Anole Annals

Research Anoles On Eastern Cuba

On August 22, 2013

In 2007 a multi-disciplinary group (Yasel U. Alfonso, Florida Museum of Natural History, USA; Lourdes Rodriquez-Schettino, Institute of Ecology and Systematics, Cuba; and Denis Dennis Avila, Faculty of Biology, University of Havana, Cuba) began to investigate phenotypic plasticity in three Anolis jubar subspecies. We quantified variation in meristic traits, head shape, microhabitat use (i.e, escape behavior, thermoregulation, feeding) and dewlap colour to see if any of these characters differs at a geographic, and subspecies level. We analyzed variations on body dimensions and head shape (using geometric morphometrics) and their relationships with microhabitat use and found that A.j.albertscwartzi was the most differentiated subspecies (manuscript in prep.). Interestingly, Cadiz et. al. recently found Anolis jubar albertschwartzi to be more closely to Anolis homolechis than other A. jubar subspecies based on markers. The differences between our findings and genetic studies by Cadiz et al. (2013) highlight the need for a better understanding of how selective traits are shaped by speciation and selective forces.

For the last few years, our multi-disciplinary group included two new members (Humberto J. Morris, Center of Studies for Industrial Biotechnology, Cuba; and John E. Steffen, School of Science, Penn State Behrend, PA) and we have been investigating pigment patterns in anoles from Eastern Cuba. Our first approach was analyzing the dewlap colour variation among three Anolis jubar subspecies (A.j.oriens, A.j.maisiensis, and A.j.albertscwartzi) using two alternative methods: 1) digitally, using RGB analyses with Munsell’s colour system (manuscript in prep.) and 2) spectrophotometrically, using pigment concentration variation to analyze subspecies level variation in dewlap colors (manuscript available in Copeia, 2013 issue 2, “Dewlap Color Variation Based on Pterin and Carotenoid Pigments in Three Subspecies of Anolis jubar of the Cuban Southern Coast”).

This research was made throughout fall 2008 and fall 2009, and we focused on quantifying the subspecies-level flexibility in dewlap pigmentation using only biochemical compounds from dewlap skin. We found that Anolis jubar albertschwartzi was the most differentiated subspecies based on pigment concentration (see details, Fig. 1 & 2) giving a light yellow shade of his dewlap coloration.

We are performing similar pigmentary studies on several other Eastern Cuba anoles (e.g., A. allogus, A. rubribarbus, A. sagrei, A. porcus, A. anfiloquioi, A. cyanopleurus) and results will be available soon (manuscript in prep.).

In addition, I am leading other ongoing projects. One will attempt to explain relationships between color production and immune system health. Because pterins can also be synthesized by nonintegumentary tissues, most notably by immune cells (e.g. monocytes, macrophages), they may illustrate a critical link between color production and immunity in a colour-signalling system.

Finally, we’re analyzing anti-predator escape behavior, microhabitat use, and thermoregulation of anoles species on the semiarid southern coast (i.e., Guantanamo) (manuscript in prep.). All of these projects will keep us busy during next year.

Half Green, Half Brown Anole

By Jonathan Losos

On August 21, 2013

In All Posts

No, it’s not a hybrid, but why do some anoles do this? And how? Read all about it in a recent post on dust tracks on the web.

Photo by Luke Mahler.

I have noticed things like this myself. Some times when you noose a lizard, the scales underneath the noose turn dark. And so species show patterns when they are stressed that they don’t normally flaunt, like the A. garmani below. Anyone have thoughts or similar observations? Or a better photo of the phenomenon in garmani? Some images online suggest that males do this to a lesser extent when being aggressive to other males.

A. Lionotus Male Paid The Price: Snake Predation By Oxybelis

By Eric Enrique Flores De Gracia

On August 20, 2013

In Natural History Observations

[June 12 2012; 8:35 a.m.]. During a placid morning, a team from Herbios Group Panama observed an impressive image. We witnessed an Oxybelis aeneus (147 cm, 55 g) with an Anolis lionotus male (22.9 g) caught in her jaws. He was the breakfast meanwhile, his fellow female just observed the scene.

