Friday, October 7, 2011

Schuett/Repp Suizo Mountain - Crotalus scutulatus

Howdy Herpers, 5 October 2011

I got off to a bad start on the evening of 27 August. I hopped out of my truck, and prepared to open a data sheet by placing a thermometer in a nearby palo-verde tree. The fact that moments later, I forgot which palo-verde tree I thrust said thermometer into was the beginning of the bad start. Anybody who works after nightfall with various instruments of science scattered about knows the danger of not paying rapt attention to placement. The darkness that is often associated with nightfall can make even the simplest chore a nightmare in flandickery if full focus is not applied at all times.

As an amused Blake Thomason looked on, I walked in circles around the various pieces of surrounding shrubbery, muttering curses and bitch slapping myself incessantly. After about ten minutes of this, Blake took pity on me, and began to scour the area around our parking lot as well. About two minutes later, he called me over and said: "Hey Amigo--look what I found!"

Image 1: "Hey Amigos--look what Blake found!" It's a Mojave Rattlesnake (Crotalus scutulatus), only the second one ever found in the 10.5 year duration of the Schuett/Repp Suizo Mountain study. This is an in situ image of the snake as Blake found it--less than 20 feet from our parking spot!

The previous Mojave Rattlesnake was found 22 July 2009. At that point in time, we didn't have the means or desire to radiotrack a "scut." We were fearful that since they don't normally occur on our plot, we might have a wayward snakethat would wander well off plot and be lost.

Image 2: However, with the scut found on 27 August, we decided we'd try our hand at tracking him--regardless of any would-be wandering. This is obviously a posed image, taken the day following the capture.


In no time flat, we had a transmitter in him, and began tracking.

Image 3: In the early going, tracking good old Blake the snake went slicker than greased owl scat. On 7 September, he was found behaving very atrox-ish, coiled in prickly pear next to a pack rat midden. His total move was ~100 meters to the southeast of his capture spot. He had wrapped around to the south side of our hill. I expected him to move southward, out to the creosote flats by Park Link Drive.


Image 4: Knowing that this snake might just boogie right off the plot, staying with him became imperative. The next tracking session was on 11 September. He had shifted westward about 100 meters, and had actually crossed Main Street.

Image 5: I tracked him again on 13 September. He had shifted about 200 meters to the northwest. Thus far, there was nothing to indicate that there was trouble ahead. 

On 17 September, I could not get his signal from our normal parking spot. Blake the person and I took a drive to the top of Iron Mine Hill, and picked up a very faint series of blips. They were coming in from the north, and the weak blips indicated he was a LONG way out there. We drove back down the hill, (encountering my shadow, tortoise number 505 on the way down), and headed across Suizo Wash. We got the signal from the other side. At that point, as we had three other people waiting for us at the parking spot, we drove back and formed a two truck caravan to work the back roads that occur haphazardly around the countryside. We drove around for over an hour, the results being akin to the sound of one hand clapping. My companions were still gung ho to keep trying, but I pulled the plug on the effort. We were out there to find new snakes, (which we did-but that is another story), and I wasn't about to waste five pairs of eyeballs by driving around all night in no mans land looking for a lost child. (The thought of putting his image on a milk carton occurred to me. "Have you seen this child?")

On 24 September, the same scenario repeated itself. I drove to the top of the hill, once again freaking out poor old tortoise number 505, who was peacefully munching on some grass at the edge of the road. The signals came in ever-so-faintly, and I drove to the edge of the earth with zero luck again.

Great feats of deep thinking began. How did I do this back in the day when we had big male Black-tailed Rattlesnakes that would take off? Then it hit me. The next time I got the signal, I would make cock sure of which direction it was coming from, and hike him out. None of this driving wildly around on back roads hoping for a convenient parking place. Hiking them out is what I used to do with lost children in the past, before I got fat and lazy.

Thus it came to pass that on 28 September, I drove to the top of Iron Mine Hill. Once again, poor old 505 was choking down some dry grass at the edge of the road. This time, he paused long enough to give me a dirty look, and then continued to browse. Once again, a faint signal came in, this time from the northwest. I aligned my compass in the direction, and noted that I could get about 100 meters closer to him by driving to a place that was in direct line with the compass/signal.

I started the hike at 1715. I told myself that I would walk until 1810 before I threw up the white flag. At precisely 1800, the first faint blips appeared again. The crowd went wild!

Image 6: By 1815, I had tracked him down. He had moved an astounding 1,885 meters from his point of capture. As good fortune would have it, he followed the one road that leads in that direction. I could have driven and parked right beside him that night.

 
On 1 October, another drive to the top of our hill yielded no tortoise 505, and no signal. Off we went on a wild drive to try to find the signal, with no luck.

On 2 October, John Slone joined me for another attempt. At the last possible second, we caught a faint glimmer of a signal. It wound up being nearly an hour later, but we finally we tracked him down.
Image 7: He was now 4,280 meters northwest of his capture spot. That is over 2.6 miles!


Image 8: And of course, when we found him, he was traveling in that same northwest direction he has been heading since we first found him. Just after this image was taken, he exploded into a defensive posture, rattling and loudly hissing. He was not glad too see us! 

