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When I think of colour and pattern in lizards, I tend to think about showy visual displays. An example that springs to mind is this fantastic footage of Draco lizards using multiple appendages as colourful signals.

But despite all the effort an individual lizard puts into signalling to conspecifics, it must constantly remain wary of predators. Mimicry and camouflage are tried and tested means by which to evade predation, but little effort has been made to quantify the colours and patterns that may help lizards escape being eaten. Research presented by Danielle Klomp from the University of New South Wales at the Animal Behaviour Society 2014 meeting addresses this question in Draco cornutus, a South East Asian agamid lizard that uses the patagium, an extendable membrane attached to elongated rib bones, to glide from tree to tree.

Sampling in two populations of D. cornutus, Klomp noticed that though individuals in the two populations had identical dewlaps, they differed substantially in the colour and pattern of the patagium. Remarkably, the colours exhibited in each population seemed to perfectly match the colour of falling leaves of trees in the same habitat.

Patagia and falling leaves from two populations of Draco cornutus. Photos by Danielle Klomp.

By measuring spectral reflectances as well as the proportions of black on lizard patagia, falling leaves, foliage, and dead leaves, and accounting for how these colours might appear to predatory birds, Klomp demonstrated that in both colour and pattern, D. cornutus patagia in each population most closely matched falling leaves in the same population. This suggests that Draco are especially vulnerable to predation while gliding, and have undergone strong natural selection to mimic non-prey items in the particular environment they experience while gliding.

Here’s a link to Klomp’s poster from the International Society for Behavioural Ecology 2014 conference, and here’s a link to a blogpost about some very cool technology that Klomp used to make her poster come alive while presenting it.

From Rachel on Twitter.

Wouldn’t this be great? Maybe there’s one out there, still waiting to be discovered.

httpv://vimeo.com/93621704

We’ve discussed the crisis concerning Jamaica’s Goat Islands previously. This film is the work of Robin Moore. Read more about the film and the efforts to preserve Jamaica’s iguanas on National Geographic‘s Newswatch. More relevant videos can be viewed at the Save Goat Islands website.

Here’s the first lizard talk from the Animal Behavior Society meetings! This is a guest post from Holly Brown, who studies visual and foraging ecology in herons at UConn.

Eye structure is remarkably similar among vertebrates. Therefore, one might, understandably, imagine human visual experiences to be representative of visual experiences across vertebrate taxa. However, this is not the case. Two important differences between mammalian and non-mammalian vertebrate vision are that, unlike us, the latter are able to move their eyes independently of one another, and they seem to lack stereopsis. Stereopsis is the ability to view the two independent images generated from each eye as a single image, which ought to make depth perception easier, and thus aid in important tasks such as capturing prey.

So instead of studying mammals, Gadi Katzir and his team of collaborators from the University of Haifa, Israel, are studying chameleons to better understand vertebrate vision.

Common Chameleon by Benny Trapp from Wikimedia

One of their recent experiments was aimed at finding out whether or not chameleons could simultaneously track two prey items independently with each eye, and if so, how independently (of one another) were the eyes able to move. They found that chameleons could simultaneously track different prey items with each eye, but at some point, they would always make a choice to converge both eyes onto their eventual prey target. Furthermore, they found that chameleons never struck at prey with their eyes still diverged. By pursuing this line of research, Katzir and his team may be able to glean insights as to how stereopsis may have evolved.

Anole jeans! Now marked down to $25. Get ’em while they last!

Extensive googling reveals that the jeans are made by Nice Work Textile Jeans, Inc.

Long time AA readers will know that anoles frequently pop up in haute couture, perhaps most recently when Tommy Bahama created an anole-colored T-shirt.

Distribution records for Anolis cristatellus in Costa Rica reported in 2011 AA post.

Four years ago, we reported on the distribution of the Puerto Rican crested anole all along the Caribbean coast of Costa Rica. We also found the species inland, as far west as Turrialba and Siquerres, but not Guapiles (see map to right). A year later, we returned for a quick follow-up as part of a herpetology course spring break trip to Costa Rica. The weather wasn’t great and we failed to find cresteds in any place not previously reported; however, observations of brown basilisks, another sun-loving species, suggested that the weather was suitable enough, and that perhaps the absence of the anoles was real.

