All posts by Jonathan Losos

About Jonathan Losos

Professor and Curator of Herpetology at the Museum of Comparative Zoology at Harvard University. 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.

How Anoles Sense Heat

Ahh, that warmth feels good.

We all know that many anoles species are very good at behaviorally regulating their body temperature by moving from an area that is too hot or too cold to another area that is just right. But how do they actually judge the thermal properties of a particular microsite? There’s been a lot of work on the sensation of temperature in mammals, but not so much in reptiles.

Recently, Erkin Kurganov and colleagues at the National Institutes of Natural Sciences, in Okazaki, Japan began to rectify this shortcoming, and their paper has just been published in Pflügers Archiv – European Journal of Physiology. Here’s the abstract: 

Transient receptor potential ankyrin 1 (TRPA1) is a member of the large TRP super family of ion channels and functions as a Ca2+-permeable nonselective cation channel that is activated by various noxious stimuli. TRPA1 was initially identified as a potential mediator of noxious cold stimuli in mammalian nociceptive sensory neurons, while TRPA1s from nonmammalian vertebrates (snakes, green anole lizards, and frogs) were recently reported to be activated by heat, but not cold stimulus. In this study, we examined detailed properties of the green anole TRPA1 channel (gaTRPA1) related to thermal and chemical stimulation in whole-cell and single-channel recordings. Heat activates gaTRPA1 with a temperature threshold for activation of 35.8 °C, while heat together with allyl isothiocyanate (AITC), a chemical agonist, had synergistic effects on gaTRPA1 channel activation in that either the temperature threshold or activating AITC concentration was reduced in the presence of the other stimulus. Significant heat-evoked gaTRPA1 activation was observed in the presence but not absence of extracellular Ca2+. gaTRPA1 channels were also activated by heat and AITC in excised membrane patches with an inside-out configuration. By comparing the kinetics of heat- and AITC-evoked singlechannel currents, we defined similarities and differences of gaTRPA1 channel responses to heat and AITC. We observed similar current-voltage relationship and unitary amplitudes for heat- and AITC-evoked currents and found that heat-activated currents showed shorter durations of both open and closed times. Our results suggest that the gaTRPA1 channel is directly activated by heat and chemical stimuli.

 

Help Identify Haitian Anoles

IMG_9308Ron Savage, who works for USAID and is currently posted in Haiti, reports “I haven’t been getting out herping in Haiti much since I sold my car but today I managed to go out and check out some relictual forest (at about 2,700 ft elev.) not too far from Port au Prince and photographed these two anoles. This is the first time that I’ve seen this species in Haiti or the DR come to think of it. They were both up a tree about 15-20 feet and I would say that they were both about 8-9″ long including their tails. As you can see, one has a stump tail. He was higher in the tree keeping his eye on the greener one. I honestly don’t know what these are, do you have any idea? It could actually be two species. I’m not familiar with A. ricordii, but I suppose this could be one.”

IMG_9268

Is That an Anolis porcatus in Miami?

Photo by Jake Scott

Some people think so, such as this posting on the Association of South Eastern Herpetogists website. I have my doubts about the presence of porcatus in Florida. Anolis carolinensis, after all, is derived from A. porcatus. In reality, it is simply a population of A. porcatus, perhaps smaller than most of their Cuban comrades. Suppose for some reason A. carolinensis started growing larger–wouldn’t they look like the green anoles on Cuba? Anyone have thoughts on whether Cuban porcatus are really in Florida and, if so, how easy it is to identify them?

Photo by Christopher Kirby

Here’s another putative porcatus, this one photographed by Christopher Kirby. Those heads are pretty mean looking, I’ll grant that. Several other photos are also on the ASEH website.

Lizard Olympics in Sports Illustrated 25 Years Ago Today

From the pages of Sports Illustrated, 25 years ago today

From the pages of Sports Illustrated, 25 years ago today

Sports Illustrated-2

That’s my thumb! Ain’t she a beauty?

