Sunday, May 27, 2012

Early 20th Century Attempts to Conserve Komodo Dragons

The idea of conservation can be found in early religious and philosophical writings. There are examples in many ancient religions. In ancient Greece Plato lamented the degradation of pasture land. In the bible, God commanded Mosses to let the land rest from cultivation every seventh year. Prior to 18th century European cultures frequently considered admiration of nature to be a pagan view, wilderness was denigrated while agriculture was praised. By the mid-19th century conservation became popular as ecological knowledge spread. 

In 1912, Dutch scientists announced the existence of large lizards on Komodo Island in the Dutch East Indies. In September 1926, the Burden expedition from the American Museum of Natural History, returned from the Netherlands East Indies (now Indonesia) with two huge, live monitor lizards that became known as Komodo dragons. Burden's specimens were placed on display at the Bronx Zoo where they drew large crowds - 38,000 visitors on 12 September. But, the lizards survived only a few short months in New York City, both were dead by mid-November. However, the publicity and crowds generated during their  short stay at the zoo turned them into a “celebrity species.” 

Timothy Barnard at the National University of Singapore has written an article that focuses on Dutch attempts to limit access to the dragons. The profits and publicity generated by Burden's Komodo dragons in scientific institutions could not be ignored. Dutch officials now had to deal with numerous requests for Komodo dragons. The applications for collecting dragons were submitted to a colonial administrative system that aspired to rationalize Dutch rule over vast areas of the archipelago and to make the Netherlands East Indies a center of scientific research and conservation.

Dutch officials’ reacted to requests, with a number of regulations to deal with the developing circumstances. The resulting rules and procedures became part of larger global trends related to emerging environmental consciousness, while also reflecting understandings of how to create a system of control over distant lands and nature. Foreigners seeking a Komodo dragon would usually be directed to the Department of Agriculture, located in Buitenzorg. Barnard chronicles the early history of Varanus komodoensis in western zoos, but perhaps of more interest are the rules and regulations the Dutch instituted, rules and regulations that placed the colonly Dutch at odds with the indigenous people. The Ordinance to Protect Certain Mammals and Birds covered all wild animals, except those designated by the governor-general and those considered to be pests. The exclusion of pests weakened the ordinance, because pests included all monkeys, the orangutan, and a number of other species traditionally hunted throughout the archipelago. The ordinance was also weakened because it was only applicable in Java and a few other scattered parts of the Dutch colony, hunting rights in the rest of the archipelago was left up to 280 indigenous rulers, including the Sultan of Bima in eastern Sumbawa, who had traditional rights over Komodo and Rinca. later the law was altered and applied so that it could protect the dragons and increased tensions between the colonial government and the local peoples. Eventually the regulations were changed to protect a relatively few species, and the dragon was given added protection by the establishment of a reserve.

Barnard discusses several scientific expeditions intent on collecting dragons, including the thwarted attempt of the Crane Expedition that included Karl P. Schmidt from the Field Museum, and the competing Chancellor-Stuart Expedition that was eventually successful in obtaining two of the lizards for FMNH using a cooperation and diplomacy.

Citation
Barnard, T.P. 2011. Protecting the Dragon: Dutch Attempts at limiting Access to Komodo Lizards in the 1920s and 1930s. Indonesia 92:97-124.


Friday, May 25, 2012

Turtles are the Sister to the Archosaurs

An archosaur feeding on a turtle. JCM
The evolutionary origin of turtles is one of the last unanswered questions in vertebrate evolution. Paleontological and morphological studies place turtles as either evolving from the ancestor of all reptiles or as evolving from the ancestor of snakes, lizards, and tuataras. Conflictingly, genetic studies place turtles as evolving from the ancestor of crocodilians and birds.

Having recently looked at more than a thousand of the least-changed regions in the genomes of turtles and their closest relatives, a team of Boston University researchers has confirmed that turtles are most closely related to crocodilians and birds rather than to lizards, snakes, and tuataras.

The researchers published their findings in the Royal Society journal Biology Letters. By showing that turtles are closer relatives to crocodiles and birds (archosaurs) than lizards, snakes and tuatara (lepidosaurs), the study challenges previous anatomical and paleontological assessments. Nick Crawford, a post-graduate researcher in biology in BU's Graduate School of Arts & Sciences and lead author of the study, achieved these findings by using computational analysis to examine regions of the different animals' genomes.

"Turtles have been an enigmatic vertebrate group for a long time and morphological studies placed them as either most closely related to the ancestral reptiles, that diverged early in the reptile evolutionary tree, or as closer to lizards, snakes, and tuataras," says Crawford.

The study is the first genomic-scale analysis addressing the phylogenetic position of turtles, using over 1000 loci from representatives of all major reptile lineages including tuatara (lizard-like reptiles found only in New Zealand). Earlier studies of morphological traits positioned turtles at the base of the reptile tree with lizards, snakes and tuatara (lepidosaurs), whereas molecular analyses typically allied turtles with crocodiles and birds (archosaurs).

The BU researchers challenged a recent analysis of shared microRNA families that suggested turtles are more closely related to lepidosaurs. They did this with data from many single-copy nuclear loci dispersed throughout the genome, using sequence capture, high-throughput sequencing and published genomes to obtain sequences from 1145 ultraconserved elements (UCEs) and their variable flanking DNA. The resulting phylogeny provides overwhelming support for the hypothesis that turtles evolved from a common ancestor of birds and crocodilians, rejecting the hypothesized relationship between turtles and lepidosaurs.