 

The paved road gradient that leads to our plot takes one through some changes in the landscape that in turn leads to changes in the herpetofauna that inhabit the region. To the west end of the road, Sidewinders, Mojave Rattlesnakes, and Desert Iguanas can be found. These all peter out together about one wile west of our plot. We knew when we installed the transmitter that we might be in for a difficult subject to track.

Blake the Snake is probably one of those rare individuals that cut loose from a smaller home range to check out the world around him. He found us at the eastern edge of his journey, and that was likely not a good experience for him. I speculate that he is now heading back to his home range. As one who has herped the whole length of the area, I have only once encountered a Mojave Rattlesnake once in November.
That means Blake the Snake is going to hibernate soon. If I can stay on top of him until that point, we probably will have him at the point where he is back home again.

Image 9, By Royce Ballinger. View from Iron Mine Hill looking northwest. To the left background, local herpers will recognize Picacho Peak. To the right, the Picaho Mountains. Smack dab in the middle of the two mountain ranges is the lone hill that is called "Huerfono" (The Orphan in Spanish). Blake the Snake is slightly past Huefono, and about 1/2 mile to the north. 


This here is Roger Repp, signing off from Southern Arizona, where the SNAKES are strong.......................

Tuesday, October 4, 2011

The Mekong Mud Snake

The Mekong Mud Snake, Enhydris subtaeniata. JCM
From the mid-19th century to the mid-20th century it was popular to lump species, placing names in synonymies of older names if there was reason to suspect they might be the same species. With snakes, characters like similar scale rows at mid-body, similar color patterns, combined with similar distributions resulted in species named by one person being placed in the synonymy of another species by somebody else. The result, zoologists in the early 20th century greatly underestimated animal diversity. Such was the case of the Mekong Mud Snake, Enhydris subtaeniata. Rene Bourret described Hypsirhina enhydris subtaeniata in an obscure French colonial journal (Bulletin General de l'Instruction Publique) in French Indochina (Vietnam), in 1943 Malcolm Smith placed the name in the synonymy of Enhydris jagorii. However, it was recognized by Murphy (2007) as a valid species of the genus Enhydris, and established as a member of the enhydris clade based on molecular work (Karns et. al. 2010).

As its name suggests, the Mekong Mud Snake is endemic to the middle and lower Mekong drainage, but also occurs at Bung Boraphet in central Thailand. It is a highly aquatic, fishing eating snake they reaches high population densities at some locations.  In a new paper Vimoksalehi Lukoschek and colleagues (2011) report high genetic diversity in Enhydris subtaeniata between seven sampled localities, while genetic diversity was low within each sampled locality. The authors suggest the diversity is the result of genetic isolation of populations by changes in the Quaternary landscapes of Indochina and that the snake was able to colonize central Thailand using corridors of ancient, now drowned river valleys.

Literature
Karns, D. R., Lukoschek, V., Osterhage, J., Murphy, J, C., and Voris, H. K. (2010) Phylogeny and biogeography of the Enhydris clade (Serpentes: Homalopsidae). Zootaxa, 2452. pp. 18-30. ISSN 1175-5334.

Lukoschek, V., Osterhage, J. L., Karns, D. R., Murphy, J. C. and Voris, H. K. (2011), Phylogeography of the Mekong mud snake (Enhydris subtaeniata): the biogeographic importance of dynamic river drainages and fluctuating sea levels for semiaquatic taxa in Indochina. Ecology and Evolution. doi: 10.1002/ece3.29

Murphy, J. C. 2007. Homalopsid Snakes, Evolution in the Mud. Krieger Publishing, Malabar, FL.

Sunday, October 2, 2011

More on The Golf Course & its Endangered Herpetofauna

Rana draytonii, WEI
An article on the San Francisco Examiners web site by Carole Groom and Adrienne J. Tissier (both members of the San Mateo County Board of Supervisors) is reporting that San Mateo County and Pacifica have a framework for a plan to make Sharp Park a place where golfers from all socioeconomic strata successfully co-exist with sensitive coastal species. They suggest the golf course can be reconfigured to support the endangered snakes and threatened frogs, while recapturing some of Dr. Alister MacKenzie (the desinger of the golf course in the 1920's) original layouts. Additionally they report that San Mateo County has already identified private sources willing to underwrite most (maybe all) of this proposed peaceful co-existence.You can find the entire article on-line.

Sharp Park Golf Course contains two threatened species the California Red-legged Frog, Rana draytonii, a species that has lost much of its habitat to development and a species that is often referred to as “Twain’s frog” because it was the central character in Mark Twain’s short story “The Celebrated Jumping Frog of Calaveras County,” it was a favorite competitor in jumping frog competitions—until the California red-legged frog was displaced by species imported from other parts of the world. Rana draytonii became a staple of the diet of the forty-niners during the California Gold Rush, and eventually became an item on the menu of San Francisco’s finest dining establishments. The golf course operation has been killing California red-legged frogs for many years. Every year when normal winter rains occur frogs begin to breed at Laguna Salada and Horse Stable Pond, laying egg-masses that attach to aquatic vegetation. Because of the golf course’s poor design and unfortunate placement, these same winter rains cause several of the golf course’s fairways to flood. For many years, the golf course would simply pump the water through the sea wall and drain the water off the course: and in the process strand frog egg masses that would desiccate and die, losing entire generations of this threatened species.
Thamnophis sirtalis tetrataenia. WEI

Sharp Park has also provided excellent habitat for the San Francisco Garter Snake, Thamnophis sirtalis tetrataenia. The snakes used Laguna Salada, a lagoon for feeding and the surrounding upland refuge areas and basking habitats. In the 1940s, herpetologist Wade Fox surveyed Sharp Park for the first time, and found the species abundant, suggesting the population was present long-before the recently constructed golf course altered the species’ habitats.