A few months ago, I ran into Nicholas Dawidoff, the author of the fabulous new book Collision Low Crossers: A Year Inside the Turbulent World of NFL Football. Seeing Nicholas reminded me of the article he wrote for Sports Illustrated at the very dawn of his writing career, 25 years ago today. The article was on the then developing field of performance studies, measuring the sprinting, jumping, clinging and other capabilities of small ectotherms, and featuring none other than yours truly, as well as Ray Huey, Al Bennett, and Sharon Emerson. Written tongue-in-cheek, but accurately and respectfully, the article was a very nice overview of that emerging field of study. It’s worth checking out the article just to see the wacky pictures taken by the SI photographer sent out on assignment to Seattle and Berkeley.

Inexplicably, the article didn't make the cover

Inexplicably, the article didn’t make the cover

New Guide on How to Preserve Material for Genetic Studies

herp book cover

Blurb: “This guide will allow nearly everyone with an interest in amphibians and reptiles to collect and store samples for genetic analyses. It is written at a level appropriate for people with a basic background in biology, including professional scientists moving into a new project as well as wildlife managers, conservation biologists, ecologists, and others working on herpetological projects. The book should also be useful for advanced undergraduates and graduate students just starting their research careers.”

See more at the SSAR book website.

Price: $11

Aerial Behavior by Anolis pentaprion

 

 

 

 

 

 

 

 

 

Anolis pentaprion taxiing down the runway on a canopy tower at the La Selva Biological Station in Costa Rica. Photo by Vinicio Paniagua.

Anolis pentaprion taxiing down the runway on a canopy tower at the La Selva Biological Station in Costa Rica. Photo by Vinicio Paniagua.

Untitled-1Draco, the flying dragon, has borrowed an anole dewlap, so it’s only proper that anoles return the favor by developing gliding capabilities. It’s been long rumored that Anolis pentaprion, a twig anole from Central America, will launch itself off of perches in canopy and glide away, but now Steve Overbauer, Vinicio Paniagua, Craig Guyer and Mo Donnelly have documented just that in an interesting herpetological natural history note that appeared in the last issue of last year’s volume of Herp Review (Vol. 44, pp. 677-678).  Here’s what they have to say:

“Lizards with gliding or directed aerial descent behaviors are well known from the Old World Tropics (e.g., Draco, Ptychozoon), and snakes and frogs exhibiting these behaviors are found both in the Old and New World Tropics (Dudley et al. 2007. Annu. Rev. Ecol. Evol. Syst. 38:179–201). However, lizards showing directed aerial descent have not been reported from the New World Tropics. Here we report on directed aerial descent capability and behavior in Norops pentaprion, a canopy lizard from eastern Costa Rica, southern Nicaragua, and western Panama (Köhler 2010. Zootaxa 2354:1–18).

The initial discovery of this behavior in N. pentaprion was serendipitous in July 2001 when an individual was captured on a walk-up meteorological tower at canopy level (~ 25 m) at La Selva Biological Station in the Atlantic lowlands of Costa Rica. After identification, the animal was returned to the original location on the tower, but upon release to a horizontal tower brace, it executed a controlled aerial descent to a tree in the distance below. Individuals of N. pentaprion have been occasionally observed on our meteorological towers subsequent to our first observation of directed aerial descent. The lizards are typically at canopy level but are sometimes found well above the canopy on the highest levels of the towers (up to 42 m). While the typical response of N. pentaprion to the presence of personnel on the tower is to race down the tower or hide on the opposite side of vertical supports, the animals will occasionally jump from the tower to escape when approached. Since 2001 we have observed directed aerial descent by N. pentaprion from canopy towers on several occasions. In at least two instances the lizard landed at lower levels on the tower, but in other occurrences they covered substantial distance to adjacent trees including aerial rotations of near 180º. During more than one observation, animals appeared to glide with near-horizontal trajectories towards termination of the descent. Similar to some snakes, frogs, lizards, and ants showing directed aerial descent, N. pentaprion does not have strongly specialized features associated with gliding behavior such as skin flaps, skin extensions, or webbed feet. Norops pentaprion has a relatively flattened head and wide body. During aerial descent this lizard proceeds headfirst, with limbs partially extended and the body strongly flattened, a position that may take advantage of regions of relatively loose skin along the sides of the body (Guyer and Donnelly 2005. Amphibians and Reptiles of La Selva, Costa Rica, and the Caribbean Slope, Univ. California Press, Berkeley, California. 299 pp.).