The researchers used UCEs because they are easily aligned portions of extremely divergent genomes, allowing many loci to be interrogated across evolutionary timescales, and because sequence variability within UCEs increases with distance from the core of the targeted UCE, suggesting that phylogenetically informative content in flanking regions can inform hypotheses spanning different evolutionary timescales. The combination of taxonomic sampling, the genome-wide scale of the sampling and the robust results obtained, regardless of analytical method, indicates that the turtle-archosaur relationship is unlikely to be caused by long-branch attraction or other analytical artefacts.

The BU study is the first to produce a well-resolved reptile tree that includes the tuatara and multiple loci, and also is the first to investigate the placement of turtles within reptiles using a genomic-scale analysis of single-copy DNA sequences and a complete sampling of the major relevant evolutionary lineages. Because UCEs are conserved across most vertebrate groups and found in groups including yeast and insects, this framework is generalizable beyond this study and relevant to resolving ancient phylogenetic enigmas throughout the tree of life. This approach to high throughput phylogenomics -- based on thousands of loci -- is likely to fundamentally change the way that systematists gather and analyse data.

N. G. Crawford, B. C. Faircloth, J. E. McCormack, R. T. Brumfield, K. Winker, T. C. Glenn. More than 1000 ultraconserved elements provide evidence that turtles are the sister group of archosaurs. Biology Letters, 2012; DOI: 10.1098/rsbl.2012.0331

Suzio Repiort - Some Weird Molossus Shots


Howdy Herpers, 05/24/12

I've been slowly but surely digitizing some of my 35mm images. What's the point in doing that if I can't bore you all to tears with some of them?

I'm too lazy to go back to my notes, but I'm going to guess that it was in July of 2000 that the most unusual road cruising event I've ever witnessed occurred. We were in two cars. Gery Herrmann and Ralph Shepstone were in one, Mike Dloogatch, Steve Barten and I were in the other. As we were driving roads that were on the reservation, I insisted that we leave all our collecting equipment at home. Tribal laws are strange, and I didn't want us to get in trouble.

At one point in the evening, we pulled abreast of Gery and Ralph, who were busily jacking their car up whilst giggling like little school girls. We of course inquired if they had a flat tire, to which they sheepishly responded "no." It took a while to drag it out of them, but the short story is this:

They pulled along side a black-tailed rattlesnake (Crotalus molossus) to admire it. The snake darted toward the vehicle. As they had no tongs or hooks, they could only watch helplessly while the snake methodically crawled into the rim of their rear passenger tire. At the point that we arrived, the snake was not visible. But soon after, it shot out of the rim. Only Steve was quick enough with his camera to get the image of the snake coming out. Steve is one of the best photographers I know, but there was no time for anything fancy.

The first image in this report is all that Steve got--but I'm glad that he got that much!

How many of you have ever caught a rattlesnake with a tire?

Before I launch into the rest of images in this report, I want to ask you herptographers out there to participate in something I'm going to do with an upcoming Suizo Report. I want to gather images of molossus from all the various mountain ranges, and compare them. I'm looking for the prettiest, as well as the most dog ugly. In the end, we will decide where they are the most beautiful, and where they are not. But no matter WHAT they look like, they are still, in my opinion, ALWAYS a good find.

Now, to the pics:

Image 1: Already discussed, by Steve Barten.
Image 2: This scrawny, miserable looking molossus was found in Saguaro National Park West. It was found on 25 July, 1997--at the end of what at the time was the 2nd worst drought in weather history. (The droughts that followed this one in the Y2K century made the drought of '97 seem like kissing a pretty woman). The more I look at this image, the more I think this is a female snake that has dropped a litter. But as my notes indicate that it was blind in one eye, it could just be a snake that was in severe decline. The real reason I've slipped this one in is the color. Very weird for a low elevation molossus.
Image 3: Found in Sabino Canyon on 21 July, 1994, this one has the most pronounced atrox-like tail banding that I've ever seen. I'd LOVE to see anything like this from some of you.
Image 4: From Saguaro National Park West, found 16 July 2000. Note the posture of this snake--almost like it is constricting a prey item. The reason for the posture MAY be because it was infested with sand flies. Said flies seem to be absent in the image, so I'm guessing they all flew away during the photo session.
Image 5: By Dan Bell. No, we don't go around throwing rattlesnakes on prickly pear. We watched in amazement while this molossus crawl to the top of this prickly pear cactus THREE TIMES! It seemed to be hot on the trail of a prey item. It would crawl around the base of the cactus, go to the top, and come back down. We watched this for about an hour before growing bored of it and moving on. Snakes are amazingly patient hunters!
That's all for this one. Remember, I'm hoping to get some images from you that you are willing to share. Ugly, pretty, they are all VERY COOL rattlesnakes.

This here is roger repp, signing off from burning hot Arizona, where the turtles are strong, the snakes are handsome, and the lizards are all above average.

