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The enormous liolaemine radiation: paradoxical herbivory, viviparity, evolutionary cul-de-sacs and the impending mass extinction


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A small liolaemine lizard, encountered in Rio. Liolaemus lutzae, I presume? UPDATE: perhaps not! See update at bottom of article. Photo by Darren Naish

Did I mention that I spent time in Rio de Janeiro recently? Ha ha, kidding. While there I didn’t just look at birds and pterosaurs: I also pursued lizards when I could. Rio is home to a special, unique iguanian: Lutz’s tree iguana Liolaemus lutzae, an omnivorous, burrow-dwelling, beach-living liolaemine endemic to the Brazilian coast. Liolaemines (or liolaemids) are one of many iguanian groups classically regarded as a iguanid ‘subfamily’ and currently treated in different ways by different authors. Most recently, Pyron et al. (2013) treated all ‘iguanid’ clades as ‘families’ and found Liolaemidae to be the sister-group to a leiosaurid + oplurid clade

While looking for animals in the gardens of the Museu Nacional, I encountered a small liolaemine (estimated length = c. 50 mm SVL, c. 110 mm in total). I actually found the lizard thanks to the predatory efforts of a cat, which I saw making a quick grab for the lizard, causing it to take refuge in a crevice on a tree. My initial hypothesis was that this might be a Lutz’s tree iguana (my first-ever viewing of this distinctive species) and, having looked at photos online, I think that this is what it is. Please say if you know better.

Liolaemines have been covered on Tet Zoo before (on ver 2, back in February 2008) so now is a good time to recycle (and update) that text. Here it is…

My brilliant former pet, Ermentrude the liolaemine. He was most likely a member of the Chilean species Liolaemus nigroviridis. Photo by Darren Naish.

Liolaemus is a pretty interesting taxon (hey: just like all the others!). Occurring in South America from the Pacific to Atlantic coasts, and from Peru to Tierra del Fuego, its diversification appears to have occurred in the Andean and/or Patagonian highlands (Schulte et al. 2000). It’s a huge group, containing over 220 named species and with some studies hinting at the possibility of a futher 200 or so still awaiting publication. Indeed some herpetologists think that the Liolaemus radiation will eventually exceed the Anolis (sensu lato!) one in terms of number of species.

Phymaturus verdugo, an Argentinean liolaemid named in 2003. You can see why these lizards are sometimes called Alpine (or Chilean) chuckwallas. Photo by Gdebandi, licensed under Creative Commons Attribution 3.0 Unported license.

Unlike a few other iguanian clades (like the Australian dragons and anoles), diversification within liolaemines has apparently been slow and steady, rather than short and rapid (Harmon et al. 2003). While mostly inhabiting high altitudes, Liolaemus species dominate the scrubland lizard faunas of southern South America and in Chile it is typical to find four species partitioning the same habitat. Several species inhabit beaches, including L. lutzae. It is omnivorous, if not predominantly herbivorous as an adult (Rocha 1989, 1999), and has been very much affected by human development of its habitat. Some species inhabit places with strongly seasonal climates and can cope with very cold winters, and indeed L. magellanicus of Tierra del Fuego is the most southerly occurring lizard in the world. [Adjacent image of a Phymaturus species by Gdebandi.]

The viviparity cul-de-sac and… bad news for cool-adapted liolaemines?

Viviparity is present in about 55% of all known Liolaemus species, occurring in those high-altitude and/or high latitude taxa that have larger bodies (Cei et al. 2003, Pincheira-Donoso et al. 2013). It’s generally thought that viviparity is advantageous for cool-climate lizards because the mother’s thermoregulatory behaviour allows successful embryonic development in habitats frequently too cool for the successful incubation of shelled eggs. Conversely, viviparity is disadvantageous in warm climates since a female burdened with heavy embryos is relatively poor at running and more vulnerable to predation, and also slower at producing litters (Shine 2005). This doesn’t mean that all warm-climate lizards must be oviparous and all cool-climate ones viviparous, of course: exceptions abound.