At La Selva Biological Station this species is uncommon in the understory and is usually found on trees limbs. Norops pentaprion is a member of a closely-related group of anoline lizards subjected to a recent analysis of morphology and morphometrics (Köhler, op. cit.); these related taxa share similar body size characteristics with N. pentaprion and are frequently arboreal. Future observations of some of these species may result in the discovery of similar directed-aerial descent behavior. Canopy pioneer Donald Perry reported lizards with a rose dewlap parachuting between trees in the canopy in Costa Rican forests (Perry 1986. Life Above the Jungle Floor, Simon and Schuster, Inc. New York, New York. 170 pp.), but the species was not identified. In their description of Norops pentaprion, Guyer and Donnelly (op. cit.) indicated that parachuting behavior likely occurs in this species on the basis of our initial observations and those of Perry. Our repeated observations verify directed aerial descent in this species and confirm that the lizard observed by Perry was N. pentaprion, the only lizard in the region with magenta dewlap coloration.”

More Studies on Anole Chromosomes

karyotypes

When it rains, it pours. Research on the immense diversity in anole chromosomes was rampant in the 1970′s and early 1980′s, and then…nothing. Until, that is, the last two months. Not one, but two, papers appeared in Evolution, and now AA has learned of a paper on chromosomal variation in Norops clade anoles, recently published in Zoological Studies (click for a downloadable pdf). The paper, by Castiglia et al., examines karyotypes in Norops anoles and argues that karyological variation is in some cases consistent with our understanding of phylogenetic relationships within the group.

Abstract
Background: Neotropical lizards, genus Anolis (Polychrotidae), with nearly 380 species, are members of one of the most diversified genera among amniotes. Herein, we present an overview of chromosomal evolution in ‘beta’ Anolis (Norops group) as a baseline for future studies of the karyotypic evolution of anoles. We evaluated all available information concerning karyotypes of Norops, including original data on a recently described species, Anolis unilobatus. We used the phylogeny of Norops based on DNA sequence data to infer the main pattern of chromosomal evolution by means of an ancestral state analysis (ASR).

Results: We identified 11 different karyotypes, of which 9 in the species had so far been used in molecular studies. The ASR indicated that a change in the number of microchromosomes was the first evolutionary step, followed by an increase in chromosome numbers, likely due to centric fissions of macrochromosomes. The ASR also showed that in nine species, heteromorphic sex chromosomes most probably originated from six independent events.

Conclusions: We observed an overall good correspondence of some characteristics of karyotypes and species relationships. Moreover, the clade seems prone to sex chromosome diversification, and the origins of five of these heteromorphic sex chromosome variants seem to be recent as they appear at the tip nodes in the ancestral character reconstruction. Karyotypic diversification in Norops provides an opportunity to test the chromosomal speciation models and is expected to be useful in studying relationships among anole species and in identifying cryptic taxa.

How to Set Up a Lizard Room to House and Breed Anoles

Thinking of setting up a room to maintain and breed lizards for research projects? Back in 2011, the good folks in the Glor Lab–which has done a stupendous job at breeding A. distichus–shared their accumulated knowledge in an 11-part series. Given the fog of memory, it seemed like a good time to remind the world of the existence of this primer, and put the links all together in one place.

So, with no further ado, here are the 11 posts in the “Evolution of a Lizard Room” undecology:

1: Introduction

2: Maintaining humidity

3: The watering wand

4: Crickets

5: The Shopvac

6: Generating food in house

7: Egg-laying

8: Egg inculation

9: Toe clipping

10: Custom cages for breeding experiments

11: Butterfly Cages

For another source of information, check-out the manual put together by the Brodie Lab at the University of Virginia.

Nine Caribbean Skinks Petitioned for Inclusion on Endangered Species List

A while back, we reported on a monograph Hedges and Conn that described an enormous number of new skink species (35) from the Caribbean. Now efforts are being made to prevent some of these species from going extinct. The Center for Biological Diversity has just filed a petition with the U.S. Fish and Wildlife Service asking that nine Caribbean skink species be placed on the Endangered Species List. Those species are: Culebra Skink (Spondylurus culebrae), Mona Skink (Spondylurus monae), Monito Skink (Spondylurus monitae), Lesser Virgin Islands Skink (Spondylurus semitaeniatus), Virgin Islands Bronze Skink (Spondylurus sloanii), Puerto Rican Skink (Spondylurus nitidus), Greater Saint Croix Skink (Spondylurus magnacruzae), Greater Virgin Islands Skink (Spondylurus spilonotus) and Lesser Saint Croix Skink (Capitellum parvicruzae).