Thursday, May 24, 2012

CBD Threatens to Sue USFW Over Herps


Graptemys barbouri

ATLANTA -- An environmental group threatened Tuesday to sue the U.S. Fish and Wildlife Service for not moving quickly enough to protect 25 amphibian and reptile species across the Southeast that it believes are in danger of extinction.
Officials at the Minneapolis-based Center for Biological Diversity said they hoped the threat of a lawsuit would prod federal officials into taking action.
"The amphibians and reptiles named in this notice need the protections of the Endangered Species Act to survive," said Collette Adkins Giese, an attorney for the center, and D. Noah Greenwald, its endangered species program director, in a letter. "Turtles, salamanders, snakes and other species of herpetofauna are some of the most rapidly disappearing species on Earth."
In 2010, the center and other supporters filed a petition seeking enhanced protection for more than 400 aquatic species in the southeast under the Endangered Species Act. During a 90-day review, federal officials found there was information to believe that more protection may be warranted for 374 of those species, including the 25 amphibians and reptiles that were the focus of Tuesday's letter.
It accused the government of failing to make a follow-up finding for those species that was due on April 20, 2011. The species listed in the complaint live in wetlands across the Southeast. The Barbour's map turtle, for example, can be found in the Apalachicola River system that flows through Georgia, Alabama and Florida. The center contends it is threatened by collection, dredging, pollution and disease.
Another example is the seepage salamander, which lives in Alabama, Georgia, North Carolina, South Carolina and Tennessee. The center said the seepage salamander population has been halved by logging and other activities that destroy its habitat.
Fish and Wildlife Service spokesman Tom MacKenzie said he could not immediately comment on the lawsuit threat.



Tuesday, May 22, 2012

Diasporus citrinobapheus, a New Frog from Panama


A new bright yellow frog species has been found in the mountains of western Panama. The frog belongs to a species-rich group of frogs, the so called rainfrogs that lack a tadpole stage, but develop directly as little frogs inside the egg.

The frog, that measures less than 2 cm, was discovered by Andreas Hertz and his colleagues, who are reptile and amphibian specialists at the Senckenberg Research Institute in Frankfurt am Main; Germany. They discovered it in 2010 during several field trips to the Serranía de Tabasará of western Panama a highly understudied part of the Panamanian central mountain range.

"Although we recognized that the male mating call of this species differs from all what we had heard before and therefore suspected it to be new, much effort was involved to finally spot it in the dense vegetation", said Hertz. "When we finally caught the first individuals by hand, we noticed that it dyes one's fingers yellow when it is handled. The scientific name (Diasporus citrinobapheus) of this new frog refers to this characteristic and means yellow dyer rainfrog."

To assure the validity of the frog as a new species, the biologists studied body structure, coloration, molecular genetic data, and vocalizations of a series of individuals, and compared the results with the data derived from closely related species.

Additionally, the researchers took into consideration the possibility that the yellow stain may be poisonous and performed an analysis of skin secretions. "We cannot say whether the dye is any good as a predatory defence, as we could not find any poisonous components. Maybe the colour is just easily washed out and has no particular function. However, for now, this peculiarity of the new species remains enigmatic." said Hertz.

The full article is available on-line.

Citation
Hertz A, Hauenschild F, Lotzkat S, Köhler G (2012) A new golden frog species of the genus Diasporus (Amphibia, Eleutherodactylidae) from the Cordillera Central, western Panama. ZooKeys 196: 23-46. doi: 10.3897/zookeys.196.2774

Sunday, May 20, 2012

Sedentary Sea Snakes


The turtleheaded sea snake, Emydocephalus annulatus
Drawing by Ethel King, Australian Museum.

A mark and re-capture study of the turtleheaded sea snake, Emydocephalus annulatus, in New Caledonia suggests that snakes living in two bays less than 1.15 kilometers apart are separate populations. Lukoschek and Shine (2012) found that while the snakes could swim from one bay to the other, they rarely do so. More that eight hundred snakes were recaptured and only two individuals had moved between the bays. 136 snakes were genotyped for eleven microsatelite loci and the two populations were found to have statistically significant genetic divergence. The sedentary behavior of these sea snakes has ecological and evolutionary implications but is also important for their conservation and management. The authors suggest that sea snakes may be poor colonists and this may account for their highly heterogeneous distributions across several spatial scales, but perhaps most importantly coral reef habitats. Populations of snakes associated with reefs operate as separate ecological units and, as such, local disturbances will have mostly local impacts. However, once a local population has been damaged establishing a new population is likely to be slow. Thus sea snakes may be vulnerable to habitat disturbances brought about by huamn activities or environmental factors, and explain the recent precipitous population declines and local extinctions of turtleheaded sea snakes, as well as other reef-associated species. These local extinctions include a previously large population of turtleheaded sea snakes at Ashmore Reef in the Timor Sea. The results of this study also raise concern about the potential for this population to recover, as well as for the recovery of critically endangered and endangered small-range endemics in the genus Aipysurus, which have undergone similar local extinctions at Ashmore Reef. The entire article is available on-line.

Citation
Lukoschek, V. and Shine, R. (2012), Sea snakes rarely venture far from home. Ecology and Evolution. doi: 10.1002/ece3.256

Friday, May 18, 2012

A Giant Pelomedusiod Turtle from Colombia

Above: Reconstruction of Carbonemys preying upon a small crocodylomorph.