Cyan tree iguana (Liolaemus cyanogaster) of Chile, one of many viviparous liolaemine species; photo by jjsaez, licensed under Creative Commons Attribution-Share Alike 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license.

The evolution of reproductive traits in Liolaemus has just been investigated by Pincheira-Donoso et al. (2013). They collected data from 153 species within the group (wow, that’s a lot of fieldwork; it clearly involved looking at thousands of specimens) and concluded that the evolution of viviparity is, indeed, strongly associated with the invasion of cool regions. However, their phylogenetic work led them to argue that these lizards cannot switch from viviparity back to oviparity: there are a few places in squamate phylogeny where such a transition might have occurred, but general thinking is that it’s essentially irreversible (Lee & Shine 1998).

Have you seen Pyron et al.'s (2013) ENORMOUS phylogenetic analysis of Squamata? 4161 species, representing all 'families' and 'subfamilies' (and it's open access: check it out). Here's the section of their iguanian tree that includes Liolaemidae - many, many Liolaemus species are included.

Given climate change, what does the future hold in store for these lizards? Pincheira-Donoso et al. (2013) suggest that a warming South America will encourage the invasion of higher elevations and higher latitudes by oviparous liolaemine lineages. Meanwhile, the many viviparous species will – if their evolution of viviparity truly is irreversible (in which case they’ve found themselves in an “evolutionary cul-de-sac”) – be increasingly restricted in range. Eventually, they’ll be competing directly with oviparous ones that will be competitively advantaged in a warmer climate (for the reasons discussed above). What then? Will there be a mass extinction of viviparous, cool-adapted liolaemines? “[T]hese predicted extinctions of viviparous species need not simply reduce Liolaemus diversity. We expect the genus to experience species turnovers in historically cold climates, where invasions by oviparous species (and extinction of viviparous [ones]) might drive new speciation events, resulting in new forms of high-latitude and high elevation Liolaemus fauna” (Pincheira-Donoso et al. 2013, p. 865).

Incidentally, at least one Liolaemus species is parthenogenetic, meaning that this trait has evolved in iguanians as well as in most other squamate lineages. Parthenogenesis has also been reported in Phymaturus, the sister-group to Liolaemus, but in that case it’s only known to have occurred in captivity (Chiszar et al. 1999).

One subject which has been discussed quite a lot in lizards concerns which correlations, if any, occur between morphology and mode of life, with some studies on some groups finding no obvious correlations at all. Indeed some workers have reported exactly this for Liolaemus (Jaksic et al. 1980). Schulte et al. (2004) did further work of this sort on Liolaemus and found that different species had different escape strategies, and it was these escape strategies that tied to morphological differences.

Paradoxical herbivory

Orange-bellied lizard (Liolaemus pictus) of Argentina and Chile in its montane home. Is the montane liolaemine fauna set to change dramatically in future decades? It would seem so. Image by Nsimean, licensed under Creative Commons Attribution-Share Alike 3.0 Unported license.

Within the liolaemid radiation, the members of Ctenoblepharys are insectivorous, the species included within Phymaturus are entirely herbivorous while the largest clade within the group – Liolaemus – includes insectivores, omnivores and herbivores. The widespread herbivory present within Liolaemus is not well known and, indeed, it’s repeatedly been missed or ignored in reviews of reptilian herbivory. Espinoza et al. (2004) drew attention to the fact that, contrary to predictions made on the basis of other herbivorous lizards (most of which are large, live in warm places and maintain high body temperatures), herbivory had repeatedly evolved at small body size and in cool-climate Liolaemus species. In fact, herbivory has probably evolved more times within Liolaemus than it has within any other squamate group, and about 66 times more rapidly than it has in non-liolaemid squamates (Espinoza et al. 2004, p. 16823).

