A year 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 case you missed them, we thought we’d provide copies of some recent reviews of the book–in the last year, two favorable book reviews have appeared by Levi Gray in Herpetological Review and by Steve Poe in Quarterly Review of Biology.
In one of the few anole talks here at the annual Ecology meeting in Ft. Lauderdale, Florida, James Stroud presented on a project he conducted with the Fairchild Tropical Botanical Garden, Jason Kolbe, and others. Together, they organized a large citizen science project engaging middle-school aged students to collect distribution and abundance data about anoles in the Southern Miami region in a program they call “Lizards on the Loose.”
In this outreach project, James and colleagues had 101 schools participate in collecting data. Armed with a handy anole ID guide created by Jason Kolbe and a video by James explaining anole biology and species differences, students and teachers set out to conduct 15 minute visual surveys. On these surveys, they recorded how many animals they encountered, the species ID, and the approximate body size using a provided standardized collection protocol and entering data into a Google forms site.
The results were overwhelming: more than 1,000 students conducted a total of 1,356 surveys resulting in 12,000+ lizard observations! This project produced massive amounts of data on very short time frames. In general, distribution patterns fell as they were expected to, although some records certainly hint at some mis-identification (e.g. some A. cristatellus locations). Unsurprisingly, the least abundant lizards were those that were hardest to detect: the species typically found high in trees.
While the resulting dataset is impressively large, James admits that there are data quality issues with collecting data in this manner and asked for input on how to improve data collection. Specifically, he suggested that in the future they would like to incorporate photographic and smartphone GPS information, perhaps via an app. Does anyone have any suggestions for James on implementing such an app or otherwise improving the design?
James emphasized that providing meaningful natural experiences with wildlife for kids is good for conservation, fosters an appreciation for nature and helps inspire the next generation of scientists. Many of our readers may find inspiration from the success of this program and we would love to hear about it if you implement similar types of citizen science projects with anoles!
Anolis sagrei
From time to time, people find anoles with broken dewlaps. Here’s an extreme example, found by Bob Powell and Rich Sajdak on the island of Grenada. Years ago, Richard Tokarz reported a lab study that showed that males with non-functional dewlaps mated as frequently as intact males, and a follow-up study with Ann Paterson and Steve McMann showed no difference in the field between males with and without working dewlaps. Makes you wonder what the dewlap is needed for.
Bob points out that brown anoles have spread widely in disturbed lowland habitats since first discovered on Grenada in 2002, when they were restricted to intensely disturbed urban habitats and decorative plantings in a few resorts.
All evolutionary biologists are familiar with Robert Trivers, but many do not know that some of his most important work was conducted on Anolis lizards. This work–as well as the rest of Trivers’ life–is featured in his just-published memoirs, Wild Life: Adventures of an Evolutionary Biologist. I had the good fortune to review the book for Current Biology. You can read my review, but the short story is: a fascinating book about one of the great figures–and characters–of modern evolutionary biology. And in case you’re wondering, it was the publishers who put a collared lizard, instead of an anole, on the cover. Available on Amazon for $12.99!
Effect of perch treatment on (A) latency to reproduce and (B) yolk corticosterone.
Competition for perches has been an important factor in the diversification of anoles. Yet, we know little about the influence of perch availability on reproduction. To address this, Dan Warner, Matt Lovern, and I housed male / female pairs of brown anoles (Anolis sagrei) in treatments with either high- or low-availability of perches (Fig. 1).
We found that females reduced how often they used perches when perches were limited. More interestingly, though, when perches were limited, females tended to take longer to begin laying eggs (for the first time in a season; p = 0.063, Fig. 2A) and allocated more corticosterone to egg yolk (p = 0.069, Fig. 2B), although these findings were not statistically significant.
Figure 2. Effect of perch treatment on (A) latency to reproduce and (B) yolk corticosterone.
In many habitats in which brown anoles occur, organic perches are abundant and not likely to be limited. However, in urban areas or on some islands anoles have colonized, perches can be limited. Our study suggests that such habitats may have consequences for reproduction.
Citation for the full paper:
Delaney, DM, MB Lovern, and DA Warner. 2016. Does reduced perch availability affect reproduction in the brown anole? An experimental test in the laboratory. Journal of Herpetology 50:227-232.
Remarkably little is known about the natural history of the Puerto Rican twig anole, Anolis occultus, except where it sleeps. The reason is simple: the
animal is small, moves slowly, is highly cryptic and probably spends a lot of its time amidst the twigs high in the canopy. As a result, there have been reports of only a handful of animals located while they are active.
