Year: 2011 Page 4 of 42

Colour Variation in Lesser Antillean Anoles

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On December 17, 2011

In Notes from the Field

Male A. oculatus, near Salisbury, Dominica

The recent post on the newly described Anolis tenorioensis, and the variation in both dewlap and body coloration in that group of species, reminded me of the striking variation in body pattern and colour in the Lesser Antillean Anolis oculatus. I was in Dominica in 2010, ostensibly to collect data on hummingbirds and Heliconias, but spent some of my free time watching the island’s only native anole. We were living in the west of the island, near the Caribbean coast and surrounded by dry scrubby forest, and here A. oculatus looked like this:

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Evolution of a Lizard Room, Part VIII: Egg Incubation

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On December 17, 2011

In Research Methods

Incubating eggs

Incubating eggs

As Dan Warner mentioned in a recent post, moisture availability is extremely important to the development and survival of anole embryos. Throughout our time breeding anoles in the lab, we have experimented with different methods of incubating eggs, including different substrates (potting soil, a mixture of soil and vermiculite, and just vermiculite), differing proportions of water and vermiculite, and supplementing substrate with water throughout incubation. We have now settled on a recipe that seems to minimize death, mould, and desiccation in our Anolis distichus eggs.

We currently start by mixing a recipe that combines 220g of vermiculite with 380g of water. According to a water potential curve for vermiculite, this mixture has a water potential of -150kPa. We then put 130g of the mix into clear small deli cups which have pre-punched holes on the side for ventilation. The clear cups make it easy to quickly monitor eggs and to spot new hatchlings. We store these cups in our lizard room at a temperature of about 29C.  As eggs get older they are gradually rotated closer to a small fan that is set on a timer to run 10 mins twice daily to increase airflow. We’ve found that the recipe we’re using does not require addition of more water during incubation.

I’ve heard and read about many different ways that people are treating anole eggs and would love if AA readers shared how they take care of their anole eggs!

Anole Annals Teams with iNaturalist

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On December 16, 2011

In Education and Anoles

iNaturalist.org is an on-line community for naturalists where you can “record what you see in nature, meet other nature lovers, and learn about the natural world.”  We’ve teamed with iNaturalist to provide a new anole-specific widget that allows our readers to see previously reported anole records and add records of their own to iNaturalist’s growing on-line database.  Check out our new Citizen Science page to give the iNaturalist widget a spin!

Anole Annals About to Hit 100,000

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On December 16, 2011

In Anole Annals Trivia

A glorious event–the 100,000th viewing of  an Anole Annals page—is about to occur. In fact, the very next page to be viewed, perhaps the first person to read these words. I should add that this is the result of 59,425 unique viewing sessions. And almost all of this viewage has occurred in the past year. Whomever’s next, let us know who you are so your name can be inscribed in the AA Hall of Fame.

Anole Annals Header Photo Contest: Round 2

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On December 16, 2011

In All Posts

This is the second round of voting for the best Anole Annals header photo.  As reported previously, the winner will receive a signed copy of Lizards in an Evolutionary Tree.  On the strength of dozens of votes from visitors arriving at our page from Mexico via Facebook , Ramon E. Martínez-Grimaldo’s photograph of A. isthmicus was the landslide winner of the first round.  Congratulations Ramon!  Next week we’ll have a final vote involving the top vote-getters to determine the winner.

Looking Out for the Little Guy

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On December 15, 2011

In New Research

A. cybotes juvenile. Photo courtesy of Thom Sanger

Apologies for the messiness of the formatting; this is my first blog post, and it only got here with a lot of technical support from JLo! History is full of examples of the little guy getting left behind. Unfortunately, so is the study of anoles. Most anole studies focus on adult lizards, and while there is certainly much to be learned from adult-focused studies, to ignore juveniles is to cheat ourselves of a great opportunity to better understand Anolis life history.