However, Fox also discovered that the golf course was having detrimental impacts on this endemic snake. He found a snake killed by golfers in 1946, and noted that the species probably was frequently killed in this manner. Over the next few decades the snake’s population crashed, and in 2006 the U.S. Fish and Wildlife Service concluded a dead snake found on the property was killed by the course’s lawn mowers. The population crash and the on-going take of the species is particularly worrisome because the survival of the Sharp Park population is key to the success of the species’ overall recovery plan. When the plan was written, Sharp Park had one of only six known potentially viable populations of the species. The plan states that at least four more would need to be established if the species is to have any chance of recovering. Unfortunately, the population at Sharp Park Golf Course has crashed since that time: there may be fewer than 10-20 individuals left on the property.

The San Francisco garter snake was protected by federal law by 1967, and was listed as an endangered species under the Federal Endangered Species Act when the Act was passed in 1973. It is also protected as a Fully Protected Species under California law, and therefore killing the species is not only illegal, but it is also impossible to get a permit to kill the San Francisco garter snake except for restoration projects and scientific research.

Since the garter snake was protected great effort has gone into conserving the species, including the creation of a recovery plan and controlling developments to ensure that the species’ habitats aren’t adversely modified. However, many obstacles still remain to the snake’s survival. Indeed, it is even starting to lose its favored prey, the California red-legged frog is itself threatened with extinction due to development and other threats. Restoring Sharp Park will help both imperiled species thrive. For more information on these two species and the park visit the Wild Equity web site.

Saturday, October 1, 2011

A Matter of Priorities

The Brown Treesnake, Boiga 
irregularis.US Fish & Wildlife

The word ecology is of uncertain origins, it may be derived from the Greek eco, meaning home, or the Latin oeconomia meaning household management.  In either case ecology refers to the economy of nature. Nature's economy is the flow of energy and matter through ecosystems and it is not unlike the flow of cash through society.

Given the current political climate, the country seems divided by those who want to make the wealthy, wealthier (by making the poor, poorer - although they don't admit to this) and those who want to maintain a strong middle class with a more even distribution of wealth.  Returning to the ecosystem analogy, imagine an ecosystem with an excessive number of carnivores (the wealthy - or brown treesnakes) who consume most of the omnivores and herbivores (middle class and poor - or the local bird and lizard fauna). In such an ecosystem the carnivores would soon run out of food and would then start to consume each other.

Those who are complaining about Washington spending too much money, the rhetoric is really code for - you are not spending enough money on my projects or my friends. They really don't want to stop government spending, just control who gets the money. I am all for my tax dollars going for projects that work to restore ecosystems, expand scientific research, and increase jobs for the middle class, but some folks don't agree. Hence, the following article.

HONOLULU (AP) — The Defense and Interior departments are chipping in $2.9 million to rescue a program preventing an invasive snake species from hitchhiking rides from Guam to Hawaii and other warm climates on cargo ships and planes.

Congressional earmarks for years paid to control brown tree snakes, a reptile native to Australia and the Solomon Islands that has eaten to extinction nine out of 11 forest birds on Guam since it was accidentally introduced there after World War II.

Scientists fear the snakes would wipe out Hawaii's many endangered birds if they became established in the 50th state.

Even so, the program was on course to be canceled on Friday — the last day of the current fiscal year — after Congress abandoned earmarks this year. The prospect had alarmed those in Hawaii who try to prevent invasive species from harming the state's fragile environment, and who are already having a harder time doing their jobs because of state budget cuts.

But The Associated Press learned the program got a last-minute reprieve when the Interior and Defense departments last week signed agreements to fund it for the next nine months. The Pentagon is contributing $2.4 million, and Interior is pitching in $500,000.

"We don't want a break in service, obviously, and so that's why there was very much concern over the budget situation," said Mike Pitzler, who oversees the program as the Hawaii, Guam and Pacific Island state director for the U.S. Department of Agriculture's wildlife services section.

The departments are only committing to nine months of funding because they are concerned by the cost at a time when all parts of federal government are grappling with budget cuts. They're expected to discuss in coming months how to continue the program for the last quarter of the fiscal year and beyond.

Pitzler said Thursday he would look for ways to restructure and cut costs, but he's not sure how he can do this without affecting the scope of the work.

"My job will be to make sure that our work isn't compromised, our ability to prevent snakes from leaving Guam is not compromised," he said.

Sen. John McCain, R-Arizona, and others have questioned over the years why the Pentagon should pay to control snakes on Guam.

The program has been the target of fierce critics of earmarks. In 2009, the Citizens Against Government Waste included brown tree snake control in its "Congressional Pig Book" highlighting alleged examples of government pork barrel spending.