Two years later, this past March, another herpetology class trip ensued, and so another expedition was launched to Guapiles and environs. The team included AA correspondent Katie Boronow, an award-winning senior with expertise on A. cristatellus, and a sophomore in training for Miami field work this summer (more on them in posts to come).

And the results???

Read More

The journal Herpetological Review, published by the society for the Study of Amphibians and Reptiles, frequently has interesting anecdotal reports of natural history observations of anoles. This quarter’s edition has two: nocturnal activity in Anolis cristatellus and prey stealing behavior in Anolis sagrei. Here is a synopsis:

Dean and Jennifer Metcalfe report on nocturnal behavior of A. cristatellus wileyae observed (while perhaps on vacation) at the Nanny Cay Resort and Marina on Tortola, British Virgin Islands. The authors observed that the subject anole had navigated the interior of their hotel room in near darkness after dusk, selecting a nocturnal perching site on a lampshade. They suggest that this is similar behavior to that of an anole selecting an arboreal perch site at dusk. Two questions come to mind though. First, whether the room was completely dark- as the authors acknowledge that some light might have been entering the room- and whether the animal came from the outside into the room to perch or was residing in the room. Second, the author mentioned that this was the only anole seen on Tortola during her brief stay, which is also a bit unusual as the species should be abundant there. This might not add much to our understanding of anoles, but it certainly raises some questions about the co-habitation of humans and anoles.

The second note comes from David Delaney, a master’s student in Dan Warner’s lab at UAB, and friends, who report on an opportunistic A. sagrei in Ormond Beach, Florida. The anole had apparently been observing a predation attempt of a spider-wasp on a funnel-web spider. To summarize, the wasp attacked and envenomed the spider, captured it, and began dragging it across the ground. At this point the anole jumped to the ground, grabbed the spider, and took it up the tree to eat it. The wasp, likely disappointed, fled the area to hunt again.

Metcalfe, DC and JE Metcalfe. 2014. Anolis cristatellus wileyae (Vrigin islands Crested Anole). Nocturnal Activity. Herpetological Review 45: 323-324.

Delaney, DM et al. 2014. Anolis sagrei (Brown Anole). Prey stealing behavior. Herpetological Review 45: 324-325.

Great photos on Adventures Down South

Where do anoles poop? Will they chase laser points? Find out on Casey Gilman’s new blog on her Florida field research, Adventures Down South.  Meanwhile, Chipojolab keeps the world abreast of goings-on in the Leal Lab. Most recently–Leal back in the Bahamas and multiple lab members cavorting in Puerto Rico! And Ambika Kamath’s afoot with her field crew in Gainesville, dodging frisbees and fire ants in quest of the wily festive anole. Finally, at Lizard and Friends, Michele Johnson talks about Puerto Rican anoles that are biting off more than they can chew. Or are they?

Do you have a blog on your research? If so, let us know!

Field laboratory in Puerto Rico. Read all about it in Chipojolab.

Andrew Battles from the Kolbe Lab gave a talk at JMIH presenting data on performance-habitat relationships comparing lizard performance on rough and smooth surfaces. The data were collected on Guana Island in the British Virgin Islands using Anolis cristatellus and A. stratulus as study species. Andrew and his advisor, Jason Kolbe, were interested in whether lizards perform differently on artificial and natural surfaces.

Major differences between natural and artificial habitats

They used three different running tracks (37°-incline rough track,  90°-incline rough track, 90°-incline smooth track), assuming that artificial surfaces are smoother than natural ones. The rough tracks consisted of a board covered in window screen and the smooth track was a plain 2-by-4 board. They used a high-speed camera to measure maximum velocity, how often a lizard paused during the run and how often it slipped. While both species ran significantly slower, paused and slipped more often on the smooth surface, A. cristatellus performed even worse than A. stratulus. Andrew and Jason then conduced a field survey to test whether lizards in a human-modified habitat use both artificial and natural perches. In addition, they rated roughness of natural and artificial perches. When both types of perches were available, lizards used artificial perches more often than natural ones.

In human-modified habitats, lizards were found mostly on artificial perches

This is surprising, because artificial perches are significantly smoother than natural ones and lizards perform worse on smooth surfaces. Possible explanations are that other factors such as food availability and/ or predation may drive habitat selection on artificial substrates.