All posts by Jonathan Losos

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.

Egret Eats Green Anole

Photo by John Karges

Photo by John Karges

We’ve seen this before. Anoles are, alas, no match for these large and wily marauders. John Karges provides the story: “The egret was flying down the riparian woodland corridor over a side channel, and abruptly landed in the mid-story thicket overhanging the stream and immediately began a stalk. It lunge-grabbed the anole, and very quickly devoured the adult anole in a matter of seconds.”

And here’s where it went down: 2 Oct 2016 San Antonio Mission NHP, San Antonio, Bexar County, Texas.

And the inevitable outcome.

Photo by John Karges

Photo by John Karges

Concerns Raised over Introduction of Festive Anole to Bermuda

From the September 28, 2017 edition of The Royal Gazette, the daily newspaper of Bermuda.

Fears over lizard arrival

Jonathan Bell

  • Thriving: the brown anole, a new lizard species believed to have arrived from Florida (Photograph supplied)

Bermuda’s latest lizard arrival, the brown anole, appears to be thriving but is prompting concern over the island’s endangered natives.

The lizards, first seen in 2014 and recently spotted on the grounds of Aberfeldy Nursery in Paget, are suspected to have arrived from Florida.

One of that state’s most abundant lizards, the anole arrived there from the Caribbean, where it is native to the Bahamas and Cuba.

Popular as pets but aggressive breeders in the wild, the lizard, distinguished by ridges on its back, has proliferated in the southern United States.

According to the Department of Environment and Natural Resources, Bermuda has two distinct populations of brown anoles.

Genetic analysis shows that the two groups came from “separate founding events”, meaning the second did not arise from the first.

Noting the lizard’s capacity to spread rapidly, Jonathan Starling, executive director of the environmental group Greenrock, voiced concern that the anole would ultimately crowd out Bermuda’s imperilled skinks.

“Unlike the three other Anolis species known to be in Bermuda, the common blue Jamaican, the Warwick or Antiguan and the Barbados, this one is primarily a terrestrial species, the rest being arboreal or tree dwelling,” Mr Starling said.

“The endemic Bermuda skink, already at critically low populations, is also a primarily terrestrial species, so this new lizard poses a much bigger threat to it than the others did.

“I am not aware of the current range of this new lizard but I believe it is still confined within Pembroke and Paget parishes, so at the moment it is not coming into conflict with the remaining known skink populations. However it is likely their range will expand and come into contact with known skink populations within a decade, if not sooner.”

The unwelcome development is the latest of many threats to the endemic skink, which are easily trapped and killed by discarded bottles and cans.

Skinks are also at jeopardy from storms, as well as predation from other invasive species such as cats and rats.

“We’d hope that new initiatives, such as mandatory recycling or a bottle bill, would at least reduce that particular threat to skinks, which would likely benefit them in handling the novel threat posed by this invasive lizard,” Mr Starling said.

Dying Anoles with Eye Problems in Louisiana

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AA reader Jonathan McFarland sent in these disturbing photos with the following remarks:

“I hope you can shed some light on what’s happening to the wild anoles in my Louisiana suburban yard. This week I have found two adolescents with both eyes bleeding or infected. The attached pictures show only one side of the specimens but in each case both eyes appeared as shown. Any info you could provide would be much appreciated.”

Thoughts, anyone?

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Knight Anoles Introduced to Another Island: Abaco, Bahamas

Photo by Joel Sartore

The knight anole is really getting around these days: Turks & Caicos, Grand Bahama, Grand Cayman and many other islands. Now they’ve  made it to Abaco, Bahamas, where one individual was captured and possibly two others seen (see article in IRCF Reptiles and Amphibians)Abaco Scientist has an insightful discussion of introduced reptiles and amphibians on Abaco.

Female Green Anole with Sand on Her Head–Been Egg-Laying?

Photo-chronicler of Floridian natural history Karen Cusick has done it again. We’ve been captivated by her backyard photos before, but here’s photo of a female green anole with sand on its snout. Been digging holes to bury her eggs, maybe? And while Karen observed the little lady lizard, it suddenly darted into the bushed and emerged with a meal!

 

Shades of Bumpus: Polar Vortex-Induced Natural Selection on Cold Tolerance in the Green Anole

Shane Campbell-Staton had fortuitously measured the thermal physiology of a number of populations of the green anole, Anolis carolinensis, the summer before 2014’s Polar Vortex. So, he went back and examined the survivors. And sure enough, in the most southerly populations, those most strongly affected by the cold snap, natural selection had occurred. Shane tells Scientific American all about it in this podcast. The nifty figure above comes from the University of Illinois’ press release.

 

More Information on the Knight Anole Invasion of the Turks and Caicos

We reported recently that knight anoles (Anolis equestris) have shown up in the T&C. Here’s more on the story from B Naqqi Manco, the Terrestrial Ecologist at the Department of Environment and Maritime Affairs, Turks and Caicos Islands Government:

Cuban knight anoles are currently known from two sites on Providenciales: Vicinity of Beaches Resort in The Bight and Amanyara Resort on Northwest Point. Both populations showed up after the importation of large trees for landscaping from Miami. The properties are both irrigated pretty heavily to keep the bigger trees going. The tree imports were brought in before the Department of Agriculture was fully operative, so unfortunately things got in at that time that probably shouldn’t have made it through.

