Author: Jonathan Losos Page 88 of 133

Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.

Anolis sagrei nelsoni from Little Swan Island. Photo by Steve Busack.

Yesterday I wrote about our upcoming trip to look for the giant brown anole, A. sagrei nelsoni (and other reptiles), in the Swan Islands of Honduras. To give a little flavor of what we have in store, here are two mini-reports from trips here in the 1970’s.

First, Steve Busack’s reminiscences from a Smithsonian sponsored expedition 40 years ago:

Swan Islands iguana. Photo from http://www.tarleton.edu/Faculty/dekeith/iguana2.jpg

“Wow! It was so long ago, and my memory—aside from some pretty interesting aquatic (diving) iguanas at the dock around dusk—doesn’t recall very much. And I’m afraid that my experience with Anolis in the field is less than bountiful. I could help much more if it were Podarcis on Swan Island.

If I were given an opportunity to return, I’d have to think twice. BUT there is one issue I’ve always wanted to address if I had the opportunity. Great Swan was—at that time—”loaded” with worm snakes (Leptotyphlops if I recall correctly). One evening we took a handful (probably about 20 or so) and placed them in a chest type freezer available at the NOAA main building. After we had dinner, we returned to the dormitory and removed the specimens from the freezer. They were all frozen. We placed them on a bed in the dormitory while we worked with other specimens — allowing them to thaw before we preserved them. Several specimens actually thawed out and begain crawling off the bed. I was amazed!! A tropical snake with the ability to become frozen to the point that it is quite stiff—truly a surprising result. Because the island was accessible only by flying over from San Jose on a NOAA “supply flight,” and at the time I had no access to anything physiological, I dropped the idea of pursuing it further—thinking others I mentioned this to would have better access. To my knowledge, nobody has investigated survival of these snakes after freezing, or—more interesting—the physiological pathway they have available allowing such resistance.

One hint: if you decide to go, and wish to visit Little Swan as well, bear in mind that Little Swan is uninhabited and it’s basically a rock in the water with no fresh water. We had a tent with us, and air mattresses, but finding a place to sleep wasn’t easy. Also the island is full of the mites that infect sea birds—and people. I am not generally allergic to insect bites, but these mites sent me to an ocean bath one morning. I can’t remember if DEET was available back then, but I’d highly recommend it now. As I recall we stayed only one night on the island (radio contact and transport with the main island thanks to NOAA personnel).”

And Brad Lister, whose work I summarized yesterday, recollects:

“I do remember Swan Island and the giant sagrei very well (or is it nelsoni now?). Of all the places I’ve been, Swan seemed the most remote and enchanted.

It was the summer of 1972 and I was on the last leg of a trip to Jamaica and the Cayman Islands. NOAA had a weather station on the island and they flew me in and out. The CIA had used Swan as a staging area for the Bay of Pigs and had created a landing strip that destroyed maybe 1/4 of the forest. Apparently the island was also used for a coconut plantation at one time. At least the time I was there, the remaining forest was fairly open with a low (<10m) canopy, mainly small (10-20cm trunk diam) trees, with lots of small palms in the understory. The sagrei were fairly abundant, but not really dense. Not sure what predators might have been on the island back then, but I did see a several feral cats. I did not see any other reptiles except the big iguanas, though as I’m sure you know, Aristelliger nelsoni is listed as a resident.

Qualitatively, the anoles certainly looked like your average, every day sagrei scaled up to a larger size. Nothing striking morphologically that would distinguish them from the basic sagrei body plan. I remember being somewhat disappointed that they hadn’t evolved a more exotic look given how isolated the island is, and having just left Little Cayman and being so impressed by the really cool A. maynardi. Then again, I just measured SVLs & head size, counted lamellae, and did some other basic scale counts. In retrospect, it would certainly be interesting to get an estimate of how long the population has been on Swan and to look for the the adaptations that have been identified in solitary anoles that are utilizing a broader range of perch sites. My guess is that the large size is primarily due to competition for females, and would expect the males to spend the lion’s share of their time courting and defending their territories. Little Swan island intrigued me, but there were no small boats so I was never able to land and explore. Amazingly enough it had a species of hutia that went extinct sometime in the 1930s(?).”