A. cybotes juvenile. Photo courtesy of Thom Sanger.

As readers of this blog likely appreciate, anoles are a model system for understanding evolution. To gain a comprehensive understanding of the factors that led to their stunning diversity, it’s important that we understand how selection acted upon these lizards at all stages of life – not just adulthood. A lizard has to survive from hatchling to reach adulthood and until we know more about how juveniles interact with their environment we cannot determine whether selection has shaped the juvenile stages with the same intensity as it has adult traits.

Thom Sanger wrote an earlier post that discussed the growth of Anolis limb length: “Growing Limbs – But Not the Kind With Leaves.” According to his post, variation in adult limb morphology can be traced “all the way back to the point in development when the cartilaginous long bone anlagen are just forming.”

This past summer, I worked with Thom, Michele Johnson (Trinity University), and Trinity undergraduates Ellee Cook and Diego Castro to study the morphology and behavior of juveniles on grounds of the Coral Sol Resort in Barahona, Dominican Republic. My goal was to understand whether juvenile lizards behave similarly to adults and whether juveniles have the same body proportions as adults.

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Anole Food Preference Experiment

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On December 15, 2011

In All Posts

As Jonathan describes in Lizards in an Evolutionary Tree (Chapter 8 ) data on anole food preferences are sparse. However, this is a critical element of anole biology that needs to be more thoroughly explored if we are going to understand the diversity of skull shapes (the topic of a future post), nutrition, or energetics in anoles. The question is simple in principle but difficult in practice: do species preferentially eat certain insects? If so, has head shape adapted for the preferential capture or mastication of insects of a particular size or hardness? Do lizards that eat insects of lower “quality” eat more often or move less often? Perhaps anoles will eat what ever bug it happens to encounter and skull diversity is the result of other selection pressures. At this time we do not yet know. Interestingly, however, preliminary evidence suggests that the primary food source of many anoles are just ants, which while quite abundant are not very nutritious. Ants can account for up to 80% of the stomach contents of A. distichus for example.

The embedded video gave me an idea for a great experiment that can be done in a controlled setting.  Simply run various bugs across the screen of an iPad and see if different species preferentially target particular sizes or shapes. If anyone would like to donate an iPad to this cause of utmost importance I would be happy to perform the experiments.

Day Time Ruminations on Knight Anoles

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On December 15, 2011

In Natural History Observations

Check out what Janson Jones has to say about the largest anole, as well as a cool video, here.

Anolis hendersoni in the Dominican Republic

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On December 15, 2011

In Natural History Observations, Notes from the Field

Here’s a close up of the Anolis hendersoni I found sleeping one fateful night inside the Dominican Republic.

Anolis hendersoni - male

Anolis hendersoni - male

Prior to finding this species, I had spent the evening looking for Sphaerodactylus armstrongi and S. streptophorus on the northern slopes of the Sierra de Bahoruco NW of Puerto Escondido.  Upon entering a patch of closed-canopy, broad-leafed forest with a dense, bushy understory, I remarked to myself, “I bet there will be Anolis bahorucoensis here.”  Anolis bahorucoensis is a bush anole that is common across the Sierra de Bahoruco, and often found alongside S. armstrongi.  I was not expecting to see A. hendersoni – another dolichocephalic bush dwelling species that is closely related to A. bahorucoensis – because it is generally considered a Haitian endemic whose range doesn’t cross the border into the Dominican Republic. When the sun set and I switched over to night hunting, I was happy to find out my intuition was, for once in my life, a close approximation of reality.

 

Anole AFLP Protocol

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On December 15, 2011

In Research Methods

The core of my dissertation involves assessing genome-wide patterns of gene flow during anole speciation. For a variety of reasons, I ultimately want to acquire DNA sequences from throughout the genome.  As a first pass, however, I’ve been using Amplified Fragment Length Polumorphisms (AFLPs).  As a molecular technique, AFLPs are experiencing a comeback of sorts [1] [2].  Popular in the early 2000’s, AFLPs went out of favor as Sanger sequencing became cheaper and easier.  The resurgence AFLPs has largely been due to the realization that evolutionary patterns often vary throughout genomes and therefore methods that survey as much of the genome as possible are preferable to those that look at one or a few regions.

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