Anole Annals

I previously mentioned this book, but through the kindness of author Karin Mesa, I can report on the contents of Oliver the Overachiever. This fine children’s book details the lifestyle of non-conforming independent thinking Oliver, who from the day of his hatching, insisted on doing things his way. Needless to say, the conservatives were against change, worrying–correctly–about the threats posed by housecats. But Oliver persevered and eventually triumphs, bringing great joy to the anole masses.

This is a fine message to send to young readers. The drawings are full of whimsy and the book is the recipient of the Mom’s Choice Awards in the category “Children’s Picture Books (Suitable For Ages Birth To 9)” and Preferred Choice Award of the Creative Toy Awards 2011. Apparently, this may be the first of many in the Oliver series and, who knows, maybe they’ll span a movie. You can learn more about Karin’s artistic diversity at her website.

Congratulations to Dr. Yoel Stuart, Ph.D.

By Jonathan Losos

On March 29, 2013

In Anoles and Anolologists in the News

Collecting data in Mosquito Lagoon. Yoel Stuart manning the helm, with Todd Campbell and Casey Gilman.

Moments ago, AA stalwart Yoel Stuart successfully defended his Ph.D. dissertation, entitled Character Displacement and Community Assembly in Anolis Lizards. The four chapters include work on species turnover in island and mainland anoles and eleutherodactylid frogs, which was published last year in Proceedings of the Royal Society of London; a review of the evidence for character displacement, just out in Trends in Ecology and Evolution; and a study on rapid evolution of character displacement, which has been discussed previously in these pages.

Let the celebrating begin! Actually, it already has.

Yoel now moves on to his postdoctoral work in Dan Bolnick‘s lab at the University of Texas in Austin, where he will be studying evolutionary divergence in the Canadian aquatic anole, Gasterosteus aculeatus. Congratulations and good luck, Yoel!

Sexual Dimorphism And Geographic Variation In A Mainland Anole

By Jonathan Losos

On March 28, 2013

In New Research

Anolis ventrimaculatus. Photo by Diego Garcés

Morphological differences between the sexes and among populations have been studied extensively in Caribbean anoles, but—like so many other aspects of biology—not so much in mainland species. Studies in the islands suggest that differences, both sexual and geographic, often represent adaptation to different conditions, either the sexes partitioning niches or populations adapting to different circumstances.

Martha Calderon and colleagues have just published a paper in Revista de Biología Tropical on variation in the Colombian anole A. ventrimaculatus. Examing museum specimens from seven populations, they find consistent size dimorphism (males larger) and substantial dimorphism in body proportions. The extent of these dimorphisms, however, varies among sites.

Unfortunately, at this time little is known about the habitat use and general ecology of this species, much less about differences among populations, so evaluation of the potential adaptive significance of this variation awaits further fieldwork.

The paper’s abstract:

Variation in body characteristics related to lizard locomotion has been poorly studied at the intraspecific level in Anolis species. Local adaptation due to habitat heterogeneity has been reported in some island species. However, studies of mainland species are particularly scarce and suggest different patterns: high variability among highland lizards and poorly differentiated populations in one Amazonian species. We characterized interpopulation variation of body size and shape in the highland Andean Anolis ventrimaculatus, an endemic species from Western Colombia. A total of 15 morphometric variables were measured in specimens from the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional, Colombia. The study included individuals from seven different highland localities. We found size and shape sexual dimorphism, both of which varied among localities. Patterns of variation in body proportions among populations were different in both males and females, suggesting that either sexual or natural selective factors are different in each locality and between sexes. Since this species exhibits a fragmented distribution in highlands, genetic divergence may also be a causal factor of the observed variation. Ecological, behavioral, additional morphological as well as phylogenetic data, may help to understand the evolutionary processes behind the geographic patterns found in this species. Rev. Biol. Trop. 61 (1): 255-262. Epub 2013 March 01.

Anolis Carolinensis/Porcatus Hybrid?

By Armando Pou

On March 27, 2013

In Notes from the Field

Old male passed over winter, tough overlord

For several years now, I have been noticing that Anolis carolinensis has been making a dramatic comeback in south Florida. In the last five years or so their numbers have exploded. Their resurgence began in the Florida Keys and they have been working their way north, recently reaching south Miami and now entering into central and northern Miami-Dade County. Unlike the original population of carolinensis, which favored rural environments, this new population is bold and holds its own against sagrei, still dominating the trunk-canopy, but ranging all across different ecological niches including completely urban environments (which carolinensis did not). However, these are simply field observations and conjecture on my part. Having said that, my theory is that they are actually a vigorous carolinensis-porcatus hybrid. I believe this not only because of their robust physical constitution when compared with the original carolinensis, but also because some within the population have the scapular ocellus normally found in porcatus while others in the same population do not and many have the white outline (like the old male in the picture), but not the inner dark portion of the ocelli and vice-versa.

Two contenders to take over turf (probably both offspring of old male). Notice one has prominent “eye-spot,” the other (victorious male) does not.

