Potted Plants And Invasive Lizards: A Case Study

Could a lizard stowaway on a succulent?

We hear a lot about invasive anoles–A. sagrei and others–showing up all over the place: Singapore, Taiwan, you  name it. But how do they get there? I was recently reminded of an article by Gad Perry and colleagues in the journal Iguana (now Reptiles and Amphibians: Conservation and Natural History–a quarterly journal available online and worth a look). Perry et al. examined a barge delivering a large number of potted plants to the small island of Guana in the British Virgin Islands. The plants came initially from Florida, but had been sitting in a nursery on a nearby island for at least ten days. What would they contain?

To find out, the investigators laboriously inspected the plants, all 220+ of them, one by one. And sure enough, there were stowaways: six juvenile Puerto Rican crested anoles (A. cristatellus); a dwarf gecko, Sphaerodactylus macrolepis; also, an immature spider, three snails and nests of the red fire ant. In addition, the barge carrying the cargo contained two other lizards, Ameiva exsul.

And remember, this is one just one shipment. Now, in this case, all of the lizards were natives, as were most of the invertebrates. But imagine all of the plants being shipped out from Florida, containing brown anoles, Cuban treefrogs, and who knows what else? My prediction: it’s just a matter of time before brown anoles are everywhere in the urban tropical world.

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.

12 thoughts on “Potted Plants And Invasive Lizards: A Case Study

  1. Do not ignore the possibility of eggs being laid in potted plants — it has happened in some of mine that are outdoors!

  2. Several years ago during a symposium on introduced species at the joint meeting in Tampa, a number of speakers mentioned the likelihood of a pan-tropical herpetofauna that included Anolis sagrei, Ramphotyphlops braminus, and Osteopilus septentrionalis. Other species were implicated from time to time, but the big three were on pretty much everyone’s list.

  3. Hi Jonathon,
    That is a great observation. In most locations in south Florida the topsoil is scarcely a couple of inches deep with limestone or compacted marl directly beneath it. In my own yard the well aerated soil that I use for my potted plants usually contains an abundance of Anolis eggs during the warm months. I would venture to say that they prefer laying in the pots because the soil is relatively loose, and remains moist but never waterlogged. With the number of large tropical nurseries we have down here I would not be surprised if potted plants are the number one vector for the spread of Anolis throughout the state and several tropical/sub-tropical countries. Even if the plants are sprayed, the eggs probably remain safe underground and hatch out days or weeks later.

  4. I remember taking this exhausting 24+hr boat ride to Jampea Island in Indonesia from Selayer (and back). The boat was stuffed with cargo – coconuts, cashews, gas, motorcycles, a water buffalo, and people. There were dozens of potted plants on board as well – the non-herpetologist passengers didn’t seem to want to leave home without their favorite decorations.

    Take a second and try to find Jampea. It’s only a matter of time before anoles are there as well.

  5. I read with interest Robert Powell’ s indirect response to my recent sighting of A. sagrei in Grenada, the opposite end of the Caribbean from its source. While their lumber-yard theory is both interesting and feasible (Sagrei coming-in with packaged lumber from Florida) my sighting was from the backyard of the Guest House just across the road from Port Louis, the largest and most cosmopolitan marina for yachts which peruse the Caribbean. Indonesian natives may not be the only passengers who travel with miscellaneous cargo especially in countries where customs deparments are known to be selective or generally lax at best.

    1. In addition to Grenada, Anolis sagrei is well established on St. Vincent and is present on some of the Grenadines. The St. Vincent distribution suggests that the vector was building materials, but yachts might be implicated in the Grenadines. A recently established population on St. Maarten currently is restricted to the immediate area of the cruise ship harbor, which is still another means of these highly opportunistic lizards moving to places where they’re not native. A couple of years ago, I was asked to identify lizard remains found in sticky traps on a cruise ship. You guessed it, it was sagrei.

  6. Quite some of the Anolis I have kept/keep in vivaria or have been able to make pictures of, were found on tropical plants imported in the Netherlands.. That is ‘agave’ sticks from Costa Rica and Heliconia-plants and flowers from Colombia.. Not to mention the snakes an frogs that came in that way. I know a guy who worked at the dept. of plant health and had to check freshly imported plants for pests and such. People knew he liked those lizards and saved them for him… That way Anolis limifrons, biporcatus, cupreus polylepis aquaticus and lemurinus were imported here.
    If the not too voluminous route of live plants from those origins to the Netherlands, brings in such a species richness, I wonder if the ‘intertropical plant trade’ has’t had more species traveling then the three mentioned.
    Another point.. sometimes, a species which barely manages to survive on it’s own turf, can be almost weedy on another’s. ( I might mention Boiga irregularis here.. which manages quite well to survive on its own turf, but well.. is a pest elsewhere) I wonder if there are any examples of ‘displaced Anoles’ which are much more common on (for them ) foreign territory then they are ‘at home’.
    Has there been small colonies of exotic anoles around tropical plant traders in f.i. Florida and such/

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