The endemic and extinct hutia of Little Swan. Photo from http://www.redorbit.com/media/uploads/2004/10/42_8cf650ddccd939f96fdf01fb8572efa0.jpg

Expedition To Swan Island: In Quest Of The Giant Brown Anole

By Jonathan Losos

On December 1, 2012

In Notes from the Field

Great Swan Island. Image from http://4.bp.blogspot.com/-r2giIJn_MqU/TinmSdNEWgI/AAAAAAAAHYU/m4CSy8_7NU8/s640/An+aerial+view+of+the+eastern-end+of+Swan+Island+..jpg

The Swan Islands are a tiny specklesome trio stuck in the middle of the Gulf of Mexico. Great Swan, picture above, is scarcely two square males in area; Little Swan to its east is smaller yet and Booby Cay barely deserves mention.

The islands have an interesting history. Christopher Columbus is said to have stopped there to collect wood, for which reason Honduras, as the last vestige of the Spanish Empire in the New World, claimed it as its own. However, the U.S. also claimed the islands based on a visit there by a sailor in the mid-19th Century. In the middle of the last century, the U.S. operated a weather station there, and in 1960, a radio transmitter was put into place to beam Spanish language propaganda into Cuba; Radio Swan gained attention as it operated before and during the Bay of Pigs invasion. At that time, there were 28 inhabitants of Great Swan, possibly an all-time high. The radio station was removed in the late 1960’s, and in 1972, the U.S. relinquished control to Honduras, and now the island is home to a small Honduran naval garrison. In 1988, Hurricane Mitch devastated the island.

From photographs, the island seems pretty typical of many in the Caribbean; scrubby and somewhat xeric, with some palm trees. One curiosity is that almost the entire length of the island is bisected by an airstrip, presumably put in by the US during the halcyon days of the 60’s and 70’s. Little Swan island has a much different aspect, with karst rock formations and covered with cacti.

So, who cares?

Florida Bark Anoles

By Jonathan Losos

On December 1, 2012

In All Posts

From dust tracks on the web.

Janson Jones is on another mini-anole tear over at dust tracks on the web. Today–distichus. Yesterday–sagrei. He’s threatening to switch to snakes. Head over there and demand he run the Floridian anole gamut!

Put A Large Graphic Anole On Your Wall

By Jonathan Losos

On November 30, 2012

In Anoles in Commerce

Picture this on your wall! You can buy this enormous anole graphic and put it wherever you want. The 52″ version is less than $60. Interestingly, this is the same image that was in the book Snakes and Reptiles: The Scariest Cold-Blooded Creatures on Earth, which I reviewed a year ago and which was panned by several commenters.

More On Mexican Anoles: Gunther Sinks Guentheri

By Jonathan Losos

On November 29, 2012

In New Research

We recently posted the lovely guide to Mexican anoles prepared by Gray et al., which featured photographs of 46 species and attracted a lot of attention. Close on its heels comes a new paper in Zootaxa by Gunther Köhler who examines two little known species, A. cumingii and A. guentherii, each known from a single specimen. To make a not very long story short, Köhler examined the type (and only) specimens of both species and concluded that neither is a valid species: cumingii is sunk within A. sericeus and guentherii into the Jamaican A. grahami. In the latter case, it is much more likely that the type locality of “Mexique” for the 1870’s vintage specimen is incorrect than the alternative, that a population of grahami occurs somewhere in Mexico.

This would seem to be a major setback in Anolis’s inexorable climb to the 400 species plateau (put most recently at 386 in a paper I read). Fear not, though—these species have been so poorly known that they were not included in most species listings, including the Gray et al. poster (except A. forbesi).