It’s obvious that there’s a lot of interesting stuff to say about these lizards. New species are discovered on a regular basis, mostly due to surveying work in previously unexplored regions: not because of rampant splitting or the documentation of morphologically similar cryptic species. Ongoing work and the studies cited here mean that we’re sure to see liolaemines being appreciated  a lot more in coming decades – this is a major squamate radiation, the history and future of which need to become better appreciated and better understood.

For previous Tet Zoo articles on iguanians, see…

UPDATE: Thanks to Jonathan Losos for pimping this article at the fantastic Anole Annals. As revealed in the comments there by Roberto Langstroth, the animal that I’ve identified here as a possible Liolaemus lutzae is no such thing, but is in fact a member of Tropidurus. Hey, I did say above (second paragraph) that I was unsure of my identification! What is Tropidurus? It’s not a liolaemine but a member of another iguanian lineage, so I guess I’ll have to elaborate at some point.

Refs – -

Cei, J. M., Videla, F. & Vicente, L. 2003. From oviparity to viviparity: a preliminary note on the morphometric differentiation between oviparous and viviparous species assigned to the genus Liolaemus (Reptilia, Squamata, Liolaemidae). Journal of Zoological Systematics & Evolutionary Research 41, 152-156.

Chiszar, D., Gingery, T., Gingery, B., Smith, H. M. 1999. Phymaturus patagonicus (Argentine chuckwalla). Facultative parthenogenesis. Herpetological Review 30, 98.

Espinoza, R. E., Wiens, J. J. & Tracy, C. R. 2004. Recurrent evolution of herbivory in small, cold-climate lizards: breaking the ecophysiological rules of reptilian herbivory. Proceedings of the National Academy of Sciences 101, 16819-16824.

Harmon, L. J., Schulte, J. A., Larson, A. & Losos, J. B. 2003. Tempo and mode of evolutionary radiation in iguanian lizards. Science 301, 961-964

Jaksic, F. M., Núñez, H. & Ojeda, F. P. 1980. Body proportions, microhabitat selection, and adaptive radiation of Liolaemus lizards in central Chile. Oecologia 45, 178-181.

Lee, M. S. Y. & Shine, R. 1998. Reptilian viviparity and Dollo’s law. Evolution 52, 1441-1450.

Pincheira-Donoso, D., Tregenza, T., Witt, M. J. & Hodgson, D. J. 2013. The evolution of viviparity opens opportunities for lizard radiation but drives it into a climatic cul-de-sac. Global Ecology and Biogeography 22, 857–867.

Pyron, R. A., Burbrink, F. T. & Wiens, J. J. 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 2013, 13:93 doi:10.1186/1471-2148-13-93

Rocha, C. F. D. da 1989. Diet of a tropical lizard (Liolaemus lutzae) of southeastern Brazil. Journal of Herpetology 23, 292-294.

- . 1999. Home range of the tropidurid lizard Liolaemus lutzae: sexual and body size differences. Revista Brasileira de Biologia 59, 125-130.

Schulte, J. A., Losos, J. B., Cruz, F. B. & Núñez, H. 2004. The relationship between morphology, escape behaviour and microhabitat occupation in the lizard clade Liolaemus (Iguanidae: Tropidurinae: Liolaemini). Journal of Evolutionary Biology 17, 408-420.

- ., Macey, J. R., Espinoza, R. & Larson, A. 2000. Phylogenetic relationships in the iguanid lizard genus Liolaemus: multiple origins of viviparous reproduction and evidence for recurring Andean vicariance and dispersal. Biological Journal of the Linnean Society 69, 75-102.

Shine, R. 2005. Life-history evolution in reptiles. Annual Reviews of Ecology, Evolution, and Systematics 36, 23-46.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com!

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The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Heteromeles 11:32 am 06/26/2013

    I love the idea that all plants are created equal, and therefore that all herbivores are created equal. So what are these small-bodied herbivores eating again? Young leaves full of protein, perchance?