Picture a turtle the size of a Smart car, with a shell large enough to double as a kiddie pool. Paleontologists from North Carolina State University have found just such a specimen – the fossilized remains of a 60-million-year-old South American giant that lived in what is now Colombia.

The turtle in question is Carbonemys cofrinii, which means “coal turtle,” and is part of a group of side-necked turtles known as pelomedusoides. The fossil was named Carbonemys because it was discovered in 2005 in a coal mine that was part of northern Colombia’s Cerrejon formation. The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby - and is believed to belong to the same species - measures 172 centimeters, or about 5 feet 7 inches, long. That’s the same height as Edwin Cadena, the NC State doctoral student who discovered the fossil.

“We had recovered smaller turtle specimens from the site. But after spending about four days working on uncovering the shell, I realized that this particular turtle was the biggest anyone had found in this area for this time period – and it gave us the first evidence of giantism in freshwater turtles,” Cadena says.

Smaller relatives of Carbonemys existed alongside dinosaurs. But the giant version appeared five million years after the dinosaurs vanished, during a period when giant varieties of many different reptiles – including Titanoboa cerrejonensis, the largest snake ever discovered – lived in this part of South America. Researchers believe that a combination of changes in the ecosystem, including fewer predators, a larger habitat area, plentiful food supply and climate changes, worked together to allow these giant species to survive. Carbonemys’ habitat would have resembled a much warmer modern-day Orinoco or Amazon River delta.

In addition to the turtle’s huge size, the fossil also shows that this particular turtle had massive, powerful jaws that would have enabled the omnivore to eat anything nearby – from mollusks to smaller turtles or even crocodiles.

Thus far, only one specimen of this size has been recovered. Dr. Dan Ksepka, NC State paleontologist and research associate at the North Carolina Museum of Natural Sciences, believes that this is because a turtle of this size would need a large territory in order to obtain enough food to survive. “It’s like having one big snapping turtle living in the middle of a lake,” says Ksepka, co-author of the paper describing the find. “That turtle survives because it has eaten all of the major competitors for resources. We found many bite-marked shells at this site that show crocodilians preyed on side-necked turtles. None would have bothered an adult Carbonemys, though – in fact smaller crocs would have been easy prey for this behemoth.”

The paleontologists’ findings appear in the Journal of Systematic Palaeontology. Dr. Carlos Jaramillo from the Smithsonian Tropical Research Institute in Panama and Dr. Jonathan Bloch from the Florida Museum of Natural History contributed to the work. The research was funded by grants from the Smithsonian Institute and the National Science Foundation.

Citation
Edwin Cadena, Dan Ksepka, Carlos Jaramillo, Jonathan Bloch. New pelomedusoid turtles from the late Palaeocene Cerrejon Formation of Colombia and their implications for phylogeny and body size evolution. Journal of Systematic Palaeontology, 2012 (in press)

Wednesday, May 16, 2012

The Cold Tolerant Red-bellied Snake


The red-bellied snake, Storeria occipitomaculata, is a small, fossorial thamnophiine snake with a disjunjct distribution that includes the area from eastern North Dakota to Nova Scotia, south to Florida, and west to eastern Texas. Speculation that the Great Plains  acts as a barrier to westward dispersal has been hypothesized, due to the fact that they are absent from large areas of remnant prairie in the midwest and east, an idea that goes back to the work done by Harold Trapido in the 1940's. This hypothesis appears to be wrong, Bown and Phillips examined 387 preserved specimens, literature records, and unpublished data and found the species is distributed throughout much of the state of Illinois. Their study suggests red-bellied snakes do indeed inhabit woodlands but that they are not adapted for primary forest, and the authors found they do in fact use prairie and prairie-like habitats. Brown and Philips suggest red-bellied snakes are adapted for cool to cold envuironments ands that they inhabited the ice rim of the Wisconsin glacial episode, following the ice northward as it retreated. Evidence for this comes from the snakes distribution in northern prairies and coniferous forests.

Citation
Brown, L.E. and C.A. Phillips. 2012. Distribution, habitat, and zoogeography of the semifossorial red-belied snake Storeria occipitomaculata (Storer) in Illinois. Illinois Natural History Survey Bulletin 39 (5):297-322.

New Pharmaceutical Product from Heloderma

A drug made from the saliva of the Gila monster lizard is effective in reducing the craving for food. Researchers at the Sahlgrenska Academy, University of Gothenburg, have tested the drug on rats, who after treatment ceased their cravings for ordinary food and also chocolate.

An increasing number of patients suffering from type 2 diabetes are offered a pharmaceutical preparation called Exenatide, which helps them to control their blood sugar. The drug is a synthetic version of a natural substance called exendin-4, which is obtained from a rather unusual source -- the saliva of the Gila monster lizard (Heloderma suspectum), North America's largest lizard.

Researchers at the Sahlgrenska Academy at the University of Gothenburg, have now found an entirely new and unexpected effect of the lizard substance.

In a study with rats published in the Journal of Neuroscience, Assistant Professor Karolina Skibicka and her colleagues show that exendin-4 effectively reduces the cravings for food.

"This is both unknown and quite unexpected effect," comments an enthusiastic Karolina Skibicka: "Our decision to eat is linked to the same mechanisms in the brain which control addictive behaviours. We have shown that exendin-4 affects the reward and motivation regions of the brain."

