Colonizer extraordinaire A. sagrei has been known from the Hawaiian islands since 1980 and has become established on not only Oahu, where it first appeared, but also on Kauai and Maui. Now Mautz and Shaffer report in the December, 2011 issue of Herpetological Review that it has become established in several locations on the Big Island (Hawaii).
First detected in the lush plantings of several resorts, Mautz and Shaffer figured plant nurseries were probably the culprit for their spread, as they have been elsewhere. When they visited a local garden store, sure enough, the brown anoles were there in abundance.
Indeed, where the brown anoles were found, which was not everywhere, they clearly were well-established. At one site, two observers found 26 brownies in a 1 hour, 45 minute visit, whereas at another site in only 47 minutes, 62 adult and juvenile browns were seen.
Mautz and Shaffer conclude: “Given the current limited distribution of A. sagrei on Hawaii Island, we strongly recommend that immediate action be taken to eradicate it before it can spread further.” But I’d wager that it’s too late. Brown anoles breed like rabbits and are wilier than coyotes–I’d predict that nothing less than a scorched earth policy would be able to eradicate them.
Mautz and Shaffer’s article raises another interesting point about the Hawaiian herpetofauna.
While surveying brown anoles, the authors noted all other lizards observed, and in most cases that included a number of the beautiful gold dust day gecko, Phelsuma laticauda, introduced from Madagascar. In fact, several species of Phelsuma have been introduced into the Hawaiian islands and are quite abundant in some localities. And that, in turn, has set the stage for an ecological showdown of epic proportion, an intercontinental extravaganza pitting diurnal, arboreal, insectivorous champions of the new world, Anolis sagrei and Anolis carolinensis, versus their Indian Ocean döppelgangers, those adorable green anole wannabees, the day geckos.
They occupy the same niche! They eat the same insects! They’re about the same size! What will happen? Who’s a bigger, badder green (or brown) lizard? Which evolutionary radiation is tougher? Surely, most would predict that anoles, with their 400 species and 40 million years plus of evolution, would prevail against these Old World upstarts, but who knows? As far as I’m aware, no research has been conducted on this subject, though anecdotal reports suggest that the day geckos may have the upper hand in Oahu. Those of you in Hawaii, get out there and tell us what’s going down.
One final note. For those of you who are wondering, the junior author of this paper is, indeed, the Shaffer of salamander and turtle fame, who has now scaled the evolutionary ladder to its pinnacle. Welcome to the Anolis Club, Brad. Glad you finally realized that life’s too short not to study anoles.