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  2. 2. Halbred 7:22 pm 06/26/2013

    AWWWW the Alpine chuckwalla is adorable, and I’m very jealous that you got to hold one. Was it pretty docile, or did it take some work to get him/her in that position?

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  3. 3. CS Shelton 3:30 am 06/27/2013

    Parthenogenesis happened at least once in H. sapiens, right? I kid. Blecch forever.

    I love parthenogenic squamates! So cool. Now they aren’t clones because they recombine DNA in utero (or whatever the term is), right? But doesn’t that make them hella inbred? I’m not sure how that works. But it’s lovely.

    And the association of viviparity and cold climate might mean interesting things for marine reptile evolution. Imagine a clade develops in coastal habitats, radiates north and south until it reaches colder areas, cool climate species evolve viviparity, it in turn allows them to leave the beaches completely. Right?

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  4. 4. naishd 6:33 am 06/27/2013

    Thanks for comments. Diet: judging from published comments, these lizards eat fruit, seeds and flowers more often than leaves. Plant genera mentioned in one study I just looked at (on the diet of Liolaemus cyanus) are Lycium, Atriplex, Larrea and Portulaca.

    Halbred (comment # 2): that’s not my hand :)

    Darren

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  5. 5. David Marjanović 10:18 am 06/27/2013

    And the association of viviparity and cold climate might mean interesting things for marine reptile evolution. Imagine a clade develops in coastal habitats, radiates north and south until it reaches colder areas, cool climate species evolve viviparity, it in turn allows them to leave the beaches completely. Right?

    Uh… right. Viviparity or ovoviviparity is known from ichthyo-, pachypleuro-, plesio- and mosasaurs – and from (freshwater) champsosaurs.

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  6. 6. Yodelling Cyclist 11:02 am 06/27/2013

    @David Marjanović: ….champsosaurs

    Really? Cool! Wouldn’t these be the first known “live bearing” (being deliberately vague) archosaurs? May I ask what level of proof exists for this?

    Regards
    Yod

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  7. 7. Yodelling Cyclist 11:07 am 06/27/2013

    Ok, more google time has shown that whether champsosaurs are archosaurs or not is more dubious than I had previously understood. In that case may I shift the question to one requesting informed speculation on whether the champsosaurs are in the first known live bearing archosaurs or not.

    Link to this
  8. 8. naishd 11:21 am 06/27/2013

    Yod (if that is your real name): champsosaurs are choristoderes; while choristoderes might be close to Archosauromorpha, I don’t think there are any studies finding them to be within Archosauria.

    Viviparity in choristoderes was first suggested for the Chinese Cretaceous taxon Hyphalosaurus baitaigouensis where leathery-shelled eggs were discovered within the body of an adult. The authors (Ji et al.) thought that these leathery-shelled eggs “[provide] the first direct evidence to indicate that choristoderian reptiles are most likely viviparous”, but I don’t understand why the laying of leathery-shelled eggs themselves wasn’t considered equally likely. You can see the paper for yourself here. More recently, however, unshelled Hyphalosaurus embryos were described in…

    Ji, Q., Wu, X. C., & Cheng, Y. N. 2010. Cretaceous choristoderan reptiles gave birth to live young. Naturwissenschaften 97, 423-428

    You know that probable viviparity is also known for mesosaurs now? See…

    Piñeiro, G., Ferigolo, J., Meneghel, M. & Laurin, M. 2012. The oldest known amniotic embryos suggest viviparity in mesosaurs. Historical Biology 24, 620-630.

    Darren

    Link to this
  9. 9. Yodelling Cyclist 11:40 am 06/27/2013

    @ Darren: No, no, Yod isn’t my real name. It’s just that I enjoy speculating in this environment/topic, yet it is so far from my real field of study that I’m afraid that people may assume my idiocy here bleeds across into chemistry as well (which it may well do – but I’d rather not help anybody to that conclusion). Thank you for the references.

