Brown Anoles on Hawaii and Battle of the Intercontinental Convergents

A brown anole from Lanai. Photo from,-Avian-Conflict-and-Lanai-Dragons-A-Photo-Diary

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.

The gold dust gecko in Hawaii. Photo from 2995054890_c987b2294c.jpg

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.

About Jonathan Losos

Professor and Curator of Herpetology at the Museum of Comparative Zoology at Harvard University. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.

29 thoughts on “Brown Anoles on Hawaii and Battle of the Intercontinental Convergents

  1. I’d agree with the notion that eradication is likely already an impossibility. Perhaps even more importantly, I doubt there will be the will to undertake such an operation (either financially, practically, or politically).

    It’s amazing it’s taken Shaffer so long to see the light.

  2. Anolis and Phelsuma certainly do hang out together in Hawaii. Both species seem so intent on beating up conspecifics though that most competition is likely indirect. Here’s a photo from Kona on the big island.

    1. I spent 30 minutes trying to get a similar shot of A. carolinensis and Phelsuma on a narrow palm trunk just north of Kona. They keep squirreling around and I never got a pic with both in frame.

  3. Of course, my real goal here is to convince the A-heads out there that the REAL, true pinnacle has a hard shell, a couple of funny joints in the neck, and lives 100 years or so. Soon, I expect Jonathan will be Dr. Turtle.

    I attach two photos of our brownies, on site, on the Big Island. Aloha.


  4. I’ve long thought about looking at interactions between Phelsuma and Anolis in Hawaii, but figured that someone evaluating a grant proposal to that effect would say something like: “Sure, this guy wants to study lizards in Hawaii… No way we’ll fund this boondoggle.”

    At one site in the Manoa Valley on Oahu where P. laticauda and A. carolinensis were apparently syntopic, the former dominated dense stands of Snake Plant (Sansevieria trifasciata), whereas the latter were found almost exclusively on rougher surfaces such as the bark of various trees and shrubs. However, at another site in Honolulu, the same two species were both equally abundant in stands of “Corn Plants” (Dracaena sp.).

    1. Very interesting. I think this would make a great study, but I can see your concerns. I remember once that a reviewer of a grant proposal to study Kenyan chameleons remarked that it was a boondoggle, since all the PI had to do was go to Florida to study them.

      1. Phelsuma standingi and P. grandis (both large day gecko species) bites hurt and can draw blood. Nothing like a large tokay gecko or Anolis equestris though, both of which rank equally high on my “bites to try and avoid but somehow never do” list.

  5. The brown anoles and Phelsuma laticauda may be able to sort things out between themselves as they expand to exploit Hawaii urban and suburban habitats. The brown anoles like the low life among lower tree trunks, ground, rock walls, and shrubs, while the Phelsuma tend to take the higher road on walls and trunks. They do overlap but have that partitioning tendancy. I believe, that P. laticauda, since they arrived at my house, have nearly completely displaced formerly highly abundant house geckos and mourning geckos (Lepidodactylus lugubris). The phelsumas come out at night under the lights, because that’s where the bugs are, and the other geckos are now nearly gone from these sites. Phelsuma success may be drought related as well. During the past year of relative drought on the Hilo side of the Big Island, the phelsumas have had the run of the place. The drought has ended, and after 2 weeks of nearly continuous cool (in the thermal sense) rainy weather, I see the poor dark complected phelsumas out in little pockets sheltered from the breeze trying to catch some rays filtered through the clouds. Normally rainy weather (125 inches/yr in Hilo) could be another tipping point in the habitat partitioning of new colonist lizards here.
    Brad and I will need a grant to go back to the Four Seasons Hualalai Resort and sort this all out in style.

  6. While visiting a nusery here on the big island, I was very surprised to find a VERY healthy population of A. Sagrei as I had not previously known to be present on this island. I saw maybe 50 or so specimens in varying stages if maturity in the 20 or so minutes I was there. I was also surprised to see a very low number of P. Laticauda which are usually in high abundance. I didn’t see more then 4 individuals the whole time and didn’t see any A. carolinensis. My money is between Sagrei and Laticauda based on the fact that where A. carolinensis used to be very abundant, they are now replaced by P. Laticuada. I don’t have much experience with A. Sagrei other then the few times I got to observe them in Oahu however. I am simply making a guess based on the sheer density of them I saw in such a
    small space.