The implications of the findings are significant" states Suzanne Dickson, Professor of Physiology at the Sahlgrenska Academy: "Most dieting fails because we are obsessed with the desire to eat, especially tempting foods like sweets. As exendin-4 suppresses the cravings for food, it can help obese people to take control of their weight," suggests Professor Dickson.

Research on exendin-4 also gives hope for new ways to treat diseases related to eating disorders, for example, compulsive overeating.

Another hypothesis for the Gothenburg researchers' continuing studies is that exendin-4 may be used to reduce the craving for alcohol.

"It is the same brain regions which are involved in food cravings and alcohol cravings, so it would be very interesting to test whether exendin-4 also reduces the cravings for alcohol," suggests Assistant Professor Skibicka.

Suzanne L. Dickson, Rozita H. Shirazi, Caroline Hansson, Filip Bergquist, Hans Nissbrandt, and Karolina P. Skibicka. The Glucagon-Like Peptide 1 (GLP-1) Analogue, Exendin-4 Decreases the Rewarding Value of Food: A New Role for the Mesolimbic GLP-1 Receptors. Journal of Neuroscience, April 4, 2012 DOI: 10.1523/%u200BJNEUROSCI.6326-11.2012

Monday, May 14, 2012

Giant Tiger Snakes on Islands


Some populations of tiger snakes stranded for thousands of years on tiny islands surrounding Australia have evolved to be giants, growing to nearly twice the size of their mainland cousins. Now, new research in The American Naturalist suggests that the enormity of these elapids was driven by the need to have big-mouthed babies.
Mainland tiger snakes, which generally max out at 35 inches (89 cm) long, patrol swampy areas in search of frogs, their dietary staple. When sea levels rose around 10,000 years ago, some tiger snakes found themselves marooned on islands that would become dry and frog-free. With their favorite food gone, the island snakes “are now thriving on an altered diet consisting of skinks, rodents, and nesting oceanic bird chicks,” said study author Fabien Aubret of La Station d'Ecologie Experimentale du CNRS à Moulis.

Along with the dietary shift came dramatic changes in the snakes’ adult body sizes. On some islands, the snakes shrank, becoming significantly smaller than mainland snakes. But other islands have produced giants, measuring 60 inches (1.5 meters) and weighing as much as three times more than mainland snakes.

Aubret hypothesized that the size of available prey on each island was driving the variation in body size. Snakes are gape-limited predators, meaning they swallow their prey whole and can only dine on animals they can wrap their mouths around. This gape limitation would be most pronounced in newborn snakes, when their mouths are at their smallest. Simply put, baby snakes born too small to partake of the local cuisine would have little chance to survive. Where prey animals are larger, selection would favor larger newborn snakes—with larger mouths. That head start in size at birth could be the reason for larger size in adulthood.

To test his idea, Aubret took field expeditions to 12 islands, collecting and measuring 597 adult snakes. He released the males and non-pregnant females, and brought 72 pregnant snakes back to the lab. After the snakes gave birth, he measured each of the 1,084 babies they produced. He then looked for correlations between snake size at birth and the size of prey animals available on each island. He also tested for correlations between birth size and adult size.

“The results were unequivocal: snake body size at birth tightly matches the size of prey available on each island,” Aubret said.

As predicted, where prey animals were bigger, newborn snakes were bigger and they grew up to be bigger adults. Where prey animals were smaller, newborn snakes followed suit, leading to smaller adults.

Ecologists have long been interested in the peculiarities of island animals. Observations of pygmy elephants and giant rats led a biologist named J. Bristol Foster to propose what became known as the Island Rule. In general, Foster surmised, big animals on islands tend to get smaller than mainland counterparts because of limited access to food. Small animals tend to get larger because islands tend to have fewer predators. Since it was proposed in the 1960s, numerous exceptions to Foster’s rule have been noted, and scientists now agree that the ecological factors that influence island body size are far more complex than Foster had imagined.

 “Mean adult body size has always been used as a traditional measure in the literature,” he writes. “On the other hand, patterns of variation for body size at birth in island populations have received, to my knowledge, no attention at all.”

“This study confirms that adult size variations on islands may be a nonadaptive consequence of selection acting on birth size,” he said. “Animals may become either giant or dwarf adults on islands for the simple fact that they were born either unusually large or small bodied.”

Citation
Fabien Aubret, “Body-Size Evolution on Islands: Are Adult Size Variations in Tiger Snakes a Nonadaptive Consequence of Selection on Birth Size?” The American Naturalist 179:6 (June 2012). Photos by Fabien Aubret.

New Cordylus from Central Africa


Cordylus marunguensis

An international collaboration of scientists has announced the discovery of a new species of lizard from remote, war-torn mountains in Central Africa. The new species, Cordylus marunguensis, is described from the Marungu Plateau, a montane area west of Lake Tanganyika in south-eastern Democratic Republic of the Congo.

The expedition that led to the new species discovery in 2010 was led by Eli Greenbaum, assistant professor of evolutionary genetics at the University of Texas at El Paso, and Chifundera Kusamba, a research scientist from the Centre de Recherche en Sciences Naturelles in Congo. The team spent several weeks exploring the area around the plateau for new species of amphibians and reptiles. The new lizard was discovered near the village of Pepa under rocks in grassy fields that were riddled with landmines and unexploded ordnance left over from a heavy conflict that engulfed the region at the turn of the 21st century.