Pitzler said the vast majority of cargo leaving Guam belongs to the Navy and the Air Force, so it's natural that the Pentagon pay to screen for the snakes. The program not only protects warm climates like Hawaii and Texas where the snakes would thrive, but also military bases in those states.

The funding pays for 58 workers who maintain 4,000 snake traps around Guam, look for snakes that climb fences at night, poison the reptiles, and search cargo leaving the island.

They use dogs while hunting for snakes hiding on ships and planes leaving Guam, placing a priority on cargo heading for warm locations.

The World’s Most Threatened Sea Turtle Populations


29 September 2011, IUCN Press Release

Top sea turtle experts from around the globe have discovered that almost half (45%) of the world’s threatened sea turtle populations are found in the northern Indian Ocean. The study also determined that the most significant threats across all of the threatened populations of sea turtles are fisheries bycatch, accidental catches of sea turtles by fishermen targeting other species, and the direct harvest of turtles or their eggs for food or turtle shell material for commercial use.

The recent report, produced by IUCN (International Union for Conservation of Nature) Marine Turtle Specialist Group (MTSG) and supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF), is the first comprehensive status assessment of all sea turtle populations globally. The study, designed to provide a blueprint for conservation and research, evaluated the state of individual populations of sea turtles and determined the 11 most threatened populations, as well as the 12 healthiest populations.

“This assessment system provides a baseline status for all sea turtles from which we can gauge our progress on recovering these threatened populations in the future,” explained Roderic Mast, Co-Chair of the MTSG, CI Vice President, and one of the paper’s authors. “Through this process, we have learned a lot about what is working and what isn’t in sea turtle conservation, so now we look forward to turning the lessons learned into sound conservation strategies for sea turtles and their habitats.”

Five of the world’s 11 most threatened species of sea turtles are found in the northern Indian Ocean, specifically threatened populations of both Loggerhead Turtles (Caretta caretta) and Olive Ridley Turtles (Lepidochelys olivacea) are found in the northern Indian Ocean in waters and on nesting beaches within Exclusive Economic Zones (EEZs) of countries such as India, Sri Lanka and Bangladesh.. Other areas that proved to be the most dangerous places for sea turtles were the East Pacific Ocean (from the USA to South America) and East Atlantic Ocean (off the coast of western Africa).

“The report confirms that India is a home to many of the most threatened sea turtles in the world,” said Dr. B. C. Choudhury, head of the Department of Endangered Species Management at the Wildlife Institute of India and a contributor to the study. “This paper is a wake-up call for the authorities to do more to protect India's sea turtles and their habitats to ensure that they survive."

The study also highlighted the 12 healthiest sea turtle populations in the world, which are large and currently populations facing relatively low threats. Five species, such as the Hawksbill Turtle (Eretmochelys imbricata) and the Green Turtle (Chelonia mydas) have populations among these dozen thriving habitats which include nesting sites and feeding areas in Australia, Mexico and Brazil. Other areas that harbor healthy turtle populations include the Southwest Indian Ocean, Micronesia and French Polynesia.

“Before we conducted this study, the best we could say about sea turtles was that six of the seven sea turtle species are threatened with extinction globally,” said Dr Bryan Wallace, Director of Science for the Marine Flagship Species Program at CI, and lead author for the paper. “But this wasn’t very helpful for conservation because it didn’t help us set priorities for different populations in different regions. Sea turtles everywhere are conservation-dependent, but this framework will help us effectively target our conservation efforts around the world.”

Now that you have the bad news here is the good news. Below is a map of the 12 healthiest sea turtle populations. Both of these graphics are available on-line 


Friday, September 30, 2011

Which Species Will Survive Climate Change?

The speckled back salamander, one 
of the species studied could expand its current 
range (orange) into new territory (gray). 
Climate change, however will put new areas 
beyond the salamanders reach. Illustration 
Credit: Sax Lab, Brown University.