  7. I first noticed the brown anoles at my mom’s house in Kaneohe. No green anoles were seen. I thought that was strange. I asked her about the skinnier, faster lizards. she mentioned that they seemed to have chased out all of the green ones.

    I, on the other hand, had green anoles running all over the place in my yard in Mililani. I think they look nicer. One day I saw a brown one. After about a year, I had no more green anoles. ALL GONE! I think the green ones are set for extinction on Oahu. Those brown anoles are quick and mean. I see them fight sometimes and it’s like watching the Tasmanian Devil on Looney Toons.

  8. I just noticed the first Phelsuma laticaudaI I’ve ever seen here at my house in Kaneohe. We used to have a lot of Anolis carolinensis around but they all but disappeared when Anolis sagrei found their way here a few years ago.

  9. Thank you for your most informative findings. I often wondered what happened to the A. carolinensis and those rare black salamanders in my yard in Kahalu’u, Oahu. Now, all I see is A. sagrei in my yard. I still have a few Hemidactylus frenatus in my home of which I was more familiar with growing up in Hawaii.

  10. Here is a photo of a “brown” anole on a red torch ginger on Kauai, after spotting a juvenile Phelsuma on the wall of the house.

  11. Here are some fun pics of the Phelsuma Day Geckos (I believe) from the Hilo Botanical Garden. Cute little buggers! wondering what are the negative ecological impacts of these and the anoles.

  12. I am visiting Maui (Kihei) for the first time since 1992. When I was here then and in 1990, there were geckos galore. I kept telling my kids about the geckos we would see. We are on day 4 and still no geckos (seen; perhaps heard, though), but A. sagrei galore.

    1. Finally saw some geckos last night up in the rafters of a community area of our resort (where the lights were turned on) and then near our door–again, near lights. Still not the same as seeing them all over the place like I did back in ’92.

  13. We have lived here in Kihei, Maui for 30 yrs, and hardly see gecko anymore. In the last 2 yrs the brown anole have taken over my flowers and yard (hundreds). I wish we could get rid of them because the match the concrete. if anyone know how let me know. When I come out of the house I have to watch so I don’t step on them. ( I already have in my bearfeet, its disgusting)

  14. Moanalua, Honolulu: At my house, the brown anoles and gold dust day geckos seem to be able to co-exist. No green anoles anymore. Although I did see a large green one at the park down the street not long ago. The brown anoles are winning the numbers game.

  15. Saw an Anolis carolinensis yesterday in the native hibiscus in our yard here in Palolo on Oahu for the first time in awhile, mostly Anolis sagrei otherwise.

  16. What is the situation of introduced reptiles in Hawaii? It seems most of them thrive in human-created or supported environments. Do any of them, besides L. lugubris, have spread in true wilderness? It would be interesting how they could evolve and sort themselves out in the future. Perhapse new species or at least varieties will arise some day?

  17. I haven’t seen a. carolinensis for years until yesterday at Helemano Plantation! A. sangrei have indeed taken over, and I notice they live in denser populations, too. The exception is my swimming pool area– the phelsuma laticauda (Gold Dust Day Gecko) pretty much rule the roost there, although there are a few bushes that the a. sangrei live in. I’m *this* close to convincing myself to buy some a. carolinensis and turn my apartment into a breeding ground in order to re-release them into the wild! My girlfriend is on board with the idea, too!

  18. I see dozens of brown anoles in my yard in Kailua. When I open my front door they come running out and stare at me, I usually mumble something to them and they dont move even when i walk toward them, i have saved many of them from my pool. Im not a nut but i wonder sometimes if the older ones might have some sort of facial recognition of me as they seem more curious than frightened, are they intelligent? I literally come face to face with them and they dont run away.

    1. Our place in Kaneohe is overrun with them. When I get the spade out and start turning the garden over they hover around and swoop in for the insects. Great fun to watch and feed.

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