A press release from the CBD explains all:

“The Center for Biological Diversity filed a formal petition today seeking Endangered Species Act protection for nine newly identified species of skinks found only in Puerto Rico and the Virgin Islands. These rare lizards with smooth skins are on the knife’s edge of extinction due to introduced predators and habitat destruction. Reptiles around the globe are in the midst of an extinction crisis with roughly 1 in 5 species considered endangered or at risk of disappearing.

Puerto Rican skink
Puerto Rican skink photo © Puerto Rico Wildlife/Alfredo Colón (alfredocolon.zenfolio.com). Photos and maps are available for media use.

“Time is running out for these lizards,” said Collette Adkins Giese, a Center biologist and lawyer focused on protecting reptiles and amphibians. “The Caribbean is home to extremely rare animals found nowhere else in the world, but too many have already gone extinct. To save these skinks, we need to get them protected under the Endangered Species Act.”

Scientists recently recognized the nine petitioned skinks, along with dozens of others on Caribbean islands. The scientists initiated their study after finding unusually large genetic differences among populations of these skinks on different islands in the Caribbean. All of the newly identified endemic Caribbean skinks are near extinction (or already extinct) due to introduced predators like mongooses and cats, as well as large-scale habitat destruction for development and agriculture.

This loss is alarming because reptiles play important roles as predators and prey in their ecosystems and they’re valuable indicators of environmental health. The animals in today’s petition will reap life-saving benefits from the Endangered Species Act, which has a 99 percent success rate at staving off extinction for species under its care.

“Skinks have a slow-moving curiosity and are not adapted to fast predators such as the mongoose, introduced by humans,” said Dr. Blair Hedges of Pennsylvania State University, the lead author of the 2012 study that recognized the petitioned species. “The survival of these skinks depends on the special measures of protection that only the Endangered Species Act can provide.”

Although reptiles have been around for hundreds of millions of years and survived every major extinction period, now, due largely to human impacts, they’re dying off at up to 10,000 times the historic extinction rate. About 20 percent of reptiles in the world are endangered or vulnerable to extinction. Within the Caribbean, scientists estimate that reptiles have levels of endangerment that are at or near the highest levels worldwide.

The Center was joined in its petition for these nine skinks by Dr. Renata Platenberg, an ecologist specializing in Caribbean reptiles.

Background
The petitioned-for Caribbean skinks, which can grow to be about 8 inches long, are unique among reptiles in having reproductive systems most like humans, including a placenta and live birth. They have cylindrical bodies, and most have ill-defined necks that, together with their sinuous movements and smooth, bronze-colored skin, make them look like stubby snakes.

Four of the species for which we petitioned are found within the territory of Puerto Rico: the Culebra skink (Culebra and the adjacent islet of Culebrita), Mona skink (Mona Island), Monito skink (Monito Island) and Puerto Rican skink (Puerto Rico and several of its satellite islands). The remaining five are found in the Virgin Islands: the Greater St. Croix skink (St. Croix and its satellite Green Cay), Lesser St. Croix skink (St. Croix), Greater Virgin Islands skink (St. John and St. Thomas), Lesser Virgin Islands skinks (St. Thomas and two adjacent islets, several British Virgin Islands) and Virgin Islands bronze skink (St. Thomas and several of its islets, several British Virgin Islands).

Eight of the nine petitioned-for species fall within the genus Spondylurus, and one falls within the genus Capitellum. The genus Spondylurusincludes what are now known as the Antillean four-lined skinks because of the four major dark stripes on their back and sides. Skinks in the genus Capitellum are called the Antillean small-headed skinks and have small feet and short heads, lacking dark dorsolateral stripes.”

The entire petition can be downloaded from the CBD’s website.

