Photo by Tony Gamble.
We at Anole Annals are a little obsessed with what’s going on between anoles and those anole-wannabees, the day geckos, in Hawaii. Really, someone’s gotta’ study this. Here’s a photo kindly provided by Tony Gamble demonstrating beyond a shadow of a doubt that the two species coexist. Here’s Tony’s take on whether the species interact:
Photo by Tony Gamble
“I didn’t see too many interactions between geckos and anoles. I would see large male anoles walk around and display in places loaded with day geckos. The geckos would certainly get out of the way of the brutish anoles but I did not observe anoles actually chasing or attacking geckos. Both species seem to be far more concerned with intraspecific interactions (attached photo on left shows a male Anolis eyeing the female on the other side of the fence). In some places they co-occurred at incredibly high densities (see photo below the fold) and given the abundance of roaches and spiders food does not seem like its a limiting factor. In Kona, which is fairly dry, anoles tend to be found only in areas that are irrigated (e.g. gardens, hotels, strip malls). Day geckos are more abundant in those places but can be found almost everywhere – even away from developed areas. It is possible interspecific interactions are different on more mesic parts of the big island and on other islands where more area is open to anoles. This is certainly an experiment in progress – we just need to find some time to observe it.”
How many anoles can you find in this photo (by Tony Gamble)?
And here’s the story of one particular anole “the photo is from Kona on the big island. Anoles and day geckos everywhere. There was one male anole that would patrol the palm tree outside my hotel room every day. He would head bob and flash his dewlap all the way to the top – disappear for an hour or so in the leaves at the top of the tree – then make his way back down, displaying the whole way down (see attached). Trunk-crown ecomorph indeed!”
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Robert Powell
I’ve long thought this would be a terrific project and a great excuse to go somewhere fun, although I’ve also thought grant reviewers might shake their heads and say something like: “Sure, this guy wants to go to Hawaii and study lizards … right!” That said, both species coexist and are reasonably abundant, although maybe not to the extent seen in Tony’s photos, on Pandanus palms on the grounds of the Bishop Museum in Honolulu. Also, although I’ve not seen interspecific interactions, I’ve noticed at several locations that geckos are more abundant on Sansevieria stands, which anoles avoid (possibly because they have some issues with traction?).
Gordon
About ten years ago, I saw a green male anole flashing his dewlap on a large leaf. Out comes an equally large day gecko and the anole runs away. That was the first time I saw a day gecko in Hawaii. It looked like a turf war and the anole gave way to the gecko. Now I hardly ever see any green anoles, just brown ones and the day geckos.
Rich Glor
To what degree have the larger species of Phelsuma expanded across Hawaii? Are most anole/gecko interactions still likely to involve the smaller P. laticauda?
Robert Powell
I’ve only seen P. laticauda in proximity of anoles. I get the impression that the larger species of Phelsuma are largely restricted to a few small pockets. Add that to the fact that Hawaiian A. carolinensis get very large, the interactions to date are probably more one-sided than when anoles and larger species of Phelsuma interact.
I saw A. sagrei interact with P. grandis in the Florida Keys, and it was all “make way for the big green guy.”
Sean Giery
I’ve thought about this system a fair bit, so I guess I’ll weigh in.
Phelsuma grandis, P. laticauda, Anolis carolinensis and A. sagrei can all be found together in Honolulu (along with a suite of nocturnal geckos, and Jackson’s chameleons). However, my impression is that the larger-scale distribution of most of these species is rather spotty, especially P. grandis. There is a lot of diversity in the richly vegetated, urban neighborhoods like Manoa and Makiki, but outside of these urban areas you are unlikely to find Phelsuma, and in many cases even Anolis are scarce outside of the cities. It is, as R. Powell says, an obvious opportunity for study, but as with other introductions (such as S. Florida) it’s also a bit complex.
During my time in Honolulu, I’ve never seen P. laticauda and A. carolinensis interact (despite having several dozen of each living in and around my house and office. P. laticauda seem to prefer broad, vertically-oriented micro-habitats that anoles tend to avoid (the above photo depicts this rather well). Therefore a competition-driven effect between Anolis and Phelsuma a la Petren and Case (1998) study seems unlikely. However, a basic study of all species involved would be very informative (does this exist for Hawaii?).
That said, if strong selection is occurring, then an effect could be detectible. Museum collections could be a good resource here, now or in the future. I’d volunteer to do the work.
Mary True
I am going to pitch in my non-scientific 2 cents. When I first bought my home on the Hamakua Coast of the Big Island 4 years ago I had an abundance of what I call chameleons (green with pink throats which they expand in mate seeking behavior) and the creamy brown night geckos… no green day geckos.
There were green day geckos 1 & 1/2 blocks down the road at a smoothie shop. It was about a year before I saw a green gecko on my lanai. Things have really changed in the last 3 years. It appears to me that the green gecko has cannibalized both the brown gecko and the chameleons. Their numbers have declined drastically and I literally had 3 green geckos crawling on me while I had breakfast yesterday on my lanai. They appear to be more intelligent and have more personality, but I am very sad that they don’t seem to be coexisting very well with my other crawly friends who have almost disappeared.
Travis
Checking in from Maui. Sitting at our B&B lanai each morning and afternoon, I noticed that smaller anoles give a wider berth to larger anoles than a similar sized day gecko would. The largest anoles are bigger than all the day geckos, and similar is size to the largest night geckos. Anole display seemed to me to be as random as rooster crowing, but I imagine I’m just missing something.
Charli
I have a green anole & a day gecko in a terrarium together. They are best friends. I was wondering if I could breed the 2 of them
Linda
I have seen geckos eating another gecko twice since we have been here on the Big Island. Geckos are carnivores?
Jonathan Losos
Yes!