We were so happy to witness such an event, thinking about what was the male doing while the predator took the chance. Perhaps He was displaying to attract the cryptic female, or just was distracted while feeding! In any case the snake had the morning meal and the male paid the price.

Avoiding Surface Heat In Agamids And Anoles

By Ambika Kamath

On August 19, 2013

In Natural History Observations

Avid readers of this blog might have noticed that Jonathan Losos likes trying to get readers to confuse the white-fanned variant of the South Asian agamid lizard Sitana ponticeriana with the only toepad-less anole, Anolis onca. Indeed, the two lizards look quite similar:

Sitana ponticeriana, white-fanned variant, in Saswad, India

Anolis onca in Maracaibo, Venezuela. Photo by Jonathan Losos

Posts [1, 2, 3] detailing the habits and habitats of these two lizards point to a number of similarities between the species. Both occur in incredibly hot and windy environments. Both are primarily terrestrial, where they are very well-camouflaged, but are also observed perching on vegetation. The causes for the loss of A. onca’s toepads remain a mystery, and here I lay out some observations of S. ponticeriana’s behaviour that lead to a hypothesis for why A. onca might have lost it’s toepads.

Perch use in S. ponticeriana follows a predictable temporal pattern from about 8:00 a.m., when the lizards first emerge, to about 12:00 noon, the hottest part of the morning. Lizards perch primarily on rocks, if available, in the early morning while basking. During the middle of the morning, male lizards are found perching on and displaying from a variety of perches, including the ground, mud piles, rocks, twigs, and shrubs. By noon, however, lizards are often found resting in shrubs. Here are a couple of lizards resting:

Male Sitana ponticeriana, white-fanned variant, resting in the shrubs. Saswad, India.

Female Sitana ponticeriana, white-fanned variant, resting in the shrubs. Kutch, India.

But what happens when you chase lizards out of the shrubs in the heat of the day? Peak air temperatures at the site I was at this summer hovered around 40 degrees Celsius, and soil or rock surface temperatures were likely higher (they certainly felt so). Lizards that we chased out of shrubs onto the sand would run rapidly as usual, but when they paused, were often observed lifting the toes of their hind feet off the ground. Here are two photos–compare the toe positions on the hind foot to get a sense of the behaviour I’m referring to:

If the highest risk of heat exposure comes from the ground, any adaptation that reduces the transfer of heat from the ground to the lizard will be favoured. Such adaptation would explain S. ponticeriana’s behaviour of resting in vegetation during the hottest part of the day and lifting toes off the ground when forced onto hot terrestrial perches. Like most agamids, Sitana have very skinny toes, leaving a small surface area for transfer of heat from the ground. But what about A. onca? If the ancestral A. onca had typically anole-like toepads on moving to the beaches, they might have been at high risk of heat transfer from the sand when forced onto terrestrial perches in the heat of the day. This would lead to the evolution of reduced toepads to avoid such heat transfer. A temporal pattern of perch use in A. onca, similar to that of S. ponticeriana, would be the first piece of evidence useful for establishing what might be an exciting example of trans-continental convergence.

Demeaning Comments From The South

By Jonathan Losos

On August 18, 2013

In All Posts

I was communicating recently with an eminent Gondwanan herpetologist, one who has published far and wide on many issues pertaining to many species. I remarked that it was time that he/she reached the pinnacle and worked on anoles. I received this response:

“To my mind, an anole is a little like a bicycle with training wheels – quite useful for youngsters to practice on and develop their skills. But just a pale shadow of the subtlety and sophistication of real lizards. They just make it too easy to get lots of papers in good journals, and discover neat things. Where’s the challenge?”

Brown Anoles Will Display At Inanimate Objects

By Jonathan Losos

On August 17, 2013

In Natural History Observations

If I were a brown anole, I’d take offense at a flag like this, too!