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  10. 10. CS Shelton 2:38 am 06/28/2013

    I obviously don’t let my ignorance stop me. Why should you? I’ll probably lay off for a while once I have been sufficiently scorned by the certified scientists at hand, but I expect I’ll fall back on my evil ways again some day after that.

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  11. 11. Chabier G. 6:53 am 06/28/2013

    It’s amazing for me to see Liolaemids so close related to Opluridae. Well, not so amazing, obviously both clades would differ after Gondwana broke,Opluridae in Madagascar and Liolaemidae in South America. But Africa is occupied by Agamidae. Then, it would mean Agamidae displaced related taxa from mainland Africa and Australia, and Opluridae could only remain in Madagascar, thanks to its isolation, and it would mean that Agamidae radiation take place after Gondwana splitting. I wonder whether Agamidae fisiology have some adaptative advantage over more “Iguana-like” species.

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  12. 12. vdinets 8:23 am 06/28/2013

    Chabier: it would also mean that any introductions of Agamidae to the New World and Madagascar would have disastrous long-term consequences for Iguanids s.l. There is already a population of Agama in Miami, and I’d be surprised if they haven’t been brought to Madagascar yet.

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  13. 13. naishd 8:47 am 06/28/2013

    Yes, seeing the Madagascan oplurids so close to South American taxa is interesting (though certainly not novel). As goes the history of this section of the tree… where do the messelosaurines go? (a set of Paleogene EUROPEAN iguanian taxa). They’re sometimes said to be close to corytophanids (basilisks and kin): once their position within the phylogeny is pinned down, we might have a better idea as to what happened. I really should write about messelosaurines at length some time.

    Darren

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  14. 14. Yodelling Cyclist 10:32 am 06/28/2013

    Since there was a twitter request for comments on lizard herbivory…I’ll ask a question. How common is gut fermentation in squamates in general? I recall a talk at Chester Zoo (my childhood second home) in which a keeper discussed how larger iguanas could do this.

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  15. 15. David Marjanović 10:40 am 06/28/2013

    Ok, more google time has shown that whether champsosaurs are archosaurs or not is more dubious than I had previously understood.

    They’re probably archosauromorphs*. They’re definitely not archosaurs.

    * If you’re closer to the archosauromorphs than to, say, the squamates, you are by definition an archosauromorph yourself.

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  16. 16. Yodelling Cyclist 11:26 am 06/28/2013

    @David Marjanović: They’re definitely not archosaurs.

    I take the point. UC Berkeley (Go Bears!) appears to disagree, but I can’t find a paper that explicitly states an archosaur affiliation.

    http://www.ucmp.berkeley.edu/diapsids/archosy.html

    Interesting that archosauromorpha may include several live bearing taxa while archosauria does not. Not sure if that really implies anything significant, though.

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  17. 17. Jurassosaurus 3:22 pm 06/28/2013

    I hate being the guy that starts the off topic thread, but has anyone else noticed that SciAm seems to be stripping away features from the blog (unless Darren’s checking a box on the back end)? First the twitter feed disappeared and now the comment jump/numbers don’t show up on the front page. I tested this in Firefox, Chrome and even I.E. These features don’t show up on any of the browsers. I wonder if something is broken or in the process of breaking.

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  18. 18. naishd 4:45 pm 06/28/2013

    Jurassosaurus: I’ve noticed this stuff as well and, nope, nothing to do with me… Changes are indeed afoot, but I don’t think they have a bearing on these other issues. Hmm. I need to ask around.

    Darren

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  19. 19. David Marjanović 6:15 pm 06/28/2013

    UC Berkeley (Go Bears!) appears to disagree

    From there:

    “You will then find the small terrestrial reptile Euparkeria the next step up the cladogram. It is one of the closest known relatives to the true archosaurs, and looks a lot like what we think the first archosaur must have looked like. However, it is distinct enough that we can be confident that it is not the common ancestor of all archosaurs, and is just an early side branch outside of the Archosauria proper.”