Suspecting the lizard represented a new species, Greenbaum sent DNA samples to Edward Stanley, a student at the American Museum of Natural History’s Richard Gilder Graduate School in New York City. Mr. Stanley compared the DNA of the Marungu lizard to similar species throughout Africa and confirmed that it was indeed a new species to science. He bolstered the finding by using a new technique called high resolution x-ray computer tomography to reconstruct the lizard’s skeleton in three dimensions, the first time such a technique has been used in a living lizard species description.

The digital reconstruction confirmed the presence of tiny bones called osteoderms in the heavily armored scales of the new species. The reinforced scales are thought to protect the lizards from attacks by predators, and in some cases, to allow the animals to avoid attacks by wedging themselves between small, rocky crevices.

The discovery of the new species offers hope for conservation, even though none of the lizard’s habitat is currently protected.

"Although the Marungu Plateau has been heavily damaged by warfare and habitat destruction, the new lizard proves that it is not too late to implement conservation efforts," said Greenbaum. It is hoped that the new discovery will lead to the protection of the plateau’s unique plant and animal biodiversity in the near future.

Thursday, May 10, 2012

Eastern Diamondback Rattlesnake Closer to Endangered Species Act Protection


World's Largest Rattlesnake Threatened by Habitat Destruction, Persecution

TALLAHASSEE— The U.S. Fish and Wildlife Service announced today that the eastern diamondback rattlesnake may qualify for Endangered Species Act protection. Today’s finding responds to a 2011 petition filed by the Center for Biological Diversity, noted snake expert Dr. Bruce Means, Protect All Living Species and One More Generation. Eastern diamondbacks are the largest rattlesnakes in the world and are in steep decline because of habitat destruction and human persecution.

“Eastern diamondbacks are rapidly disappearing all across the southeastern United States, and in some states they’ve more or less vanished. They need Endangered Species Act protection to survive,” said the Center’s reptile-and-amphibian specialist, Collette Adkins Giese. “The Endangered Species Act has a nearly perfect record of saving species on the brink of extinction — it’s our best tool for saving diamondbacks.”

The eastern diamondback was once abundant in longleaf pine forests across the Southeast, but only 2 percent to 3 percent of the species’ original habitat still exists. Also, with no limits on rattlesnake harvest in many southern states, the animals continue to be targeted for their skins and for sport. Because the snakes are habitat specialists that depend on pine and other open-canopy forests, habitat destruction and fragmentation are the principal cause of their decline.

Today’s decision triggers a full review of the snake’s status by the Fish and Wildlife Service, which must make a final decision on Endangered Species Act protection within a year. The eastern diamondback will likely be added to the list of candidate species that need protection, but not until the Service works its way through a backlog of species already under consideration for listing. As part of a historic legal settlement with the Center, the Service will make decisions on whether hundreds of imperiled species should be added to the endangered species list by 2017.

“The loss of longleaf pine habitats threatens the rich biodiversity of the coastal plains,” said Bruce Means, president of the Coastal Plains Institute and Land Conservancy. “Protecting remaining patches of longleaf pine from unsustainable human development will help the diamondback and other species that depend on these forests, such as the red-cockaded woodpecker, indigo snake and gopher tortoise.”

Exploitation by humans is also having a severe impact on remaining eastern diamondback populations. Thousands of the creatures are killed each year for their skins and meat, with no harvest limits, in South Carolina, Georgia, Florida, Mississippi, Alabama and Louisiana. And in Alabama and Georgia, eastern diamondbacks are targeted by “rattlesnake roundups” — festivals that offer prizes to encourage hunters to collect, then kill, the imperiled snakes.

“So many people are scared of rattlesnakes and want to kill them. But all species are on this planet for a reason,” said 10-year-old student Carter Ries, founder of One More Generation. “We just want to make sure that these rattlers are going to be around for future generations.”

Eastern diamondback rattlesnakes pose little public safety risk; although they’re venomous, more people are killed every year by lightning strikes and bee stings. And the number of people who are bitten by snakes during outdoor activities is very low. Those most likely to be bitten are snake handlers who either keep venomous snakes in captivity or work with them professionally. Nevertheless, malicious killings by those who perceive the snake as a threat are contributing to its decline.

“Survival of these snakes in large part depends on whether people continue to persecute them or instead choose to allow these amazing creatures to share the land with us,” said Bill Matturro of Protect All Living Species. “In the Southeast, we are blessed with a rich natural heritage of animals and plants. All of these species — even the rattlesnakes — should be allowed to exist.”


Monday, May 7, 2012

Pituophis ruthveni Releases

Louisiana Pine Snake, Pituophis ruthveni
Asheville, NC -- On May 1, USDA Forest Service, U.S Fish and Wildlife Service, Louisiana Department of Wildlife and Fisheries, the Memphis Zoo, and other partners released seven young Louisiana pine snakes on a restored longleaf pine stand in the Kisatchie National Forest in Louisiana. The release is the fourth in 2 years, part of a plan to restore a very rare snake to its range in Louisiana. Last year the partners released 20 newly hatched snakes; this year’s snakes are 6 months old and about 3 feet long.

