With a flurry of recent attention investigating how background light may influence the signalling efficiency of Anolis dewlaps (1,2,3,4), particularly those inhabiting low-light environments where patches of sunlight appear at a premium, it occurred to me that extended dorsal and tail crests may fall under similar selection. Below are some photos of Puerto Rican crested anoles (Anolis cristatellus) – a species in which males exhibit an enlarged tail crest and the ability to voluntarily erect impressive nuchal and dorsal crests during aggressive interactions (the mechanisms of which are detailed in this previous AA post) – that show how crests may contribute to signalling.
I have no doubt this thought has crossed the minds of many anole scientists before, particularly those current graduate students so successfully studying A. cristatellus and familiar with their ecology and behaviour (namely Alex Gunderson, Kristin Winchell, Matt McElroy, and Luisa Otero). Dewlaps are undoubtedly of primary importance to anole signalling and communication, but what are people’s general thoughts on the relative importance of other morphological features?
While out watching lizards last week with my undergraduate research assistant extraordinaire, Oliver Ljustina, and fellow SoFlo anole Ph.D. student Winter Beckles, we happened upon a pair of male crested anoles (Anolis cristatellus) ready to rumble! This is quite early – but not unheard of – in the season for the commencement of territorial disputes, so it was a surprise to see them locking horns so aggressively. This couple were battling fairly high in the tree, at approximately 3m.
I just got back from a short trip down to Eleuthera in The Bahamas where I was assisting Anthony Geneva (Harvard post-doc) in sampling lizards. Also along for the trip were Sofia Prado-Irwin (Harvard Ph.D. student) and Rich Glor (University of Kansas). We went with the main goal of sampling Anolis sagrei from four habitat types found commonly in the Bahamas as an extension of an ongoing project in the Losos lab (previous posts from: Rum Cay, Concepcion Island, Ragged Island, Bimini, Mangrove habitat, and Great Isaac Cay). Specifically, we were looking to sample Anolis sagrei in mangrove, secondary coppice forest, closed coppice forest, and beach scrub habitats. These habitats differ in the height of the canopy, density of the understory, and composition of plants.
This slideshow requires JavaScript.
We focused entirely on the southern half of the island near Rock Sound and Cape Eleuthera. We were successful in sampling two beach scrub habitats, two mature coppice forest, one secondary coppice forest, and one mangrove habitat. We were able to catch all four of the anole species found on Eleuthera: Anolis angusticeps, Anolis distichus, Anolis sagrei, and Anolis smaragdinus. We also encountered a number of other native herp species: the Bahamian boa (Chilobothrus striatus), Ameiva auberi, Eleutherodactylus rogersi, curly tailed lizards (Leiocephalus carinatus), and the Bahamian racer (Alsophis voodoo), as well as a couple of non-native species: Cuban tree frog (Osteopilus septentrionalis), and Hemidactylus mabouia.
This slideshow requires JavaScript.
In my own research I work with Anolis cristatellus, the Puerto Rican crested anole. I am always surprised when I catch A. sagrei by how much smaller they are than A. cristatellus, although very similar in appearance otherwise. On this trip, I was also surprised that the A. sagrei, as well as the A. angusticeps and the A. smaragdinus, appeared to be much smaller than those I had encountered on Bimini last spring.
We also found that the density of lizards was quite low compared to what we expected and what I had experienced in Bimini, both during the day and at night. In all four of the habitat types, we saw an abundance of hatchlings, juveniles, females, and small males, but relatively few full adult male A. sagrei. For A. angusticeps and A. smaragdinus, we encountered only a few individuals total during the week of sampling. This reminded me of an odd experience I had last fall in Puerto Rico with A. cristatellus. It was the same time of year and I had an extremely difficult time locating mature animals in sites where I had previously sampled large numbers during the spring and summer months. Instead, I observed a large number of very young animals and females. I’m curious if this is a coincidence or if perhaps there is a strong seasonal effect on either male behavior (i.e., reduced visibility outside of the mating season) or male abundance (i.e., reduced numbers because of mortality during the mating season). In other words, are the males still there, but hiding, or are they really lower in abundance in the late fall? Or maybe I was coincidentally unlucky on both trips… I am very curious to hear thoughts on this!
Anolis sagrei using coral ground habitat.
Finally, I want to end with a short natural history note on the habitat use of the A. sagrei in the mangrove habitat. In this habitat we observed A. sagrei using perches at drastically different heights: some were 6 feet up, others were on the ground. Interestingly, the ones on the ground did not appear to be in transit, but seemed to be using the pockmarked karst as perches, running into one of the many holes when approached. Has any one else observed this behavior before? It seems so different from the typical trunk-ground anole perch and behavior to me.