    In short, the archosauriform Euparkeria is not an archosaur; logically (given the tree shown), the champsosaurs aren’t either.

    They shouldn’t have titled the page “Archosauria”, though. That’s just misleading.

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  20. 20. Chabier G. 2:46 am 06/29/2013

    Vdinets: These are very bad news, Agama in the new World, What species has been introduced?. Pet trade is one of the main dangers for global biodiversity, thousands of exotic reptiles are released each day worldwide. But accidental introduction by cargo ships and planes is another terrific reality. In our Rescue Center we have received two species of Canary lizards (Gallotia stehlini and Gallotia atlantica) and a Raucous Toad (Amietophrynus rangeri)from South Africa, last year, they came here in ship containers, by truck from the port of Barcelona. In the coast of Galicia (NW Spain) has been introduced, unintentionally, Tarentola boettgeri, an endemic Canarian gecko, and they are thriving there, 8 individuals each day were counted in a fruit warehouse of Zamora (W Spain), arrived among bananas imported from Canary Islands. I can’t imagine how many reptiles and amphibians are expanding their natural ranges this way, in the whole planet. The possibility of Agamidae reaching Madagascar or Fiji, and threatening unique lizards is real.

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  21. 21. vdinets 6:54 am 06/29/2013

    Chabier: A. agama. Miami is a really interesting place to see for anyone interested in introduced species: you don’t see any native lizards there, but at least 40 introduced species roam the city streets. There are also lots of non-native birds and amphibians. Look at http://www.myfwc.com/nonnatives

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  22. 22. Jerzy v. 3.0. 7:07 am 06/29/2013

    How many of these introductions spread to more-the-less natural habitat? Many introduced species only thrive in suburban, non-native and disturbed habitats, where native species are not well adapted (and nothing, frankly, is).

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  23. 23. David Marjanović 7:18 am 06/29/2013

    Aaaannnnnd 23. :-)

    (23rd is the new first!)

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  24. 24. naishd 7:22 am 06/29/2013

    Woo-hoo, we’re done! Next article to appear real soon :)

    Darren

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  25. 25. Chabier G. 7:26 am 06/29/2013

    Vdinets: Really impressive!, not only Agama, but also Calotes, and Python molurus, Boa constrictor…, Is Caiman crocodilus anyway afecting Alligator?, in Cuba, it’s been introduced, also, and it preys over young Crocodylus rhombifer. At least, Florida can have a suitable habitat for non American tropical species, but farther northward they can’t expand, I hope, to colonize the Neotropical Region.
    Here we can asess that, the bigger the town is, the higher amount of snobs inhabiting, and it means lots of exotic pets, many of them finishing released in the wild. Miami will be a great laboratory of the struggle for life with such a deal of different aliens involved. Alas, Terrific scenario for indigenous ones.

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  26. 26. vdinets 1:03 pm 06/29/2013

    Jerzy & Chabier: surprisingly few herps make it outside Miami and other areas of heavily modified habitat. The most notorious ones are Burmese pythons, Nile monitor, and Puerto Rican brown anole, but also crested-tailed iguana (mostly on W coast), Brahminy blind snake and Cuban tree frog. Caimans were at a peak around 1970-80, but then the Air Force waged an extermination campaign around its base at Homestead (the main center of the introduced population), and almost killed them off. There was only one record in the Everglades, and that was decades ago.
    So far, the only ones successfully colonizing non-urban habitats outside Florida Peninsula are the brown anole and the Mediterranean gecko (but the latter mostly sticks to buildings).

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  27. 27. naishd 6:04 pm 06/29/2013

    On the subject of alien lizards, I was just looking at the latest ish of Biawak (a journal devoted to monitor lizards), and therein we find…

    Soler, J. & Martínez-Silvestre, A. 2013. Feral monitor lizards (Varanus spp.) in Catalonia, Spain: an increasing phenomenon. Biawak 7, 21-24.