PROVIDENCE, R.I. [Brown University] — Species' ability to overcome adversity goes beyond Darwin's survival of the fittest. Climate change has made sure of that. In a new study based on simulations examining species and their projected range, researchers at Brown University argue that whether an animal can make it to a final, climate-friendly destination isn't a simple matter of being able to travel a long way. It's the extent to which the creatures can withstand rapid fluctuations in climate along the way that will determine whether they complete the journey.
   In a paper in Ecology Letters, Regan Early and Dov Sax examined the projected "climate paths" of 15 amphibians in the western United States to the year 2100. Using well-known climate forecasting models to extrapolate decades-long changes for specific locations, the researchers determined that more than half of the species would become extinct or endangered. The reason, they find, is that the climate undergoes swings in temperature that can trap species at different points in their travels. It's the severity or duration of those climate swings, coupled with the given creature's persistence, that determines their fate.
   "Our work shows that it's not just how fast you disperse, but also your ability to tolerate unfavorable climate for decadal periods that will limit the ability of many species to shift their ranges," said Sax, assistant professor of biology in the Department of Ecology and Evolutionary Biology. "As a consequence, many species that aren't currently of conservation concern are likely to become endangered by the end of the century."
   The researchers chose to study frogs, salamanders, and toads because their living areas are known and their susceptibility to temperature changes has been well studied. Based on that information, they modeled the migratory paths for each creature, estimating their travels to be about 15 miles per decade. The climate models showed fluctuations in temperatures in different decades severe enough that four creatures would become extinct, while four other species would become endangered at the least. The other seven would "fare OK," Early said, "but they all lose out a lot."
   The temperature swings can cause a species to be stopped in its tracks, which means that it has to do double time when the climate becomes more favorable. "Instead of getting warmer, it can get cooler," said Early, the paper's lead author, of the climate forecasts. "That means that species can take two steps forward, but may be forced to take one step backward, because the climate may become unsuitable for them. Unfortunately, if they take a step back, they have to make up all of that ground. That's what causes the gaps in the climate path."
   The study is unique also in that it considers at species' ability to weather adverse intervals. Early and Sax said unfavorable climate lasting a decade would put the species in a bind. If the interval lasted two decades or more, it was likely the species would become extinct. "We've identified one critical piece of information that no one's really thought about, and that is what's the ability of species to persist under non-optimal conditions," Sax said. "If you move to those conditions, can it hang on for a while? The answer will vary for different species."
   Rapid changes to climate already being witnessed underscores the study's value. A growing number of scientists believe climate change is intensifying so quickly that the planet is hurtling toward a sixth mass extinction in history — and the first widespread perishing of creatures since the dinosaurs' reign ended some 65 million years ago. For the first time, species are grappling not just with projected temperatures not seen for the last 2 million years but also with a human-shaped landscape that has compromised and fragmented animals' natural habitats.
   Confronted with these realities, Early and Sax say wildlife managers may need to entertain the idea of relocating species, an approach that is being hotly debated in conservation circles. "This study suggests that there are a lot of species that won't be able to take care of themselves," Sax said. "Ultimately, this work suggests that habitat corridors will be ineffective for many species and that we may instead need to consider using managed relocation more frequently than has been previously considered."

Citation
Early, R. and Sax, D. F. (2011), Analysis of climate paths reveals potential limitations on species range shifts. Ecology Letters. doi: 10.1111/j.1461-0248.2011.01681.x

New Frog Added to Trinidad's Herpetofauna

Scarthyla vigilans from southwest Trinidad. JCM
The tiny, grass-dwelling frog, Scarthyla vigilans (Hylidae) has been officially added to the herpetofauna of Trinidad. The frog avoided detection of previous researchers investigating the fauna of the continetal island until 2006 when J. Roger Downie and Joanna M. Smith collected striped tadpoles from an irrigation ditch in a coconut plantationin the southwest peninsula of the island. The tadpoles positioned themselves vertically in the water adjacent to submerged grass stems.The tadpoles did not match any of the known species from Trinidad.The tads weighed only 0.26 g and measured about 29 mm. Two adults were collected in 2007, and more were added in 2010. The frogs were discovered in Venezuela's Orinoco Delta in 2008, but the species was previously known from northeast Colombia and northwest Venezuela. The small size (14-19 mm) of adults, their very insect-like call, and their superficial similarity to the very common and widespread Scinax rubra has contributed to them going undiscovered. The full paper is available on-line.

Citation
Smith, J.M.; J.R. Downie; R.F. Dye; V. Ogilvy; D.G. Thornham; M.G. Rutherford; S.P. Charles; J.C. Murphy.2011. Amphibia, Anura, Hylidae, Scarthyla vigilans (Solano, 1971): Range extension and new country record for Trinidad, West Indies, with notes on tadpoles, habitat, behavior and biogeographical significance. Check List 7(5):574-577.

Thursday, September 29, 2011

Australian Tree Frogs Collect Condensation for Hydration

Research published in the October issue of The American Naturalist shows that Australian green tree frogs survive the dry season with the help of the same phenomenon that fogs up eyeglasses in the winter.

Christopher R. Tracy and colleagues found the Australian Green Treefrog, Litoria caerulea, remain active during the dry season with apparently no available water and at temperatures that approach their lower critical temperature. The authors hypothesized that when the frogs retreated to their refugia condensation forms on their cold skin — just like it does on a eye glasses or the widows of your car.  They used frogs retrieved from natural dens and artificial dens and found the frogs absorb the condensing moisture through their skin, to maintain hydration during periods of little or no rain.

Before this study, the frogs' dry-season excursions were a bit mysterious.

"Every once in a while, we would find frogs sitting on a stick under the open sky, on nights when it was so cold they could barely move," said Dr. Chris Tracy, who led the research. "It was a real puzzle."

Tracy and his colleagues thought this behavior might enable the frogs collect condensation, but the hypothesis had never been tested.

The researchers designed a series of experiments using real frog dens in eucalyptus trees and artificial ones made from PVC pipe. They wanted to see if the frogs could collect enough moisture through condensation to compensate for what they lost being in the cold. They found that a cold night out cost a frog as much as .07 grams of water. However, a frog could gain nearly .4 grams, or nearly 1 percent of its total body weight, in water upon returning to the warm den.

The researchers also tested how well a frog's skin could absorb water, and found that as much as 60 percent of each water drop could be absorbed.