Ever Seen A Transparent Anole Egg?

By Anthony J Geneva

On March 26, 2013

In Anole Photographs

As we have posted previously, the Glor lab has been breeding anoles to assess the degree of reproductive isolation between A. distichus-clade lineages. Most eggs we collect fall into two easily separated categories: white, calcified, viable eggs; and yellow, uncalcified, inviable eggs. On occasion we get a third type: white, seemingly viable, yet uncalcified eggs. These represent only about 1% of the eggs in our current experiment. We always incubate these, in the hopes that they will develop, but typically they mold early in incubation and, upon dissection, show no signs of fertilization or development. The egg above is our first exception which, when incubated for about 3 weeks, was clearly developing (it has, sadly, since died).

So, AA community, has anyone else seen anything like this? I would very much like to hear your thoughts, interpretations and comments.

Anoles Modulate Headbob Amplitude To Maximize Detectability Based On Receiver Lizard Distance

By Jonathan Losos

On March 25, 2013

In New Research

Not effective at a great distance

Think about when you want to communicate with someone, but first you have to get their attention. Let’s start with verbal communication. If Fred is across the room, you probably holler out “Hey Fred” a lot louder than if he’s sitting next to you. Now, suppose you’re the non-verbal sort. If Fred’s a long distance away, you’re going to have to wave your hand wildly, maybe even jump up and down, to get his attention. But if he’s nearby, a little wave, even a discreet hand gesture, will suffice. Why we don’t whisper or make slight movements to attract the attention of those far away is pretty obvious–the target won’t hear or see you. But why not yell loudly or gesture emphatically even when the target is nearby (ok, we all know some annoying people who do this, but mostly people don’t)?

Signal modulation is an area of great interest in the field of animal communication, and Steinberg and Leal have just published a fascinating study on the Puerto Rican A. gundlachi in Animal Behaviour (pdf). The key to understanding signal modulation is to investigate how signal detectability changes as a function of distance. Building on prior work by Fleishman on A. sagrei, Steinberg and Leal conducted lab studies in which they move a black disk against white paper to determine how much movement is needed to attract the lizard’s attention. Fortunately, this can be easily done with lizards because they have something called the visual grasp reflex–when something gets their attention, they shift their eye to gaze right at it. Easy to determine in the lab. So, by moving the disk up-and-down different amounts and varying the distance of the lizard, the authors were able to determine the degree of amplitude of movement in the visual field most detectable by the lizards (see figure on right). Notably, there is not only a minimum visual angle, but also a maximal one, above which response declines (and then increases again; for reasons discussed in the paper, Steinberg and Leal focus on the maximal peak in the 0.25-0.75 degree range).

Of course, because the movement is expressed as an angle relative to the visual field, then as the distance to the target receiver increases, larger amplitude movements would be necessary to be detected. Moreover, looked at the other way, because there may be a degree of movement too great to maximally stimulate a response, the amplitude would be expected to decrease at shorter distances.

From North to South (Paleo-islands).

By Miguel Landestoy

On March 23, 2013

In Natural History Observations

The Hispaniolan Northern Green Anole (Anolis cholorocyanus) is a widespread species in the trunk-crown ecomorph. Its known distribution is almost entirely restricted, as the name indicates, to the north paleo-island of Hispaniola, but also includes Gonave, Tortue and Saona islands, and some portions of local “mesic” (oases) forests and hills south of Valle de Neiba, in the northern slopes of Sierra de Baoruco.

A. chlorocyanus, photographed at Jaragua National Park station in Laguna de Oviedo, Pedernales province.

The individual pictured to the left was photographed the 12th of March 2013 in a far south locality for the species, in the facilities of the Jaragua National Park, NE of Oviedo. Consulting Schwartz & Henderson 1991, and Henderson & Powell 2009, it is mentioned that its occurrence may extend into the Barahona city, which is 53 kms from the recently reported locality (Google Earth, measured as airline distance). Caribherp.com does not display it for that area in the species’ range map. Anolis chlorocyanus is a mesophilic anole as well as a human commensal, so there is the possibility that the species arrived at this disjunct locality by the transportation of construction material used to build the park’s station (several years ago), or arrived on flotsam that often washes ashore in this area of the Barahona peninsula coast (sea currents bring debris and garbage from far east). Since A. chlorocyanus‘s south island counterpart, A. coelestinus, has a restricted range through the Domincan Republic, I haven’t seen any interaction between the two, despite the fact that the latter is also a human commensal (in Pedernales and along the Barahona coast). A similar scenario could be displayed when comparing distributions of other two ecologically (tough xeric) equivalent north and south island species: A. whitemani and A. longitibialis; the former shares a similar distribution with A. chlorocyanus along the Baorucos, and seems to be limited by topographic/climate features or direct competition by its southern counterpart, A. longitibialis. I have observed both species of trunk-ground anoles independently using the same saxicolous-based subtrate in this mountain range, one in the southern (but primarily in the Barahona peninsula’s lowlands), the other in its northern slopes.