Köhler concludes by noting that there are a number of other extremely little-known Mexican species requiring further examination, concluding: “However, there are still several nominal species associated with the anoline herpetofauna of Mexico that are of uncertain status, such as Anolis adleri Smith 1972, A. damulus Cope 1864, A. forbesi Smith and Van Gelder 1955, and A. simmonsi Holman 1964. I agree with Lieb (2001) that, as has been the case with the two species treated in the present paper, some, if not the majority, of these enigmatic taxa will be shown to be synonyms of well-known species.” As mentioned, A. forbesi is illustrated in Gray et al.’s guide, and they note that they intend to sink adleri and simmonsi into other species.

Brown Anole Snacks On A Moth

By Jonathan Losos

On November 28, 2012

In Anole Photographs

Stephanie Zembillas, who posted this photo on Twitter and another on Tumblr, had this to say: “I wanted a picture of a moth, but an anole wanted lunch. We made a compromise.”

Genetic And Morphological Divergence In Anolis Roquet: Roles Of Ecological Differences And Historic Isolation

By Jonathan Losos

On November 26, 2012

In New Research

For a number of years, Roger Thorpe and colleagues have been studying patterns of geographic variation in Anolis roquet on the island of Martinique. This species is famous–along with A. marmoratus on Guadeloupe to the north–for the tremendous amount of phenotypic variation that occurs on a relatively large island, so great that Skip Lazell described six subspecies of A. roquet. The photo above illustrates how different looking these populations can be.

Martinique is an unusual island, unique in the Caribbean as far as I’m aware, in that it is an amalgam of several different islands that were distinct for millions of years before being united by a volcanic eruption that poured out lava that connected them. Previous work has shown that there is still a clear genetic signature of this historic isolation, with different lineages occupying their ancient homelands. In addition, Martinique harbors considerable environmental heterogeneity, from sealevel to the 1400 meter peak of Mount Pelée. Much of the mountainous area is cloaked in rainforest, whereas in the rainshadow of the mountains, the environment is quite dry.

This situation has allowed Thorpe and colleagues to ask: which drives divergence more, historic isolation (i.e., allopatry) or the divergent selection pressures that occur in different environments? To examine this question, they have sampled along transects that either cross the boundaries where two lineages meet or that cross environmental transition zones within a single lineage. These transects are exhibited in the figure above–the white lines are the separation among the lineages, the background color represents the environment, and the red lines are the transects (note that the transects cross the lineage boundary at one end, but those sites were excluded from the analysis). Across these transects, the authors measured genetic and morphological differentiation, the latter by examining body patterning and the color of the dewlap and body, as well as limb dimensions and scalation.

The results reported in their most recent paper show that both isolation and environmental differences can lead to divergence, though more predictably so for the latter.

25% Off On 2013 Anole Calendar Today

By Jonathan Losos

On November 24, 2012

In All Posts

Go to Zazzle’s webpage for the calendar.

Use special code: ZSUPERSALE4U

Cold-Blooded Cuba: An Awesome Video Starring Anolis LIzards

By Jonathan Losos

On November 24, 2012

In Anole Art, Literature, and Humor

httpv://www.youtube.com/watch?v=fuqhUd6vHcA&list=PL7929B6ECB1A26675&index=1&feature=plpp_video

This fabulous video documents the evolutionary diversity of anoles and Eleutherodactylus frogs on Cuba. All of your favorites are here: swimming vermiculatus, chipojos (Chamaeleolis), a diversity of dewlapping delights (mestrei! allogus!), even a brief glimpse of a bartschi. The Irish-accented narration is quite good–and set to a lovely soundtrack–explaining in mostly accurate terms how anoles and frogs colonized and diversified in Cuba. Hats off to producer Tom Greenhalgh!

Astute AA readers may remember that we featured another video on Cuban anoles recently, as well as the splendid work in Miami by Day’s Edge Production. Sounds like it’s time for an anole film festival (a la the insect video contest just reported in the New York Times)! Plenty of islands still available for you aspiring documentarians.

Green Anole Stalking And Capturing A Butterfly: The Story In Photos

By Jonathan Losos

On November 20, 2012

In Natural History Observations

We’ve talked about anole predation on butterflies before, and now Karen Cusick has photo-documented the events leading up to it on Daffodil’s Photo Blog. This is the same green anole that Karen previously documented with an enormous moth in its mouth.

The moment before the attack was launched.