|Story by Janice Crowl
Photos by Elyse Butler
Mist blows over the peaks of the Honouliuli reserve, turning the path along the cliffs to mud. University of Hawai‘i professor Michael Hadfield, a spry and sure-footed 73-year-old veteran biologist, zips up the treacherous trail through native rainforest. He’s searching for an isolated population of critically endangered Achatinella tree snails here at 1,900 feet in the Wai‘anae range. This area, closed to the public, is one of the few remaining habitats where these jewel-like creatures still cling to life.
Hadfield inspects the undersides of the leaves of a short ‘ohi‘a tree where the nocturnal snails hide during the day.
“Here’s one,” he says. “It’s a beaut.” The shell is a creamy white conical spiral about as long as the tip of your pinkie. Called kahuli (to change or overturn) in Hawaiian, it perches on an intact leaf—no chewed holes. That’s because these snails don’t eat plants; they feed on mold growing on the leaves.
Dangling from a strip of surveyor’s tape affixed to a nearby ‘ohi‘a, five more snails huddle like a bunch of pointy berries. Hadfield notes other evidence of human intervention: rat bait stations placed among the trees and along the fence line.
The snails at this location are all Achatinella mustelina, a species found only in the Wai‘anae range. Yet they’re as diverse as a litter of poi dogs. Achatinella shells are colorful: pure white to pure black, greens, yellows and browns. Most have horizontal stripes. Hadfield examines a shell with lines that also run vertically.
“We call these plaids,” he says.