That’s all for now. Currently Anthony is sampling additional islands in the Bahamas along with Melissa Kemp (Harvard post-doc) and Colin Donihue (Yale Ph.D. candidate / Harvard visiting student). Best of luck to them, I can’t wait to hear how the rest of the trip went!
Over the past few years, two European research programs developed an interest in the ancient fauna and environment of the Guadeloupe islands. The prospection for cave deposits led to the discovery of numerous accumulations of fossil remains documenting the Holocene and Late Pleistocene faunas of the archipelago, especially on the island of Marie-Galante, where three major deposits were discovered.
Blanchard Cave is one of these deposits. This cave contains the oldest fossil-bearing sedimentary layers of the island dated around 40,000 years before present and is an excellent complement to the two others cave documenting the Late Pleistocene fauna of Marie-Galante (Cadet 2 and Cadet 3).
After a test excavation in 2008 that revealed the potential of the site in term of fossil fauna, Blanchard cave was investigated between 2013 and 2014 in the framework of a European research program interested in the past environment and fauna of the Guadeloupe islands, the BIVAAG project. The three excavation campaigns conducted during this period allowed the precise documentation of the sedimentary filling of the cavities and the recovering of thousands of skeletal remains mainly attributed to frogs, lizards, snakes and bats.
The excavation work in the cave (Picture: A. Lenoble)
Welcome gifts from the bats… (Picture: C. Bochaton)
But collecting the fossils remains was not that easy and although the perspective of working in the Caribbean a few hundred meters from the sea could seem very attractive, the working conditions in the cave were far from pleasant. Mainly because the cave was inhabited from the ground to the roof by numerous cockroaches, rats, gnats and bats. Bats were extremely noisy, and proved to be extremely rude hosts. Another difficulty was the potential occurrence of histoplasmosis in the cave that led to the necessity of wearing a respirator during the work. Such masks make breathing difficult during the work and combined with the heat, humidity and other disagreements previously mentioned strongly impact your initial enthusiasm.
Once you overlook these difficulties, the sediment was extracted from the site and then washed and sieved in order to retrieve the small bones contained in it (the bones are usually smaller than 5 mm). The remains were then recovered and sorted, partly in the field (unfortunately this activity often kept the paleontologists outside of the cave and away from the bats), before being studied.
Washing and sieving of the sediments (Picture: M. E. Kemp)
Recovering of the fossil bones (Picture: M. E. Kemp)
The results of the study of the squamates remains collected in the cave can be found in a very recently published paper. To summarize the main findings, we found evidence of the past occurrence of at least ten species of snakes and lizards: four snakes: Antillotyphlops sp., Boa sp., Alsophis cf. antillensis and an undetermined colubroid; and six lizards: Anolis ferreus, Iguana sp., Leiocephalus sp, Thecadactylus sp., cf. Capitellum mariagalantae and Ameiva sp.. The stratigraphic distribution of these taxa in the site combined with previously existing data show that only two extinctions (Boa sp. and Colubroid ind.) are dated from the Pleistocene/Holocene transition and thus predate the arrival of humans on the islands around 5000 years ago. Then during the pre-Columbian times two new taxa appear in the deposits, Iguana and Thecadactylus. On the other hand, a massive faunal turnover began after the European colonization of the island. Indeed, at least six squamate genera (Leiocephalus, Capitellum, Ameiva, Antillotyphlops, Alsophis and Erythrolamprus), including all the snake genera, were extirpated between 1492 and today. Thus, 55% of the squamate genera present during pre-Columbian times went extinct over the past few centuries.
These results are further evidence of the current sixth mass extinction crisis and of the strong impact of humans on this insular fauna. However, Marie-Galante Island remains an isolated case because the past fauna of most of the Lesser Antillean islands remains poorly known and in most cases totally unknown despite the critical importance that such data may have in many fields to test inferences built on modern data.
When somebody talks about roads crossing along natural forest, we could think about the perturbation this may cause to local fauna, especially in the Tropics. At least in Panama, wildlife crossings are not so popular in terms of design, deployment and monitoring. To my knowledge, the few existing ones are aerial and designed keeping in mind the crossing of monkeys or sloths for example. This issue came to my mind on the 3rd of November when I saw a Dactyloa insignis trying to cross an 8 m road traversing Santa Fe National Park, one of the pristine forest in central Panama.
Captured at Santa Fe National Park, Panama
It made three short attempts and looked clumsy when trying to run on the pavement puting him at risk of death, so we caught him and helped him reach the other side of the road.
