What we do know is that for as long as humans have been here, geckoes have lived among us. Early Hawaiians were aware of them, though they don’t seem to have distinguished among different species. The Hawaiian language has only one word for lizard: mo‘o.
Even though there were only seven species of lizard here before Western contact (the four geckoes and three skinks, also stowaways), Hawaiian legends are filled with them. These mythic mo‘o were not the harmless “house or rock lizards … or any of the little creatures with which we are familiar,” writes nineteenth-century Hawaiian historian Samuel Kamakau. Mo‘o, he says, are terrifying, dragonlike creatures up to twenty-five feet long. Unpredictable and capricious, mo‘o might aid or attack trespassers in their territories—usually streams, lakes, waterfalls and fishponds—and failure to propitiate the fickle spirit could prove fatal.
For some, mo‘o aren’t pure myth. Kamakau insists that “hundreds and thousands of people” had physically seen Mokuhinia, a mo‘o that lived on Maui. Muriel Seto, a Kailua resident who collected oral histories in the 1960s, wrote that some of Kailua’s küpuna (elders) reported seeing Hauwahine, the mo‘o of Kawainui wetland. Some Hawaiian families today claim the mo‘o as their ‘aumakua, or spirit guardian. For them the physical embodiment of the ‘aumakua—like the gecko—is to be protected. Harming one could have dire consequences: “Mai kolohe i ka mo‘o o lele i ka pali,” goes one proverb in Mary Kawena Pukui’s ‘Ölelo No‘eau. A warning, Pukui explains, not to bother lizards lest the mo‘o spirit drive you to leap to your death.
Maybe it’s just lucky that with all the trans-Pacific commerce moving through Hawai‘i after 1778, no new gecko species debarked. If they did, they didn’t survive. It wasn’t until 1951 that the new kid on the block, the common house gecko (Hemidactylus frenatus), was first reported in Kailua, O‘ahu. In the sixty years since, the house gecko has become the classic Hawai‘i gecko. Its body type (wedge-shaped head, meaty torso, curlicue tail) was Lum’s model for the Geckoes in Paradise sculptures, and it’s the gecko you’re most likely to see and hear these days. Frenatus probably hitched a ride to Hawai‘i on military equipment returning from the Pacific theater after WWII. With the larger human war ending, few paid attention to the smaller war just beginning.
What’s remarkable—and instructive—about the house gecko is how quickly it displaced the geckoes that were already here. This fierce and territorial insectivore is a widely distributed “tropicopolitan” species; as of 2008 it’s been cataloged in eighty-seven locations outside its native range. It’s also what Sean McKeown, author of A Field Guide to the Reptiles and Amphibians in the Hawaiian Islands, calls a “supertramp”: a generalist that prospers in a variety of different habitats. When supertramps move into a favorable area, they often spread rapidly, and Hawai‘i offered the house gecko a wide-open niche. Throughout the 1970s and 1980s, writes McKeown, mourning and stump-toed geckoes were the most common lizards around lights at night on Kaua‘i. That changed. Now the house gecko is by far the most abundant gecko in urban and suburban Kaua‘i as well as on all the main islands. It’s even managed to colonize barren Kaho‘olawe. In less than one human generation, the familiar geckoes old-timers had grown up with gradually declined as this sallow-skinned parvenu became the new lizard king.
Whenever a new species shows up in an island ecosystem, there’s reason for concern, but it’s difficult to say what effect geckoes have had on native species. The early geckoes “might have been a disaster for native insects,” says Kraus, “but if they were, it occurred over a thousand years ago, and we’ll never know about it.” And because the house gecko sticks mostly to areas the earlier geckoes have already colonized, says Kraus, its impact on native species is probably negligible. “But nobody’s looked,” he cautions, “and nobody’s likely to.”
So geckoes have mostly fallen through the cracks—ignored as neutral, welcomed as beneficial or even, as with the “day geckoes,” beloved for their beauty. Day geckoes have been here for only thirty-odd years. They’re spreading, and what impact they might eventually have, nobody knows.