Four to 5 feet long as an adult and covered with a striking pattern of black, brown and beige, the Louisiana pine snake is a rare sight in its native range in east-central Texas and across Louisiana. Craig Rudolph, Forest Service Southern Research Station research ecologist and a member of the reintroduction team, has monitored the species for decades, and concurs with other herpetologists that it well may be one of the rarest snake species in the United States. Snakes released for the restoration effort are hatched and raised in zoos, and are the offspring of Louisiana pine snakes captured from the wild.

Already listed as threatened in Texas and a candidate for listing under the Federal Endangered Species Act, the Louisiana pine snake population has declined because of alterations to the its native pine longleaf pine habitat and that of its prey.

A nonvenomous species, the Louisiana pine snake spends most of its time underground in burrows of its favorite prey, the Baird’s pocket gopher. The ideal habitat for both species consists of dry, sandy-soiled ridges covered with longleaf pine trees and an open understory of the grasses and forbs the pocket gophers feed on. This habitat largely disappeared due to commercial logging in the late 19th and early 20th centuries and subsequent fire suppression.

“Without fire, these upland pine savannahs rapidly develop a midstory that shades out the grassy understory that pocket gophers need,” says Rudolph. “The release site on the Kisatchie, which was intentionally restored for red-cockaded woodpecker habitat, should also support pocket gophers and Louisiana pine snakes.”

Only time will tell whether the Louisiana pine snake can be sustainably restored to longleaf pine ecosystems in its native range.

Researchers implanted each of the snakes released on May 1 with a passive integrated transponder (PIT) that allows them to be tracked by recorders installed on the site. “So far we’ve not had much success with the recorders, which are dug into the ground in four places on the release site,” says Rudolph. “We’ve recorded activity in the first weeks, but nothing later on. This is not unexpected, since these snakes have a large home range and probably leave the immediate area. We need to get good population estimates for the areas we’ve released in, but the only way to get data is by trapping, which is very time-consuming and expensive.”

The animal’s biology presents another constraint to its survival. While most other snakes produce large clutches of eggs, the Louisiana pine snake lays only three to five eggs, and in captive breeding programs, sometimes only one or two eggs per clutch hatch. This low reproductive rate means that the species might not recover quickly in the wild. Rudolph worries that breeding programs, which rely on the progeny of only 16 founder individuals caught in the wild, may be producing snakes that are not genetically diverse enough to survive when released.

“In the best-case scenario, there would still be Louisiana pine snakes out there that we’ve never caught that can breed with the released snakes,” says Rudolph. “We have traps operating for thousands of trap days a year in Texas, for instance, and haven’t caught a single snake in three years. When we find better ways to monitor our releases, perhaps we’ll find some additional populations.”

Saturday, May 5, 2012

A Huge Plio-Pleistocene Croc From Africa

The illustration shows the comparative sizes of ancient/modern crocodiles and ancient/
modern humans. Illustration by Chris Brochu.
A crocodile large enough to swallow humans once lived in East Africa, according to a University of Iowa researcher.

"It’s the largest known true crocodile,” says Christopher Brochu, associate professor of geoscience. “It may have exceeded 27 feet in length. By comparison, the largest recorded Nile crocodile was less than 21 feet, and most are much smaller.”

Brochu’s paper on the discovery of a new crocodile species was just published in the May 3 issue of the Journal of Vertebrate Paleontology. The new species lived between 2 and 4 million years ago in Kenya. It resembled its living cousin, the Nile crocodile, but was more massive.

He recognized the new species from fossils that he examined three years ago at the National Museum of Kenya in Nairobi. Some were found at sites known for important human fossil discoveries. “It lived alongside our ancestors, and it probably ate them,” Brochu says. He explains that although the fossils contain no evidence of human/reptile encounters, crocodiles generally eat whatever they can swallow, and humans of that time period would have stood no more than four feet tall.

"We don’t actually have fossil human remains with croc bites, but the crocs were bigger than today’s crocodiles, and we were smaller, so there probably wasn’t much biting involved,” Brochu says.

He adds that there likely would have been ample opportunity for humans to encounter crocs. That’s because early man, along with other animals, would have had to seek water at rivers and lakes where crocodiles lie in wait.

Regarding the name he gave to the new species, Brochu said there was never a doubt.

The crocodile Crocodylus thorbjarnarsoni is named after John Thorbjarnarson, famed crocodile expert and Brochu’s colleague who died of malaria while in the field several years ago.

“He was a giant in the field, so it only made sense to name a giant after him,” Brochu says. “I certainly miss him, and I needed to honor him in some way. I couldn’t not do it.”

Among the skills needed for one to discover a new species of crocodile is, apparently, a keen eye.

Not that the fossilized crocodile head is small—it took four men to lift it. But other experts had seen the fossil without realizing it was a new species. Brochu points out that the Nairobi collection is “beautiful” and contains many fossils that have been incompletely studied. “So many discoveries could yet be made,” he says.

In fact, this isn’t the first time Brochu has made a discovery involving fossils from eastern Africa. In 2010, he published a paper on his finding a man-eating horned crocodile from Tanzania named Crocodylus anthropophagus—a crocodile related to his most recent discovery.