In a just published paper, Ríos-López and colleagues report two new observations of these charming little lizards, one of nectarivory (above) and the other, sadly, of predation by a kingbird (right). In addition, the paper presents a comprehensive review of what we know about this species and its conservation prospects.
Anolis chlorocyanus after gliding back to the tower. Photo by Brian D. Farrell
Every summer, a group of students heads down to the Dominican Republic to take the Harvard summer course on biodiversity of the country. As a teaching assistant, I often watch unsuccessful attempts of students trying to catch the abundant fast-moving lizards. Sometimes I also participate, usually resulting in the same outcome. Last week, we were climbing an observation tower in Punta Cana to spot Ridgway’s hawks (Buteo ridgwayi) when Ryan Friedman, a student taking the course, noticed a Hispaniolan green anole (Anolis chlorocyanus) perched on the side of the tower. We thought we would finally outsmart an anole and catch it with our hands. However, the lizard apparently preferred to jump to certain death rather than being handled by us. We watched it falling down about 10 meters, but, instead of going straight down and hitting the ground, it followed a curved trajectory that safely brought it back to the tower (and enabled Brian Farrell, the course instructor, to take a picture after the fact).
This observation seemed remarkable enough for Jonathan Losos to allow this entomologist to report it here, and also made me very curious. Are some anoles able to direct their fall, or maybe to glide with the wind while they go down? Hopefully someone will have the chance to do a controlled trial and figure it out!
Editor’s Note: Such behavior has been noted for Anolis pentaprion.
Alberto Puente-Rolon (Universidad Interamericana de Puerto Rico, Recinto de Arecibo) and I were incredibly fortunate to spend a week on the Cay Sal Bank, Bahamas. Cay Sal is a partially emergent island bank situated about 100 km south of Islamorada in the Florida Keys and about 50 km north of the Cuban Bank in the vicinity of Sagua la Grande. Politically part of the Commonwealth of the Bahamas, the bank is separated from the Great Bahama Bank by the 47 km-wide Santarem Channel, and is about 175 km west of the southern tip of Andros Island. Cay Sal Bank is a shallow carbonate platform with dozens of small emergent islands around the edges of the roughly triangular-shaped bank.
Anolis sagrei, Cay Sal Island. Photo by Alberto Puente-Rolon.
A note before we launch into the narrative of our trip. The Cay Sal Bank is an area known for a significant amount of illegal activity. This largely involves illegal fishing fleets and human trafficking. While a typical visitor to the area would not likely be in great danger from these activities, there is always the possibility that you might run into the wrong people at the wrong time. Illegal fishing vessels have been known to harass, intimidate, and attempt to board cruising vessels on Cay Sal, while happening upon a human or drug trafficking exchange could be extremely dangerous. We saw evidence of all of these activities during our cruise, and mention some specifics in the narrative below. In addition, the Cay Sal Bank is remote. There are occasional Coast Guard planes in the area, but keep in mind that there might not be many vessels able to monitor emergency radio channels (channel 16) or respond quickly to an emergency. We cruised to the region with a highly experienced crew and a very well maintained and outfitted vessel, and we recommend anyone else planning to visit do the same, as well as consider taking all available safety precautions. I am happy to discuss my experiences in detail with researchers interested in visiting the area.
Anolis fairchildi, Cay Sal Island. Photo by RGR.
We arrived on the bank at dawn after an overnight cruise from Bimini, where we had cleared Bahamas customs and immigration. Our first stop was Dog Rocks, where we were able to disembark and swim ashore for a short walkabout on the largest of the small rocks jutting out of the ocean. The Dog Rocks mark the eastern edge of the Cay Sal Bank, and as far as we were aware there were no herpetofaunal records from these islands. Most are rocky and jagged, likely washed over during hurricanes and largely devoid of vegetation. Great Dog Rock is quite small, with a patchy covering of ground vegetation. There is a single large, pyramid shaped stand of Cocoloba uvifera near the center of the island-
Cocoloba uvifera stand on Dog Rocks. Photo by Alberto Puente-Rolon.
approximately 5 meters high and 10 meters wide. Quite a few Sooty Terns (Onychoprion fuscatus) and Brown Noddies (Anous stolidus) nest here. Even in this very isolated and largely barren stretch of rocks, we managed to locate Anolis sagrei. The large males and robust females were mostly occupying the Cocoloba stand, though we did find juveniles, young males, and females on the ground near the scrub vegetation. We even located a juvenile underneath a discarded conch (Strombus gigas) shell. We spent about two hours here, plenty of time to survey the entire island. We did not find evidence of any other terrestrial reptiles, and it is quite remarkable that even A. sagrei could persist there.
