturbed areas (i.e., not a lot of foot traffic, pollution, or development), they are more likely to occur on shores that see less human activity. Although they are small, ghost crabs have a mighty role in their ecosystems as recyclers and scavengers. In the first video, they can be seen eating an albatross chick that didn’t make it to fledging. In the Northwestern Hawaiian Islands bird carcasses can quickly litter the ground at certain times of the year, but ōhiki make sure they are quickly taken care of.