Brochu says Crocodylus thorbjarnarsoni is not directly related to the present-day Nile crocodile. This suggests that the Nile crocodile is a fairly young species and not an ancient “living fossil,” as many people believe. “We really don’t know where the Nile crocodile came from,” Brochu says, “but it only appears after some of these prehistoric giants died out.”

Christopher A. Brochu, Glenn W. Storrs. A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity ofCrocodylusin Africa. Journal of Vertebrate Paleontology, 2012; 32 (3):587

Wednesday, May 2, 2012

Many New Skinks

An Anguilla Bank skink. Blair Hedges and his team have discovered
 and scientifically named 24 new species of lizards known as skinks.
Credit: Karl Questel
In a single new scientific publication, 24 new species of lizards known as skinks, all from islands in the Caribbean, have been discovered and scientifically named. According to Blair Hedges, professor of biology at Penn State University and the leader of the research team, half of the newly added skink species already may be extinct or close to extinction, and all of the others on the Caribbean islands are threatened with extinction. The researchers found that the loss of many skink species can be attributed primarily to predation by the mongoose -- an invasive predatory mammal that was introduced by farmers to control rats in sugarcane fields during the late 19th century. The research team reports on the newly discovered skinks in a 245-page article published today (April 30) in the journal Zootaxa.

About 130 species of reptiles from all over the world are added to the global species count each year in dozens of scientific articles. However, not since the 1800s have more than 20 reptile species been added at one time. Primarily through examination of museum specimens, the team identified a total of 39 species of skinks from the Caribbean islands, including six species currently recognized, and another nine named long ago but considered invalid until now. Hedges and his team also used DNA sequences, but most of the taxonomic information, such as counts and shapes of scales, came from examination of the animals themselves.

"Now, one of the smallest groups of lizards in this region of the world has become one of the largest groups," Hedges said. "We were completely surprised to find what amounts to a new fauna, with co-occurring species and different ecological types."

He said some of the new species are six times larger in body size than other species in the new fauna.

Hedges also explained that these New World skinks, which arrived in the Americas about 18 million years ago from Africa by floating on mats of vegetation, are unique among lizards in that they produce a human-like placenta, which is an organ that directly connects the growing offspring to the maternal tissues that provide nutrients.

"While there are other lizards that give live birth, only a fraction of the lizards known as skinks make a placenta and gestate offspring for up to one year," Hedges said.

He also speculated that the lengthy gestational period may have given predators a competitive edge over skinks, since pregnant females are slower and more vulnerable.

"The mongoose is the predator we believe is responsible for many of the species' close-to-extinction status in the Caribbean," Hedges said. "Our data show that the mongoose, which was introduced from India in 1872 and spread around the islands over the next three decades, has nearly exterminated this entire reptile fauna, which had gone largely unnoticed by scientists and conservationists until now."

According to Hedges, the "smoking gun" is a graph included in the scientific paper showing a sharp decline in skink populations that occurred soon after the introduction of the mongoose. Hedges explained that the mongoose originally was brought to the New World to control rats, which had become pests in the sugarcane fields in Cuba, Hispaniola, Puerto Rico, Jamaica and the Lesser Antilles. While this strategy did help to control infestations of some pests; for example, the Norway rat, it also had the unintended consequence of reducing almost all skink populations.

"By 1900, less than 50 percent of those mongoose islands still had their skinks, and the loss has continued to this day," Hedges said.

This newly discovered skink fauna will increase dramatically the number of reptiles categorized as "critically endangered" by the International Union for Conservation of Nature in their "Red List of Threatened Species," which is recognized as the most comprehensive database evaluating the endangerment status of various plant and animal species.

"According to our research, all of the skink species found only on Caribbean islands are threatened," Hedges said. "That is, they should be classified in the Red List as either vulnerable, endangered, or critically endangered. Finding that all species in a fauna are threatened is unusual, because only 24 percent of the 3,336 reptile species listed in the Red List have been classified as threatened with extinction. Most of the 9,596 named reptile species have yet to be classified in the Red List."

Hedges explained that there are two reasons why such a large number of species went unnoticed for so many years, in a region frequented by scientists and tourists.

"First, Caribbean skinks already had nearly disappeared by the start of the 20th century, so people since that time rarely have encountered them and therefore have been less likely to study them," he said. "Second, the key characteristics that distinguish this great diversity of species have been overlooked until now."

Hedges also noted that many potential new species of animals around the world have been identified in recent years with DNA data. However, much more difficult is the task of following up DNA research with the work required to name new species and to formally recognize them as valid, as this team did with Caribbean skinks.

The other member of the research team, Caitlin Conn, now a researcher at the University of Georgia and formerly a biology major in Penn State's Eberly College of Science and a student in Penn State's Schreyer Honors College at the time of the research, added that researchers might be able to use the new data to plan conservation efforts, to study the geographic overlap of similar species, and to study in more detail the skinks' adaptation to different ecological habitats or niches. The research team also stressed that, while the mongoose introduction by humans now has been linked to these reptile declines and extinctions, other types of human activity, especially the removal of forests, are to blame for the loss of other species in the Caribbean.

Citation
Hedges, S.B & C.E, Conn. 2012. A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae). Zootaxa 3288:1-244.