    Darren

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  28. 28. vdinets 1:06 am 06/30/2013

    Which species? I would imagine V. griseus would be a good candidate for more arid parts…

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  29. 29. David Marjanović 7:39 am 06/30/2013

    the Mediterranean gecko (but the latter mostly sticks to buildings)

    I see what you did there. :-)

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  30. 30. Hai~Ren 8:09 am 06/30/2013

    A similar phenomenon has been going on in Singapore – Calotes versicolor was introduced a few decades ago, and is suspected to have displaced the native Bronchocela cristatella from urban & suburban gardens and parks. Just last year, brown anoles were first recorded, having presumably hitchhiked with plants imported for a new botanical attraction in the city. Every once in a while, people encounter feral green iguanas, although the trade in nearly all reptile species for the pet trade is banned here. And I’ve heard that there is a breeding population of green iguanas where a now-defunct reptile park was situated.

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  31. 31. Chabier G. 10:09 am 06/30/2013

    Wow!, monitor lizards in Catalonia. Well, in the 2009 issue of the Atlas of Amphibians and Reptiles of Spain, Varanus niloticis is cited in Andalucía (at least 3 individuals in different places), and Catalonian Governement lists this species as “introduced, non stablished”. I think colonization of Iberian Peninsula by this lizards is a statistical matter, if they continue escaping, and some individuals gather in the same place, specially in Andalucia, they will succeed. Catalonia is too populated and plenty of roads, perhaps, but the climate is also mild.
    In Iberia we have two rare examples of island endemic lizards introduced and…displacing their continental counterparts. One is the Madeira Wall Lizard (Podarcis dugesii), introduced by ship trade in the port of Lisbon, now thriving and displacing Podarcis hispanica. The other is Podarcis pityusensis, endemic of Ibiza and small neighbouring islands, introduced intentionally in the tiny rocky Island of Gaztelugatxe, in the Basque Country (joined to the mainland by a road), about 30 years ago, now the indigenous Podarcis muralis has disappeared and the island shelters a dense population of Ibiza wall lizards.
    It can look weird, but there are really dangerous stupids out there that deliberately introduced exotic species, not only single releases of discarded pets, but accurate releasing of founder populations, as seen in the case of these Ibiza lizards or the Tropidurus breeding population recently extirpated from La Palma (Canary Islands). Globalization and idiocy going together can be very dangerous.

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  32. 32. Heteromeles 5:41 pm 06/30/2013

    It doesn’t sound weird, it’s just very, very old. Ask how goats got to La Palma, for example. Charles Mann called it “reknitting the seams of Pangaea.”

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  33. 33. Dartian 2:26 am 07/1/2013

    Chabier:
    The possibility of Agamidae reaching Madagascar or Fiji, and threatening unique lizards is real.

    I don’t know if it has reached Madagascar yet, but Calotes versicolor is already present on such relatively nearby Indian Ocean islands as the Mascarene Islands (including Mauritius, pers. obs.) and the Seychelles. It also seems to have gained a small foothold on the African continent, in Kenya (Šandera & Starostová, 2009). This species eventually reaching Madagascar thus seems more than likely.

    Reference:
    Šandera, M. & Starostová, Z. 2009. A record of Asian agama of the genus Calotes Cuvier, 1817 (Squamata: Agamidae) in Kenya. Bonner Zoologische Beiträge 56, 225–228.

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  34. 34. Chabier G. 3:19 am 07/1/2013

    Heteromeles: Yes, deliberate introduction of species is very old, but in the old times people release in the islands useful animals in order to have a living larder for passing ships: goats, swine and the like.Even foxes in Crete, Pine Martens in Menorca and other animals in many Mediterranean Islands were introduced by neolithic sailors, probably cause of their fur. The new thing is the introduction of alien species only for some kind of self gratification, as in the case of the Canarian Tropidurus, Alpine Newts in Central Spain, Ibiza Lizards in the Basque Country, etc.