Pat Shipman from the AA Little Cayman Bureau checks in:

The observation that anoles nod at inanimate objects (or possibly at anoles the observer hasn’t spotted) is not new.

A few days ago, I watched an adult male sagrei repeatedly unfurling his dewlap and displaying… at an orange landscaping flag that marks the location of a large septic pipe underground. What was most interesting is that the flag was fluttering in the breeze and that it was a shade of orange almost exactly the same as the sagrei’s dewlap. Alas, I did not have a camera handy to record this event.

Has anyone else noticed sagreis paying special attention to orange objects?

The Mystery Anole of Puerto Rico

By Jonathan Losos

On August 16, 2013

In Natural History Observations

According to Williams and Rivero, the name occultus was chosen for the anole they described in 1965 because it means “hidden,” referring to the unexpected finding of a new species in such a well-trodden spot (“The discovery of so distinct a species in an island thought to be well known herpetologically and in which the anoles have received special attention must give us pause.”). But to the unknowledgeable, “occultus” sounds more mysterious, more preternatural, befitting such a spectral, gnome-like species that is so rarely seen and so little known.

On a recent trip to western Puerto Rico, I was fortunate to visit a locality where they can be found readily at night. In a short evening, we found five clinging to the ends of twigs (as well as a dozen green giants). Naively, I thought that I’d come back during the day and locate some to see where they live when they’re active, and what they do. Ha! Much, much easier said than done. How do you find a little, camouflaged gray match-stick of a lizard in the dense vegetational matrix that is a tropical forest? The answer: you don’t, and I didn’t.

I’m thirsty! Photo by J. Losos. For more on drinking occultus, check out Manuel Leal’s recent post on Chipojolab.

Indeed, there are almost no data on the natural history of this species, except where it sleeps. The little that we do know suggests that they are just what they look like–twig anoles. Some of the few that have been found have been on twigs, though a surprising several have been on leaves or ferns. They seem to creep slowly, though no one has published a good behavioral description.

Photo by J. Losos

Since the description of this species in 1965, there has only been one paper written on the diurnal natural history of this species, published by Preston Webster in 1969–44 years ago (go ahead, read it yourself)! Someone needs to go out and find these guys and see what they do! How to do it? Go find them at night and come back before dawn and watch them as they wake up and get out of bed. And here’s a bonus–George Gorman published a paper suggesting they sleep in pairs–that’s right, pair-bonding twig anoles!

Note that these photos were taken of animals captured and placed on twigs, as was the lizard which subsequently started drinking raindrops discussed on Chipojolab.

And here’s one acting like a real twig anole. Photo by J. Losos.

Effect Of Brown Anoles On Behavior And Habitat Use Of Green Anoles

By Jonathan Losos

On August 15, 2013

In New Research

Up high displaying green anole. Photo from this website, which has some nice other reptile shots.

Many animals use different parts of their habitat for different activities–eating in one place, mating in another, and so on. This hasn’t been studied in many anoles, but has been documented in several. In addition, many species alter their habitat use in the presence of competitors, and this has been widely demonstrated in anoles. However, few have studied the interaction of the two phenomena: is the extent of behavioral partitioning among habitats affected by the presence of competitors?

To address this question, Ambika Kamath and colleagues studied green anoles on several islands in Mosquito Lagoon in the Intracoastal Waterway of Florida. In this area, a number of small “spoil” islands were created when the waterway was dredged half a century ago. These islands were quickly colonized by plants–and now are covered with very large trees–and then by green anoles. More recently, the invasive brown anoles have arrived on the scene on some of the islands.

Kamath et al., whose research was recently published in a paper in Breviora, chose four islands, two with brown anoles, two without (freely available, as are all MCZ publications, on the museum’s website). On these islands, they recorded habitat use and behavior. As predicted animals forage at lower heights than where they perch. One possible explanation is that they sit at vantage points looking for prey, then go down and catch them. And as predicted, males display at particularly high spots. The explanation here is not clear, but as reported recently for A. cuvieri, males seem to like to display higher than their rivals. Finally, once more as predicted, in the presence of brown anoles, green anoles shift upwards in all respects.