As part of our saga chasing Anolis sagrei around the Caribbean, we had the incredible fortune to visit the remote Conception Island Bank in the Bahamas. Conception Island and its associated small satellites are situated on their own bank, adjacent to Long Island which occupies a southeastern edge of the Great Bahamas Bank. Conception Bank and all its satellite islets are protected by the Bahamas National Trust as a National Park, and the bank is presently uninhabited though there is some history of human habitation in the past. Conception Island is quite small, totaling only 9 km by 2 km and has never been connected to any other island banks, meaning that the plants and animals here have almost certainly arrived via dispersal. Though located only 25 km ENE from the northern tip of Long Island, the 2400 m deep water and strong NW currents mean that the Conception Bank has a relatively depauperate terrestrial fauna owing to the vicissitudes of over-water dispersal. For example, in the latest comprehensive list of island herpetofaunal records, Long Island boasts 16 native extant species of reptiles and amphibians, relative to just five on the Conception Bank. Granted, this is potentially owing to lower sampling effort on Conception, as it is a remote, difficult, and expensive place to conduct extensive surveys. Indeed at least one record, that of the Bahamas Boa Chilabothrus strigilatus, is poorly documented and probably spurious.
An unusual dewlap color for A. sagrei
Alberto Puente-Rolon (UIPR-Arecibo), Anthony Geneva (Glor/Losos labs), Nick Herrmann (Losos Lab), and Kevin Aviles-Rodriguez (Kolbe/Revell labs) traveled with me to the Conception Bank aboard the Golden Bear out of Stella Maris, Long Island for two days in July 2015. Our goal was to sample Anolis sagrei from the bank, as well as generally conduct herpetofaunal surveys. We were particularly interested in verifying and attempting to build upon the last report of a herpetofaunal survey there (Franz and
Male Anolis sagrei displaying a light orange/ yellow dewlap in coastal palm scrub habitat.
Buckner 1998). While we expected Anolis sagrei to be present (it was), we also thought that the lack of a record for Anolis distichus might not stand up to our surveys. Alas, we checked multiple habitat types both day and night, from beach scrub to mature forests to mangroves and failed to turn up A. distichus. Though present on nearby Rum and San Salvador Banks (as well as Long Island), this species is curiously apparently absent from Conception.
Happily, we did find Anolis sagrei in abundance, and with some unusual features to boot. For one, the largest males are really quite large, tipping the scales at over 7 grams. Many males sported tall tail crests, and in the coastal scrub habitat, their yellowish dewlaps, combined with large size and tail crests, gave them an overall appearance very similar to Puerto Rican Crested Anoles (A. cristatellus). Interestingly, dewlaps in the forest appeared more traditionally sagrei-red, so we will see what our spectrometer and photographic data tell us about dewlap color variation on the bank. We will continue to update AA on our work with A. sagrei in the Bahamas.
We have been on the move quite a bit for our project on Anolis sagrei. On a recent trip to the Bahamas, Alberto Puente-Rolon (UIPR-Arecibo) and I were able to visit the remote Great Ragged Island, located at the southeastern edge of the Great Bahamas Bank only 115 km from the coast of Cuba. Great Ragged is the only inhabited island in the Ragged Island/Jumentos Cays range, a necklace of islands stretching in a sweeping concave arc from Long Island and the southern Exumas to the range terminus at Little Ragged Island. A mere 70 or so people live on Great Ragged, concentrated in Duncan Town, a small settlement perched atop a surprisingly high hill overlooking the deep ocean to the east and dark green expanses of mangroves to the west. Duncan Town is picturesque in the authentic Bahamian sense–brightly colored houses are dotted between crumbling ruins dating back a century or more. Chickens cover yards, and old stone walls snake from the town out into the bush. An artisanal and on-demand salt raking operation continues here, and small pyramids of bleached salt dot the edges of an expansive salina filled with shallow waters reflecting varying hues of pinks and reds in the morning sunlight.
Duncan Town salina and tropical dry scrub habitat shallow waters reflecting varying hues of pinks and reds in the morning sunlight. Photo by Alberto Puente.
Anolis smaragdinus from Ragged Island. Photo by Alberto Puente
The Anolis sagrei here are, as in most locations, abundant. We had great success locating them at night, where they sleep exposed on branches and reflect a pale glow in the beam of a headlamp. We sampled anoles from different habitat types on Great Ragged, including coastal Cocolobauvifera stands, mangrove forest, stunted closed canopy tropical dry forest (where we had to crawl to make our way through), and highly disturbed goat pasture. We are excited to see how the population here compares to the rest of the range. In particular, we are wondering whether the sagrei on Great Ragged belong to the eastern or western Bahamas genetic lineage, which we have uncovered in previous work. The A. distichus here certainly resemble the populations in the western Bahamas, rather than the eastern Bahamas, to which Great Ragged is connected by the Jumentos Cays. We will follow up on these distichus observations in a later post. I will keep AA updated on what we find as we begin analysis of our data.