The results show that frogs can use condensation to hydrate themselves. And in a place as arid as the Australian savannahs during the dry season, where there is essentially no rain from June through August, every little bit counts.

"When there's no water available, even a small amount can mean the difference between surviving the dry season or not," Tracy said.

Citation
Christopher R. Tracy, Nathalie Laurence, Keith A. Christian, 2011, Condensation onto the Skin as a Means for Water Gain by Tree Frogs in Tropical Australia." The American Naturalist 178:553-558.(October 2011)

Tuesday, September 27, 2011

MHC Genes Convey Resistance to Bd in Some Frogs

The BBC Science and Nature News is carrying this story by Richard Black. It comments on Bd research done at Cornell University by Anna E. Savage and Kelly R. Zamudio in an attempt to discover how amphibian populations might be best able to fight off the Bd fungus.

'Scientists have taken a big step toward understanding why some frogs survive the fungal disease chytridiomycosis while others quickly die.

A group from Cornell University, US, identified genetic factors that seem to make some individual frogs immune.

This could improve captive breeding schemes, the team writes in Proceedings of the National Academy of Sciences.

Chytridiomycosis is slowly spreading across the world, and has already sent a number of species extinct.

Just two years ago, researchers discovered how it kills - by damaging the skin so that key nutrients cannot pass through, resulting eventually in cardiac arrest.

Frogs and other amphibians that have no resistance succumb quickly, with some populations being extirpated in just a few weeks.

Yet some populations and some entire species survive intact, which has long perplexed researchers; and salamanders and caecilians (limbless amphibians bearing a superficial resemblance to earthworms or snakes) appear more resistant as groups than frogs - another mystery.


The Cornell group collected lowland leopard frogs (Lithobates yavapaiensis) from five places in Arizona.

"The study goes a long way toward understanding the genetic basis of resistance to the amphibian chytrid”

Reid Harris, James Madison University

In the lab, they infected the animals with the chytrid fungus (Batratochytrium dendrobatidis, or Bd).

All the frogs collected from three of the locations died; but from the other two locations, some survived, and fought off the infection completely within two weeks, remaining healthy.

The researchers traced the difference back to regions of DNA that form part of the immune system called the major histocompatibility complex (MHC).

Its role - in humans and other animals, just as in amphibians - is to "present" bits of invaders such as fungi or bacteria to other immune cells, identifying them as things that must be tackled.

"All amphibians (and for that matter, all vertebrate animals) have MHC genes that play the same 'gatekeeper' role in initiating immune responses," said lead researcher Anna Savage.

"So our finding that MHC genotypes contribute to chytridiomycosis outcomes has potential ramifications for all amphibian species currently threatened by Bd."

It appears likely that the two populations whose members survived infection in the lab are the ones that had been most strongly exposed to the fungus in the wild since it was detected in Arizona in the 1970s.

In this case, they probably carry the "resistant genes" because there has already been quite a lot of selection - only the strong have survived.

"It means frogs may have the evolutionary potential to adapt [to Bd]," Ms Savage told BBC News.

"Natural selection can only result in disease adaptation if genetic variation for that trait exists, and we have shown that it does."

The next step along this avenue of research is to find out whether the same thing provides immunity in other species - and whether it can explain why entire species such as the infamous cane toad survive Bd.

Then, conservationists will have to work out how the information can be used.

Ms Savage suggests a role in captive breeding programmes - the last resort for species that cannot remain in their native habitat because it is infested with chytrid.

Chytridiomycosis can kill amphibians in less than a week - depending on their genes
The idea would be to screen amphibians' MHC genes before breeding, to increase the odds of producing Bd-resistant tadpoles.

Prof Reid Harris, an amphibian specialist at James Madison University in Virginia who is trying to develop new treatments for chytrid, described the latest news as "very exciting".

"The study goes a long way toward understanding the genetic basis of resistance to the amphibian chytrid, and it opens up the possibility of selecting for resistance to the disease," he told BBC News.

"However, amphibian defences are multidimensional and include innate immune components and microbial defences.

"It is likely that a successful mitigation strategy will be multidimensional as well."

However, chytrid is only one of the many threats that amphibians face today.

The most profound is loss of habitat, as marshes are drained, forests cleared, and wild areas tamed for human use.

"Although our study provides a new hope that amphibians may bounce back from chytridiomycosis, it does not eliminate the need for human conservation efforts," Ms Savage stressed.

"Habitat loss, invasive species and habitat degradation are other major factors leading to amphibian declines; and if we can work to provide good habitats so that amphibian population sizes and genetic diversity can increase, they will be much more likely to have the genetic capacity to adapt to Bd."

Citation
Anna E. Savage and Kelly R. Zamudio 2011. MHC genotypes associate with resistance to a frog-killing fungus.PNAS Published online before print September 26, 2011, doi: 10.1073/pnas.1106893108

Ascension Island Sea Turtle Eggs Pre-Adapted For Warmer Temperatures

Photo Credit: Dr Sam Weber, University of Exeter
Ascension Island is one of those remarkable places on the Earth that serves as a reminder as to how the earth is constantly changing. The island sits on the mid-Atlantic Ridge. The place where the sea floor is being formed in the middle of the Atlantic and a point where Africa and South America were once joined to form the ancient continent of Gondwanaland. Today, the tiny island is used by diplomats, tourists, and most importantly sea turtles. The following is a press release about recent research on the island's sea turtles. The full article is available on-line.