Mindo Amphibian and Reptile Book Now Available in US

While on the theme of Ecuador from yesterday’s post on 25 newly described Ecuadorian herps…Word has just reached AA‘s ears that the fabulous Amphibians and Reptiles of Mindo is now available in the U.S. You can order it from Eagle Mountain Publishing, which also sells a lot of great old reptile and amphibian books at rock bottom prices.

In celebration of this great event, we’re re-printing the review posted a few months ago:

The team at Tropical Herping has done it again! This time, a fabulous, lavish, luscious, information-packed guide to the spectacular herpetofauna of Mindo Parish, Ecuador. Originally available online, the book is now available in print. I had the privilege of writing the foreword, appended below. More information is available on the TH website, as well as an order form.

Foreword:

Small in size, but a global giant in biodiversity, Ecuador is awash in all manner of fauna and flora. Birds, butterflies, trees—the country is a hotspot for just about everything. But no group of organisms is more beautiful, more charismatic, more scientifically captivating than Ecuador’s reptiles and amphibians. The Amazon rainforest dominates the attention of the public, but other parts of the country, especially the mountainous regions, are just as biologically rich. One such area is the small parish of Mindo in Pichincha Province, home to 102 species of creepy crawlies. And what an ensemble! Brilliant colors, toxic skin and venom, sweet serenades, menacing looks, gorgeous displays—this region is an encyclopedia of herpetology in just 268 square kilometers.

Field guides play an essential role in making the fauna and flora of an area widely accessible. They are at the front line of nature education and conservation, the place where the fruits of scientific exploration are distilled, synthesized, packaged, and presented to the public at large. Since the time of Roger Tory Peterson, field guides have played another role, being a venue for beautiful, yet accurate, scientific illustration, allowing readers to not only understand the identifying marks of each species, but also to appreciate them esthetically.

Despite its bountiful herpetofauna, until now no field guides existed for Ecuador’s amphibians and Reptiles. The Tropical Herping team has brilliantly stepped into this void, producing a guide to the herps of Mindo that hopefully will serve both as a model of how guides should be produced and an inspiration to the production of similar efforts elsewhere in Ecuador and beyond. The Amphibians and Reptiles of Mindo is particularly notable in three respects. First is the breadth and depth of information provided for each of Mindo’s species. These authors know their fauna in exquisite detail and have synthesized that knowledge in a clear and lucid manner. The inclusion of frog calls, recorded by the authors themselves, is an added bonus bridging the paper and digital eras. Second, the public often does not understand the connection between scientific research and the information presented in field guides, magazine articles and nature documentaries. Unlike most field guides, The Amphibians and Reptiles of Mindo makes this link crystal clear, providing citations so that readers know where to turn to learn more. Indeed, especially impressive is the fact that the authors did a great deal of field work themselves to round out knowledge of these species, presenting that information for the first time here. Finally, third, the book is simply beautiful. The photographs are simply stunning and the maps and other illustrations lovely as well.

The publication of The Amphibians and Reptiles of Mindo could not come at a better time. The Mindo region is a microcosm for all that ails the natural world. Deforestation, habitat fragmentation, pollution, overharvesting—all are threats. Mindo has one thing going for in its favor—it has become a nature vacation travel destination, providing jobs and economic rationale for preserving natural habitats. But, ecotourism can be a two-edged sword, as people and development are drawn to the area with potentially negative consequences. Mindo has the opportunity to show how responsible stewardship can be mutually beneficial to man and nature, and this lovely book shows what is at stake. Three cheers for the three authors of this magnificent volume. Long live the herpetofauna of Mindo!

Film on Haiti Herpetological Exploration to Premiere at Film Festivals

We’ve reported previously on the expedition to Haiti led by Blair Hedges of Penn State that led to the rediscovery of A. darlingtoni as well as many other important herpetological finds. Now a film about this expedition, the sad state of Haiti’s environment and efforts to protect it and its fauna is being showcased at several film festivals around the world.

Extinction in Progress premieres at the Environmental Film Festival in Washington, D.C. on March 19th and subsequently will be shown at festivals in Seoul (South Korea), Torino (Italy), Zaragoza (Spain), Goías (Brazil) and Prizren (Kosovo).

extinction in progress

Yes, that’s Anolis rupinae!