Assuming you can’t get your lizards to fly themselves to your lab, you might want to read this information on how to transport them home. Photo from http://www.deviantart.com/morelikethis/27371609
After years of transporting live anoles from the Caribbean to my lab in the United States in my checked luggage, this summer in the Dominican Republic, a Delta Airlines agent refused to accept our cooler full of lizards as luggage for our plane. After pursuing every avenue we could think of, it became clear that our only remaining option was to ship the lizards as cargo. We spent several days working out this process, and after making a number of mistakes, we finally arrived at a relatively smooth procedure. To prevent others from having to learn these steps on their own, if such a situation arises for other researchers, we’ve written out the steps that worked for us below. The details provided are for the airport in Santo Domingo, but this general approach may be helpful in other locations as well. (And, if you find yourself in the Dominican Republic in the near future, I’d be happy to give you the contact information for all of the folks listed below.)
I moved to Florida almost a year ago but am just now gearing up for my first, full-fledged anole deluge, typical of Florida in the spring. As the temperature rises, more and more anoles can be seen basking, mating, or, most frequently, scattering to get out from under your feet as you walk down the sidewalk! Life as an anole can be challenging, as has been documented here on AA by the likes of James Stroud and Ambika Kamath, but now that I am in the thick of anole season here in Gainesville, seeing first hand the tribulations that arise from amazingly dense populations of lizards navigating an ever-challenging urban environment, I have come to realize (and in a few cases document!) the brutal realities of life as an anole in central Florida. Below are a few of the more incredible maladies I’ve seen since moving to Florida:
A lizard who just couldn’t quite fit through the stem of a Heliconia, a fatal miscalculation.
An A. carolinensis missing his entire dewlap, possibly from a bite injury? As he ran up the tree on which I released him, I could see the lizard extending what was left of his second ceratobranchials (just under his chin), a fruitless attempt to warn me to bug off.
A brutally battered A. sagrei. This lizard was missing both eyes and his tail, two of the three injuries still bleeding when I found him, while also sporting a completely broken upper left jaw. Looks like these nasty wounds may have been sustained from a larger predator, such as a bird or pedestrian, as it seems unlikely that a lock-jaw fight between two male lizards would lead to such deadly consequences for the loser.
One component of our recent field work in Bimini, Bahamas involved gathering data from anoles across various habitat types. We selected four primary habitats for sampling based partly on the notable work by Schoener (1968): blackland forest; incipient blackland; Coccothrinax coastal scrub; and mixed Avicennia, Laguncularia, and Rhizophora mangrove forest.
Mangrove forest nocturnal survey.
South Bimini is an interesting place to study anoles in that it is a relatively small island harboring four species across at least eight different habitat types. Schoener’s excellent study of habitat use in these species indicated that mangrove forests were marginal habitat for anoles, supporting only two of the four species (A. sagrei and A. smaragdinus). During nocturnal surveys, we located both of these species roosting on Avicennia and Laguncularia leaves and branches, though in much lower numbers than other forest types. We found no anoles in Rhizophora mangle at our study site. However, we did find a number of A. angusticeps in this forest, mostly perching horizontally on Avicennia branches. We would like to know, how many others have found twig anoles in mangrove forest?
![IMG_5612[1]](https://i0.wp.com/farm2.staticflickr.com/1603/24973410511_c2eee8971f_c.jpg?resize=629%2C420&ssl=1)
![IMG_5611[1]](https://i0.wp.com/farm2.staticflickr.com/1624/24699126379_d365d22614_c.jpg?resize=629%2C420&ssl=1)
![IMG_5610[1]](https://i0.wp.com/farm2.staticflickr.com/1445/24771217750_52b54cb15e_c.jpg?resize=629%2C420&ssl=1)
![IMG_5608[1]](https://i0.wp.com/farm2.staticflickr.com/1684/25040596346_7995af2423_c.jpg?resize=629%2C420&ssl=1)
![IMG_5607[1]](https://i0.wp.com/farm2.staticflickr.com/1663/25039699926_3d94c0c11d_c.jpg?resize=629%2C420&ssl=1)
![IMG_5626[1]](https://i0.wp.com/farm2.staticflickr.com/1441/25039756456_14f5237702_c.jpg?resize=629%2C420&ssl=1)
![IMG_5616[1]](https://i0.wp.com/farm2.staticflickr.com/1595/24698893089_fb7259ab28_c.jpg?resize=629%2C420&ssl=1)