Heat-proof' eggs help turtles cope with hot beaches 

Sea turtles face an uncertain future as a warming climate threatens to reduce their reproductive viability. However, new research led by the University of Exeter and published this week in Proceedings of the Royal Society B shows that some turtles are naturally heat-tolerant.

The study focused on green turtles nesting on Ascension Island, a UK overseas territory in the South Atlantic Ocean. Scientists from the Universities of Exeter and Groningen found that eggs laid by turtles nesting on a naturally hot beach withstand high temperatures better than eggs from turtles nesting on a cooler beach just a few kilometres away.
The warmer beach has dark sand, whereas the neighbouring beach is two to three degrees Celsius cooler because it has white sand. Green turtles travel from the coast of South America to the tiny island to nest. Most female turtles nest on the beaches where they themselves hatched, so populations can become adapted to specific nesting locations.

The researchers placed some of the eggs laid on each beach into incubators of either 32.5 degrees Celsius or 29 degrees Celsius and monitored their progress. They found that the eggs from the warmer beach were better able to thrive in the hot incubator than those from the cooler beach.

Dr Jonathan Blount, who led the research, said: "We believe this is the first time that adaptation to local environmental conditions has been demonstrated in sea turtles, which is all the more remarkable because the beaches in question are just six kilometres apart".

Heat-tolerant populations may be crucial in allowing species to adapt to a warming world, highlighting the need for conservation strategies which protect diversity in animal populations.

University of Exeter PhD student Dr Sam Weber, lead author of the study, said: "Such adaptations probably evolve over many generations, so whether turtle evolution can keep pace with the rapid climate change that scientists have predicted remains to be seen. However, occasional movements of heat-adapted turtles to other nesting sites could help to spread their favourable genes."

This research was funded by the Natural Environment Research Council, the Royal Society, the European Social Fund, Defra's Darwin Initiative and the Overseas Territories Environment Programme.

Citation

Sam B. Weber, Annette C. Broderick, Ton G. G. Groothuis, Jacqui Ellick, Brendan J. Godley, and Jonathan D. Blount 2011.Fine-scale thermal adaptation in a green turtle nesting population. Proc. R. Soc. B published online before print September 21, 2011, doi:10.1098/rspb.2011.1238

Sunday, September 25, 2011

Novel Squamates

In the 1970's I remember several conversations with zoo curators and reptile keepers who swore female snakes would give birth to offspring without ever being in the presence of a male or if they had been with a male it had been years before the offspring/eggs developed. The latter situation was often attributed to sperm storage. At the time, I was skeptical, but parthenogenesis was known in lizards since Ilya Darevsky discovered all female rock lizard, Lacerta saxicola, populations in 1958 in southern Russia. L. saxicola (Eversmann, 1834) has now been removed from Lacerta and placed in the genus Darevskia, with about 25 other species of rock lizards, the generic name derived from the name of the Russian herpetologist. But, four decades later parthenogenesis has been documented in many squamates, and it has apparently evolved at least 40 times independently. 
Squamate reptiles (lizards + snakes) are both numerous and diverse with 61 families and more than 9000 species. With the diversity come novel traits that have evolved multiple times - like parthenogenesis. In a forthcoming paper Sites et al. (2011) summarize many of these novel traits in squamates - traits like parthenogenetic, viviparity, limb-reduction and limb loss, herbivory, and venom. The authors note that squamates are the only vertebrate group with true parthenogenesis; the clade has more origins of viviparity than any other group of vertebrates; and squamates have undergone dramatic changes in body form (lizard-like to snake-like) dozens of times.

They also note that new phylogenetic hypotheses are challenge our ideas about squamate biology and are emerging at all taxonomic levels. Phylogeny based research is revealing much about ecological aspects of of parthenogenesis as well as finer details about the origins of several forms of viviparity.

Citation
Sites, J. W., Jr, T. W. Reeder, J. J. Wiens. 2011. Phylogenetic Insights on Evolutionary Novelties in Lizards and Snakes: Sex, Birth, Bodies, Food, and Venom. Annual Review of Ecology, Evolution, and Systematics, DOI: 10.1146/annurev-ecolsys-102710-145051

Thursday, September 22, 2011

Diverse Ecosystems May Reduce Threat From Bd

The Western Toad, Anaxyrus boreas.

Photo Credit: Ivan Phillipsen, OSU

The following is a press release from Oregon State University.

CORVALLIS, Ore. – Researchers at Oregon State University have shown for the first time that loss of biodiversity may be contributing to a fungal infection that is killing amphibians around the world – a finding that provides more evidence for why biodiversity is important to many ecosystems.

The research, being published this week in Proceedings of the National Academy of Sciences, used laboratory studies of amphibians to show that increased species richness decreased both the prevalence and severity of infection caused by the deadly chytrid fungus, Batrachochytrium dendrobatidis.

“With greater diversity of species, you get a dilution effect that can reduce the severity of disease,” said Catherine Searle, an OSU zoologist and lead author on the study. “Some species are poor hosts, some may not get infected at all, and this tends to slow disease transmission.