The interesting finding, however, is that the shift is essentially parallel for all activities. Animals move downward the same amount to capture prey and upward the same amount to display. This would suggest that there is not an optimal height for feeding or displaying, or perhaps that the optimal height changes in the presence of brown anoles. That would be readily understandable with regard to feeding–the voracious brown anoles probably vacuum up the low-lying food, so no point in dropping down as low to feed as in their absence. Why males continue to move up even higher is less obvious, though it may be just that competitors are now perching higher, so a male has to go higher yet to display above them.

This paper represents the sort of detailed behavioral study that is all too infrequent for anoles. How these lizards modulate their behavior in response to conditions is fascinating and often surprising. Much remains to be learned, and most anole species–well, at least in the Caribbean–are amenable to behavioral observation.

Ol’ Blue Eyes: Convergence In Frank Sinatra And Anoles

By Jonathan Losos

On August 14, 2013

In Natural History Observations

Anolis stratulus

Anolis evermanni

Anolis gundlachi

Ok, this post has nothing to do with Frank Sinatra other than his nickname. But what about blue eyes in anoles? They seem to pop up all over anole phylogeny. For example, in my recent trip to Puerto Rico, three anoles had cerulean peepers–A. evermanni and A. stratulus, which are closely related, and A. gundlachi, which is more phylogenetically distant. And blue eyes occur in other anoles, such as A. etheridgei from Hispaniola.

The observation raises two questions:

1) Just how phylogenetically widespread is the occurrence of blue eyes in anoles? I know I’ve noted blue-eyedness from time to time, but I haven’t get tracked and can’t remember in which species. I propose the Anole Annals community take it upon itself to compile a list of blue-eyed anoles. If you know of one, please post a comment and, even better, add a photo.

2) Why? I can’t believe there is an adaptive significance to having blue eyes per se. Is it genetically linked to some other adaptive trait? Could sexual selection have a role (though I don’t know of sexual dichromatism in eye color)? Other animals exhibit interspecific variation in eye color and I bet there’s a literature trying to explain it, but I’m not familiar with it. Would make an interesting project!

Some quick googling reminded me of a few other examples, below. Who am I missing? And does anyone have a good photo of blue-eyed etheridgei?

Anolis transversalis

Anolis peraccae

Anolis oculatus

Name That Big Costa Rican Anole

By Jonathan Losos

On August 13, 2013

In Notes from the Field

Rick Stanley photo #2 of a large Costa Rican anole

Award-winning nature photographer, naturalist, and undergraduate Rick Stanley spied this large anole in Costa Rica. Is it A. microtus? A. insignis? Something else?

Photo #1

Here’s what Rick had to say: “I encountered these impressive lizards on the Pacific Slope of the Cordillera Talamanca, on the border of Chirripo National Park, in the summer (wet season). They were between 1500 and 1600m elevation, in secondary forest habitat. Although sightings were about a month apart, all of the animals observed were in the same general area near the cabins.

Photo #3

Images 2/3 are of the same individual. Image 1 was taken nearby at an earlier date, so it could be the same individual as well. Image 4 is of a different, slightly smaller individual seen along with 2/3 (perhaps the female?). The male(?) displayed his dewlap at me- I think it was an aggressive gesture, because the female was out of sight by then. When I first saw him, he had a large clump of moss in his mouth that he proceeded to devour (chances are there was an insect in there as well).

Photo #4

The lizards were over a foot long including the tail, although I didn’t catch them and measure svl. The first time I sighted 1 it was sunning. Later, it changed color and appeared more like the individual in photos 2 and 3. Didn’t move much, as I found him in the same place the next day, hanging head down on some vines.

There is also some damage to the animal’s dewlap that isn’t part of the pattern.”