    Link to this
  35. 35. Heteromeles 9:32 am 07/1/2013

    @34: or porcupines in Italy? I think the Romans did that.

    But yes, I agree, there’s a whole lot of stupid going on right now. While I haven’t seen too many exotic reptiles in my area, I do know where some doltish “hobbyist” laid down a bunch of plywood boards as “snake shelters” in a natural area. Some of our local native snakes are uncommon morphs of uncommon species, and I can only suppose whoever did it is part of the illegal pet trade. Unfortunately, I don’t have a good way of walking them out and disposing of them. Perhaps I should just go in there with a pickaxe, after making sure they’re unpopulated?

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  36. 36. naishd 11:21 am 07/1/2013

    More alien lizards: I happened to check the latest ish (April 2013) of Pacific Science today. It includes an animal reviewing occurrence of Iguana iguana across the Pacific: there are individuals on Fiji, Hawaii and Japan at least, some of them belonging to breeding colonies.

    Darren

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  37. 37. vdinets 1:50 am 07/2/2013

    If iguanas and anoles can so easily colonize parts of Agamid domain (and we are talking places with lots of Agamids), doesn’t it kill the idea that the disjunct Iguanuid distribution is a result of hostile Agamid takeover? Although I don’t have any alternative explanations…

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  38. 38. Chabier G. 2:36 am 07/2/2013

    Perhaps the ancient Iguanid species displaced by agamids can’t be compared with modern, adaptative taxa like Iguana or Anolis. But the presence of Iguana in Fiji could be the final disaster for the endemic and already threatened Brachylophus, Iguana is bigger, eats the same, it’s far more prolific, and it’s used to predators, I think it has advantages dealing with mongooses, cats and rats, some of the threats to Brachylophus.

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  39. 39. vdinets 9:18 am 07/2/2013

    Chabier: Anolis might be a recent invention, but the remaining Old World iguanas (the ones on Madagascar and Fiji) are very dissimilar, and show that the whole range of forms, from small terrestrial arid-land species to large arboreal rainforest ones, was once present. It’s hard to imagine that all of them lacked the ability to adapt to Agamid presence.

    Interestingly, it looks like Agama agama has been introduced to Madagascar, but failed to establish: go here.

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  40. 40. Chabier G. 3:11 am 07/3/2013

    Vdinets: I agree, it´s hard to believe in an intrinsic superiority of Agamids as a whole group over Iguanids sensu lato, both clusters have many diverse ways of life, feeding sources, habitats, etc. But the facts are there, if we look at current distributions, it seems that Iguanids have a Gondwana origin and were swept by Agamids from these Gondwana fragments that contacted with Laurasian lands,from where, I supose, Agamids were originated. Maybe Agamids carried pathogens lethal to Iguanids (in birds and mammals, at least, some Bacteria and Protozoa follow a “taxonomic” rather than a biogeographical distribution pattern. Or maybe current distribution is the result of other, unknown events. After all, current distribution of Marsupials could make us think they have a Gonwanan origin, but the oldest Marsupial fossil has been found in China.
    And about that Madagascar Agama, well, it seems only one individual was seen…

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  41. 41. David Marjanović 9:49 am 07/3/2013

    if we look at current distributions, it seems that Iguanids have a Gondwana origin

    See comment 13.

    the oldest Marsupial fossil has been found in China

    That’s the oldest metatherian; the name Marsupialia is now often restricted to the crown-group, which most likely did originate in South America right after the Cretaceous was over.

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  42. 42. Chabier G. 3:21 am 07/4/2013

    Oh, yes, I’ve commited two mistakes at least, Sinodelphys can’t be called a true marsupial, and if Messelosaurinae are close related to Corytophanidae, we can hardly suppose a Gondwana origin for non acrodont Iguania. And then, real events were far more complex than a simple adaptative superiority of Agamidae over other Iguania.

    Link to this

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