Departure from Cay Sal Island. Photo by RGR.
Our next stop was at the Damas Cays, a small group of narrow, high-walled islets jutting out along the spine of the eastern Cay Sal Bank. Like Dog Rocks, we are unaware of any herpetofaunal records from Damas, and for good reason. We took a rigid inflatable boat out for a brief survey of the largest of the Damas Cays. There are no easy landing spots on the island, so landing would require a swim. There was very little vegetation, we spotted a single small shrub and some very sparse groundcover. As we approached the island to land, we lost power on our outboard engine and were losing daylight, so we opted to repair the engine and not to clamber ashore.
Cay Sal Island. Photo by RGR.
We then cruised across the bank to the southwestern edge, about 80 km from Cuba.
Not a dewlap? Photo by Morley Read.
In a recent paper, Hagman and Ord discussed how dewlaps have evolved multiple times, often with different underlying anatomy. This is an excellent paper, but I was intrigued that Polychrus, sometimes considered the sister taxon to anoles, in part because of its apparently anole-like dewlap (see above), was not considered to have a dewlap.
I wrote Terry Ord, asking “I didn’t understand one thing. You seem to say there is no evidence for extendible dewlaps in several species of Polychrus, but a quick Google reveals plenty of images of these species with dewlaps extended. I take your point in the previous sentence that actual observations of the dewlap being used are rare, but did you really mean to say that they don’t exist at all?”
Terry responded: “What I found when attempting the first paper of this series (Ord et al. 2015, Journal of Evolutionary Biology) is that relying on photos alone is really problematic for identifying a moveable dewlap (a.k.a., a dewlap like anoles or Draco or Sitana).
For example, if you google Sceloporus — who definitely don’t have dewlaps — you’ll find photos where species do appear to have something like a small dewlap. In fact, I found an image of what was clearly a Sceloporus that looked to have an engorged throat that was remarkably similar to your Polychrus photo… All the google images I’ve found so far that are obviously Polychrus (and not anoles) could quite easily be engorged throats akin to Sceloporus and other non-dewlaped iguanids/agamids.
But the clincher for me is that all the hyoids we’ve looked at so far for both Sceloporus and multiple species of Polychrus (and other non-dewlaped iguanids/agamids) all look very similar (e.g., see Fig 5a in the JEB paper and supplementary info). The point being, the mechanics of the hyoid simply isn’t functional in the capacity of extending a dewlap like in anoles and others.
Of course, while the mechanics of the hyoid in extending the dewlap in anoles is well described, how Draco do it and some other genera is unclear. I’m hoping someone will look into detail on the biomechanics of the dewlap extension in non-anole groups because it can clearly be very different to anoles — e.g., the attachment points for key muscles for the anole dewlap are absent in Draco, so they’re sticking that dewlap out using a very different mechanism. Regardless, there are still key signs in the hyoid that point to a moveable dewlap in Draco (and other genera) that are not present in Polychrus.
Proof of a Polychrus dewlap would have to be a video of a Polychrus extending the dewlap because videos of Sceloporus quickly reveal that its an engorging (“puffing”) of the throat, so direct observation is a solid alternative to looking at the hyoid.
The taxonomy of “Polychrus” is potentially sketchy and not all species really are of that genus. Which means I also wouldn’t be surprised to see a species that has been classified Polychrus, but really isn’t related to all the Polychrus species we’ve examined the hyoids of, actually having a convincing moveable dewlap.
But at the moment, Polychrus = a moveable dewlap, all the evidence says otherwise. I also wonder whether the historical association of Polychrus as basal to anoles resulted in reaffirming wishful thinking field observations into the current myth.”
Terry’s next email made the distinction clear (as well as his unwarranted agama-philia): “If your notion of a dewlap is a prominent ornament that is dynamic in some sense (becomes extended through puffing out the hyoid in general or pushing out the CII in particular), then there are many many examples in agamids, and a handful in iguanids. I would definitely include Sceloporus, too.
If your notion of a dewlap is more specific to something that is part of a complex behaviojral display and involves rapid extension of a structure that is complex in temporal and amplitude characteristics, then it’s basically anoles, Sitana/Otocryptis, Draco and possibly one or two other agamids.
Agamids still clinch the diversity stacks in all regards – ha!”
Also not a dewlap
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