Reconstructing the History of Anole Sex Chromosomes

Gorman_Dominica_1965_Anolis_oculatus

George Gorman in Dominica

In the 1960s and 70’s evolutionary cytogenetics experienced a remarkable burst of interest and scholarship. Thanks largely to the efforts of George Gorman (at right) and others working at the Museum of Comparative Zoology, anoles played a central role in this research (some historical detail has previously been posted on AA). Among their findings was the occurrence of heteromorphic sex chromosomes, sex chromosomes that are visibly distinguishable from each other under a microscope, in several Anolis species but not others. Furthermore, Gorman and colleagues discovered that those Anolis species with heteromorphic sex chromosomes all had male heterogamety, with some having an XX/XY system while others had an XXXX/XXY system. Chromosomes from nearly 100 Anolis species were examined during this period and about 1/3 of those species had heteromorphic sex chromosomes. Interest in chromosome evolution waned in the 1980’s as DNA sequence data became increasing accessible, but there has been a recent resurgence thanks, in part, to sex chromosomes.

Anole – Gecko Habitat Overlap

Although it may seem paradoxical given their natural history, I often see nocturnal geckos basking during the day. They usually occupy trunks between 1-3m, which is prime trunk-ground and trunk ecomorph territory. In Miami we have two of the former (A. sagrei and A. cristatellus), and one of the latter (A. distichus). Here is a photo fresh from today showing such overlap in habitat use. I have yet to see any interactions between anoles and geckos in Miami, has anyone else observed any here or elsewhere?

Brown anole Anolis sagrei and gecko (Hemidactylus sp., probably mabouia) sharing habitat space_caption

Cuban brown anole (Anolis sagrei – left) and gecko (Hemidactylus sp., most likely H. mabouia – right) sharing habitat space

Of note – this was taken 23rd Feb 2014 in south Miami (FL) at roughly 1:30pm. It’s hot and sunny.

Wet Prairie Anolis carolinensis in Two Parcels in Broward County, Florida: Historical Populations?

IMGP0471

Hi Anole Folks,

So life transported me to South Florida to beat Cancer, and looks like I have made good progress, thank you in advance. 🙂

As a general naturalist, I get out A LOT, each day- up to three hikes in different habitats.

In my area on the border of Broward and Palm Beach Counties, there are several restored Pine-Lands, some from about 1984- most  cordoned off in a way for even longer due to central farm use, cattle grazing, or logging with left over islands near the wetter areas.

I spent a lot of time in the late 70’s in Coral Gables, Florida-  with a two year stint at the U. of M.  At that time, Anolis carolinensis, while not common, could be found on buildings on Ponce de Leon Blvd. and also areas of Bird Road, LeJeune and others behind the U of M arboretum.  I also would find both A. porcatus and A. chlorocyanus at these locations.  Anolis sagrei was always in great numbers no matter what.

Returning NOW, in 2014- with extensive field searching, failed to find Anolis carolinensis. The typical haunts I’d expect–along homes, in bushes, on trees, and in scrub–failed to yield a single animal.  I put in a lot of effort.  I found A. porcatus, A. equestris, what I think is A. cristatellus, and every morph you can think of of A. sagrei.  I also found Curly Tails living sympatrically with A. sagrei in several pockets.  This I found pretty neat and worthy of some work.

Recently, while hiking a Wet Prairie, along a Cypress Marsh near a domed swamp area, I started to see a very thin green lizard perched atop grass stalks–and very often cattail stalks in the center of the wetland, over standing water.  I could not confirm the species–they were far into the swamp and their flushing distance was ASTOUNDING.   They would see me and DROP clear to the grass below.  One time I saw an individual turn brown in seconds, and disappear, not into tree branches, but into the grass on the ground! I watched this behavior 8-9 times before I knew–I had to hike into the swamp.  So I did.

IMGP0391Eventually I was able to see males and females, of what now I was sure was A. carolinensis hunting and using the grass/cattail stalks for feeding and display.  In the attached image, you will see one on cattail, and this is a typical daily encounter.  I could see five or more in a hike, on the tops of grass stalks near the seed heads.  While bushes and peripheral trees were there, they were not using this substrate. I really was seeing a marshland native Green Anole group.   And to my eyes, this group was rather “gracile” in form.  And they worked the stalks in what seemed to be a new fashion.  I even imagine–since I have not done any morphometrics yet–that their hind legs look longer, tibia/fibula and femur, and toes.  They also have  a posture for most of their time on the stalks that is not something I was used to seeing–legs held way back and tight to the body, as if to reduce their profile.  A thin Green Anole, that can hide on a grass blade :-).   The images here represent two separate anoles from two separate days.