I don’t have confirmation of the knight anoles breeding, but I know The Bight population has been spreading with individuals having been found on adjacent properties and in a nearby residential neighbourhood. I would be very surprised if they’re not breeding on either site. Unfortunately we don’t have the capacity to monitor them well but this is something we want to keep a closer eye on and it would make a worthwhile research project for a student or intern. 

Thus far, they have not been reported from any other island or cay. 

Book Review Rebuttal: Are Honduran Anoles Overly Split?

Two years ago, McCranie and Kohler published The Anoles of Honduras: Systematics, Distribution, and Conservation(available on Amazon for under twenty bucks and downloadable for free on the Museum of Comparative Zoology website).

In turn, two mostly favorable reviews were published. However, one of the reviews, by Levi Gray, did question whether a number of anole species recognized from small distributions in Honduras should be recognized as valid species, rather than just as populations of species that are widespread throughout Central America.

Writing in Zootaxa, Randy McCranie has now responded to this point, forcefully arguing that the species should be recognized and challenging his critics to present their own data if they feel otherwise. You’ll have to read Gray’s review and McCranie’s rebuttal yourself to decide what you think. Gray made his skepticism clear, he also did clearly call for more research to address the question.

More on the Lizard Species Whose Dewlap Differs from One Side to the Other

dewlaps

These pages have previously told the tale of Anolis lineatus, the species whose dewlap is different on one side compared to the other. Now the work has been published in Breviora. Like all publications of the Museum of Comparative Zoology, the paper can be downloaded from the museum’s publications webpage.

The research project was actually explained in a delightful video put together by the three joint first authors, all of whom are headed to college this fall.

curious case

A Green Anole That’s Blue

Photo by Carissa Wickens

Photo by Carissa Wickens

Eileen Wickens, who just finished the fourth grade in north central Florida, is a lizard-catching machine and particularly adept at nabbing blue-colored green anoles (Anolis carolinensis). Here’s the story, relayed by her mom, Carissa:

The teal lizards do seem rare as we have only seen a few. We had one at our house last spring and the photo I sent you was taken at our horse teaching unit in Gainesville. We were running an equine behavior trial that day (we’re actually investigating startle phenotypes and genetics in our Quarter Horse herd), and I saw the lizard as we were packing up our gear. My daughter is very good at spotting and catching them, so we will definitely keep our eyes out and would be happy to provide a specimen for your genetic research if we can. I’ve attached the photo of the lizard we had at the house last spring. The green anoles are scare in our neighborhood and on campus compared to the brown anoles (short snouts with distinct, dorsal diamond or striped markings). They seem to far outnumber the greens. 

From our brief observations of those two blue lizards this past year it does not appear they turn the bright green you see on the other Carolina Anoles, but it would be good to observe them for a longer period of time to be certain. 

Evolution 2017: Sensory Drive and Lizard Adaptive Radiation

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The Sensory Drive hypothesis predicts that species will evolve communication signals that are effective in the particular light environment in which they occur. Anolis lizards are an excellent example: in dark habitats, they tend to have light-colored, highly reflective (and transmissive) dewlaps that are usually yellow or white in color, whereas in bright, open environs, dewlaps tend toward blue, black, orange or red. However, demonstrating that these dewlaps are actually effective at being visible in their particular habitats has proven surprisingly challenging.

Leo Fleishman has been a leader in this area and in a talk at the sensory ecology symposium at the evolution meetings, he presented new and exciting developments. First, in line with previous work, he showed that the spectral reflectance/transmittance of dewlaps is not particularly well-matched to that of the background. Rather, the same colored dewlaps appear to be maximally contrasting with the radiance of the background across all habitats:  basically all habitats have mostly green backgrounds, and red or orange stands out the best against the green background, no matter what the habitat.  So much for sensory drive, it would seem!

But more recent work saves the day: it turns out that habitats differ in the total intensity of light (number of photons coming down) they receive and that, furthermore, across species, dewlap intensity (total photons reflected and/or transmitted) is negatively related to habitat intensity (with one notable outlier, the enigmatic A. gundlachi). Under the relatively low light conditions of forest shade or partial shade, color discrimination becomes more difficult, and colors such as red and orange and other dark colors do not stand out well against the background, because they simply do not emit enough photons to efficiently drive color vision.  Yellow or white works better. Conversely, in intense light environments, there is enough light to easily see the darker colors, and these stand out well against the green background. Moreover, behavioral experiments confirm that in bright light conditions red stimuli are most visible against a green background, whereas in low light yellow stimuli are more visible.  Thus, even though most Anolis habitats have similar spectral properties, differences in total light intensity strongly influence what colors are most effective, and thus appear to have played a major role in the shaping the evolution of dewlap colors.

Leo Fleishman discusses color space in 4-dimensions, corresponding to the four cones in the anole eye. For each species, red dots are color of the dewlap and green dots are the color of the background, indicating that dewlaps stand out against their background.

Leo Fleishman discusses color space in four dimensions, corresponding to the four cones in the anole eye. For each species, red dots are color of the dewlap and green dots are the color of the background, indicating that dewlaps stand out against their background.