Adding some more ecological notes, A. chlorocyanus can often be observed using royal palm trees (Roystonea), usually high near the base of flower/fruit fronds, which when in blossom attract many bees and other insects.

A. chlorocyanus as typically seen in Los Haitises, in a royal palm (Roystonea). Photo taken near Caño Hondo.

How The Bearded Anole Got Its Name

By Jonathan Losos

On March 22, 2013

In Anole Art, Literature, and Humor

Anolis pogus. Photo from Wildlife of St. Martin.

The resemblance is uncanny

The diminutive A. pogus of St. Martin is sometimes referred to as the bearded anole. Since anoles lack hair, facial or otherwise, one might wonder where the name comes from. In fact, Mark Yokoyama explains on his Wildlife of St. Martin site, the name is a misnomer, a misguided translation of the specific epithet pogus. Rather than being derived from the Greek pogos, the name is a reference to the cartoon character Pogo the possum! Who else would be behind this than AA faithful Skip Lazell? Anyone have any other favorite anole scientific names?

Anoles And Other Biodiversity Of Haiti: A Calendar

By Blair Hedges

On March 20, 2013

In All Posts

Haiti has some spectacular anoles found nowhere else. For example, if you go to CaribHerp and click on “Haiti” in left toolbar, you see the 176 species of herps in the country. Then click filter by “Dactyloidae” and you see the 32 recognized anole species.

13 of those are endemic to the country, but there are quite a few in the works (not yet described). One beautiful endemic Haitian species, Anolis monticola, is on the cover of Jonathan’s book “Lizards in an evolutionary tree.” Deforestation continues, with only 1% forest cover remaining, so almost everything will be disappearing soon.

For several years I’ve been doing some intense field work in Haiti, and professional photographers have joined on the trips. In collaboration with the Audubon Society of Haiti (Philippe Bayard, president), we put together a large biodiversity calendar for this year, with text translated in 3 languages. It opens into a 24″ x 12″ poster. Anoles are on the cover and a month is mostly devoted to anoles. After some unexpected delay they have arrived and we’re happy to give them away, for cost of shipping/packing. If interested, see Caribnature for images of the calendar, and instructions to order:

Adventures With Phenacosaurus

By Jonathan Losos

On March 19, 2013

In Natural History Observations, Notes from the Field

Anolis heterodermus. Photo by J. Losos.

Although many generic names have been proposed for species within the anole clade, traditionally only three other than Anolis were widely used: Chamaeleolis, Chamaelinorops and Phenacosaurus. Each of these clades—which at one time were thought to represent early, pre-Anolis derivations from the anoline line—are morphologically distinctive. The former two, Chamaeleolis and Chamaelinorops, need no introduction—they are oddball species that at first pass might not even be recognized as anoles, and that have received a modicum of scientific study. The third clade, Phenacosaurus, by contrast, has been mostly ignored. This is surprising, because at least some species are quite notable morphologically, with head casques, heterogeneous scalation, wild colors, and an all-over prehistoric appearance. Moreover, they live at remarkably high altitudes, at least by anole standards, and have a passing resemblance—some species more than others—to Caribbean twig anoles. Nonetheless, there is almost no literature on the natural history or evolution of these anoles.

Ken Miyata’s 1983 Journal of Herpetology paper is the one exception. In it, he describes the habitat use of A. heterodermus in areas near Bogotá, Colombia. His description paints the species as one that uses narrow perches on bushes and other vegetation, and that is especially plentiful in blackberry bushes. Combined with its short legs, heterogeneous body and head scalation and elongate and compressed body, reminiscent of twig anoles like A. valencienni, one might entertain the possibility that it is in functional terms a mainland twig anole.

A year and a half ago, we reported in AA on our studies of another phenacosaur, the much smaller A. orcesi from Ecuador. Our studies conclusively demonstrated that it is in all respects like a twig anole—behaviorally, it moves extremely slow; ecologically, it is found almost entirely on narrow surfaces; and morphologically, it is a Caribbean twig anole doppelgänger. But in one respect, A. orcesi was a disappointment—it looks just like any old anole, without the wildly prehistoric aspect for which the larger phenacosaurs are renowned. For this reason, it was time to examine another phenac, and what better choice could there be than A. heterodermus, the subject of Miyata’s study, supposedly common near Bogotá, and appropriately wild in appearance?

And so Rosario Castañeda, Anthony Herrel and I converged on Bogotá in late February for just this purpose, joined by Rafael Moreno, a graduate student at Universidad Nacional de Colombia, who has just completed his masters degree research on this species, with one fine paper out and more in the works. Our plan was simple: go to appropriate spots on the outskirts of Bogotá, locate lizards in the vegetation, watch them and record habitat use and behavior, then capture them and bring them back to the field lab to measure sprinting and biting capabilities and to examine their stomach contents.