Did the pressures of habitat loss, A. sagrei competition, and A. equestris predatory pressure, isolate this group and/or move them to this grassland habitat over water?  Could this be a recently adapted “ecomorph” which we so timely have read about?

I will be vouchering a male and female for work at the MCZ for others that might be interested.  But in the interim, my favorite interest, watching behavior, will continue.

I know all the BUTS about this- as in- are they even remnants of historical Broward animals at all?  Did they come in with the replanted slash pine and pond cypress?  I’m hoping one day by genetic work, and or even some new Xray work, we might be able to answer some of this.  And of course, in their normal historical lives, they almost certainly used this type of habitat in part.  But what about now?

That there are vigorous groups in these Wet Prairies of Broward attests to the tenacity of the species, and that it is surviving here.  And that  puts a smile on my face!!

If anyone would like additional information for research, and or visit the sites with me, please feel free to contact me at naturalist@gmail.com; I’ll be here for at least a few more months.

Would love any ideas, thoughts regarding this as well.  More photos to come as well.

Enjoy the images.

Sincerely,

Kenneth E. Barnett

IMGP0417IMGP0404IMGP0413

Ecomorphs Have Their Own Wikipedia Page

ecomorph wikipedia page

And a nice one it is! Seemingly initially created by someone in Puerto Rico. Whomever did it: well done!

Anole Tat of the Day

knight tatWhat better adornment for an arm than a lovely knight anole? Thanks to Chuck Horne, the proud bearer of this lovely crown giant. We’ve featured anole tattoos before, but there must be others out there? Anyone want to share?

A Peek Inside an Anole

Three different individuals of Anolis cybotes that appear to have small pebbles or debris in their guts.

Three different individuals of Anolis cybotes that appear to have small pebbles or debris in their guts.

While analyzing some xrays of Anolis cybotes for my thesis work, I came across a few specimens that appear to have small dark masses in their guts. The numbers are pretty low – in over 200 xrays, I can only detect these masses in a handful of individuals. My curiosity was piqued. At first glance, they look like they might be gastroliths. Gastroliths, or gizzard stones, are rocks that animals eat to aid in digestion. Basically, the rocks help manually grind the food into smaller bits in a special portion of the digestive track called the gizzard. We know that many archosaurs (crocodilians, dinosaurs [including birds], and pterosaurs) have gizzards. Dinosaur gastroliths are some of my favorite fossils because they are usually polished and quite beautiful. However, unless I’m mistaken, lepidosaurs (squamates and rhynchocephalians) don’t have gizzards and aren’t known to have gut stones. Does anyone have an idea about what this could be? It’s possible that these are just accidental ingestions of small pebbles. Anolis cybotes do often forage near or on the ground, so perhaps it’s not so far-fetched for them to pick up a little rocky debris.

Also, check out this image of a regenerated tail!

Anolis cybotes with a regenerated tail.

Anolis cybotes with a regenerated tail.

Variable Definitions in Community Ecology

Community ecology is a confusing field, confounded by the interchangeable use of many fundamental terms.

Recently, a group of graduate students and I discussed this strange paradigm and thought we would see what people’s own interpretations were.

If you have a spare 5 minutes while drinking your morning coffee, please could you fill out this short (4 question!) poll asking you to give your definition for; ‘community’, ‘assemblage’, ‘guild’ and ‘ensemble’. It will be cool to see how people’s opinions differ!

You can take the survey here!

Many thanks
James

Anole Eats Dragonfly

sagrei eating dragonfly from FB

Everyone loves a good photo of an anole eating something, and here’s a fine one of an anole chomping down on a dragonfly (or maybe a damselfly). It’s from the Facebook page of Tigertail Airboat Tours located on the Tamiami Trail in Florida. No details on what happened, but looks like a happy ending for one festive anole.

Big Dog Held at Bay by Knight Anole

dog and knight anole

 

Check out the video on this Instagram post.

New Research On Sri Lankan Horned Lizards

Lyriocephalus scutatus. Photograph by Ruchira Somaweera, National Geographic

We at Anole Annals love horned lizards, and so were delighted to read about new research on Sri Lankan hornies, reported on the National Geographic Society’s webpage. Check out the article, which details recent research by Ruchira Somaweera of Sydney University.

Certatophora stoddartii. Photograph by Ruchira Somaweera, National Geographic

Page 164 of 298

Powered by WordPress & Theme by Anders Norén