“This has been shown in other systems like Lyme disease which infects humans, mice and deer,” she said. “No one has really considered the dilution effect much in amphibians, which are experiencing population declines throughout the world. It’s an underappreciated value of biodiversity.”

It’s generally accepted, the researchers said, that a high diversity of species can protect ecosystem function, help to recycle nutrients, filter air and water, and also protect the storehouse of plant or animal species that may form the basis of medicines, compounds or natural products of value to humans.

Protection against the spread of disease should more often be added to that list, they said.

“Emerging infectious diseases are on the rise in many ecosystems,” said Andrew Blaustein, a co-author on this study, professor of zoology at OSU and leading researcher on the causes of amphibian declines.

“Protection of biodiversity may help reduce diseases,” he said. “It’s another strong argument for why diverse ecosystems are so important in general. And it’s very clear that biodiversity is much easier to protect than it is to restore, once it’s lost.”

The fungus, B. dendrobatidis, can lead to death from cardiac arrest when it reaches high levels in its amphibian hosts. It is not always fatal at lower levels of infection, but is now causing problems around the world. One research team has called the impact of the chytrid fungus on amphibians “the most spectacular loss of vertebrate biodiversity due to disease in recorded history.”

Amphibians face threats from multiple causes, including habitat destruction, pollution, increases in ultraviolet light due to ozone depletion, invasive species, and infectious disease.

The dilution effect can occur in plants and animals, but also in human diseases. In a different report published last year in Nature, researchers noted an increased risk of West Nile encephalitis in the U.S. in areas with low bird diversity. And in more diverse communities, the infection of humans by schistosomiasis – which infects 200 million people worldwide – can be reduced by 25-99 percent.


Citation
Catherine L. Searle, Lindsay M. Biga, Joseph W. Spatafora, Andrew R. Blaustein. A dilution effect in the emerging amphibian pathogen Batrachochytrium dendrobatidis. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1108490108

Wednesday, September 21, 2011

Where's Waldo, Final Answers


How do you like that, I'm on a computer that allows me to put little colored circles on pictures. Will miracles never cease? (they will if I go back to my old work computer) Makes identifying the area a little easier even if you still can't see the animal.
Best,
Marty

Ok Herpers,

My mommy used to tell me that if I kept playing with myself, I'd go blind.
So, I just did it until I needed glasses. It might be time for some of you to
find another hobby as well.

Marty Feldner got the last two teasers, which are attached.

All the crying that spewed on me as a result of this particular series
has me ready to convert my office into a saltwater aquarium. Would
any of the crabs out there in Suizo-land care to move in?

Sorry guys, but Stevie Wonder could have found that mud turtle.

What I've learned here, besides proper floor-mopping techniques,
is to just send one image at a time. Make the file size larger, and make
sure that at least part of the animal is visible. That way, you guys can cheat easier,
and you don't have to blow up a low resolution image to kingdom come and back while
you cry "foul."

That is my promise to you all for any future Where's Waldo installments.

Meanwhile, good show, Marty! We could use a few more good men like you around here.
HE didn't do any sniveling about it all--he was too busy DOING IT.

Love to all, and really, all in good fun. We'll play nicer from now on.

roger
Ok Herpers,
We're going with attachments with this one, as inserting images makes it harder
for you all to cheat. We don't want to make this any harder than it already is!

Pics 1 and 2: (Original Image #1 and "new" image revealing what and where):
For crying out loud you guys! Look in the little puddle. It's a Sonoran Mud Turtle.
They sometimes choose some very bad places to hide. Congrats to Jeff and Marty
for finding. Circle by Mr. Moorbeck.





Pics 3 and 4: (Original image # 2 and "new" image revealing what and where):
Sonoran Desert Tortoise. Circle by Jeff, Marty was on it as well.





Pics 5 and 6: (Original image #3 w/Jeff Circle added, and a closer look at snake):
Our newest addition to the Suizo Mountain Study, a Mojave Rattlesnake. Note
the heft on this rascal. Despite their reputation of being a nasty snake, this male
is a sweetheart! Honorable mention to Marty as well.





Pics 7 through 9: (Original image 4, plus two more hints).
I'm still not telling you where it is, but the angle of Pic 8 should give
it away. Pic 9 shows how well he hides. What is it, where is it? I do believe
Marty got this one, but couldn't identify the animal.








Pics 10 through 12: (Original image 5, plus 2 hints):
Where and what is the snake in Pic 10? You can't see it in Pic 10,
but Pics 11 and 12 clearly drop a bomb of a hint as to where it is.

Still looking for answers on original image 4 and 5.

One-two-three---GO!







8-) roger

Suizo Report -- Where's Waldo?

Howdy Herpers,

I think it best to send these images out this way.

In order to make the game a little more fair to you all, I removed the original image #3, and replaced it with the original image #6.

There are now 5 images. If you guys don't get 1 through 3 now, it's not my fault.

Images 4 and 5 are just plain mean on my part. I only send these again to show the hot shots that I DO know the difference between hard and easy.
And the second I show a little flank in any images (WOOHOO!), the hot shots will find the animal.

The game for all 5 is still the same. Name it and find it.






Best to all, roger