Wednesday, August 31, 2011

Okinawa Montane Viper Feeds During the Winter

Ovophis okinavensis. Photo Credit: 
Al Coritez.
The Okinawa Montane Viper, Ovophis okinavensis is a short, stout-bodied snake that inhabits forested areas, especially near streams, ponds, and marshes, in the subtropical Okinawa and Amami island groups in the Ryukyu Archipelago of Japan. The species is primarily terrestrial and nocturnal and is considered a typical ambush predator. Its diet consists of frogs, lizards, snakes, birds, and small mammals. Although this viper exhibits a generalized diet; however, the diet of some local populations is almost exclusively frogs. Previous ecological studies of O. okinavensis in the northern mountains of Okinawa Island suggested the species is most active from winter to early spring (December to March). And, those studies suggest that the activity pattern of the snake is closely associated with the breeding activities of frogs. Most snakes are active during the warmer parts of the year because they are ectotherms and rely on external heat  to maintain their body temperatures. Ovophis okinavensis is apparently an exception to this pattern. This unusual activity pattern may reflect the availability of prey, which obliges the snake to engage in feeding activities during periods of low temperatures. To test this hypothesis Kadota (2011) examined seasonal activity patterns of both O. okinavensis and the frogs in the study area. He found snake emergence corresponded with the emergence of frogs. The daily emergence of snakes was strongly correlated with that of frogs. These results suggest that O. okinavensis exhibits a foraging strategy that is adjusted to spatial and temporal fluctuations of the emergence of frogs. It would also be interesting to examine the impact of climate change on the behavior of this snake.

Citation: Kadota, Y. 2011. Is Ovophis okinavensis Active Only in the Cool Season? Temporal Foraging Pattern of a Subtropical Pit Viper in Okinawa, Japan.  Zoological Studies 50:269-275.

Tuesday, August 30, 2011

The Impact of Climate Change on Four Species of Snakes

Bitis nasicornis. JCM

The prediction that climate change will have dramatic impacts on organisms has been discussed for a while. Three new studies support the idea that climate change will greatly influence snakes and how they will adjust to changes in habitat, competitor abundance and changes in the available food supply. These changes are occurring now and will continue into the future. 

Pierluigi Bombi and colleagues have two papers (Bombi et al. 2011a,b). In the first they report (Bombia 2011a) that the most endangered snake in Italy, the Sardinian Whipsnake, Hemorrhois (= Coluber) hippocrepis, is threatened by human alteration of its habitat and suggest that this is exacerbated by climate change. In Italy, the species in known only from the southern end of Sardinia. While nothing is known about the potential effects climate change could exert on this species, ecological modeling of its habitat suggested climate changes will greatly alter the snake's remaining habitat. Changing climate conditions will cause a dramatic reduction of suitable habitat by 2020, with a further collapse by 2050 (down to 11 km2). They found only one existing protected area will likely retain suitable habitats for this species.

In a second article, Bombi et al. (2011b) used data collected over the past 15 years on the ecology and population abundance of the Gaboon viper (Bitis gabonica) and the Nose-horned Viper (Bitis nasicornis) in southern Nigeria. The field work found several high-abundance and low-abundance populations of these two species. The authors analyzed the potential effects of climate change by modeling the current dataset on viper abundance (both high and low) using generalized additive models. Using climatic surfaces of current conditions as spatially explicit predictors, they projected viper abundance into a future climatic scenario. The future climatic conditions seemed appropriate for the success of the climatic niche used by the high-abundance Gaboon viper in their study area. While the future climatic niche for the high-abundance nose-horned viper populations was predicted narrow. In future scenarios, the two species were predicted to have a larger overlap in their climatic niche, and this is likely to increase interspecific competition.

Beata Ujvari at the University of Wollongon and colleagues (2011) note that climate change can result in the movement of resources critical for the viability of a population, and a species' resilience to such changes will depend upon its ability to shift its activities away from no-longer-suitable sites to exploit new opportunities. Common sense would suggest that predators should be able to track spatial shifts in prey availability, but data on water pythons (Liasis fuscus) in tropical Australia suggest a less encouraging scenario. Water Pythons undergo seasonal migrations that may cause them to move up to 10 km, following flooding-induced migrations by their prey, the Native Dusky Rats (Rattus colletti). However, when an extreme flooding event virtually eliminated the rats for three years, the local pythons did not disperse despite the presence of abundant rats only 8 km away; instead, many pythons starved to death. This inflexibility suggests species that track seasonally migrating prey may do so by responding to habitat attributes that have consistently predicted prey availability over evolutionary time, rather than reacting to proximate cues that signal the presence of prey per se. Therefore, a species' vulnerability to climate change will be increased by an inability to shift its activities away from historical sites toward newly favorable areas.

Literature

Bombi, P.and Capula, M., Amen, M and Luiselli, L.. 2011a.Climate change threatens the survival of highly endangered Sardinian populations of the snake Hemorrhois hippocrepis. Animal Biology 61:239-248.
Bombi, P., Akani, G. C., Ebere, N., Luiselli, L. 2011b. Potential effects of climate change on high- and low-abundance populations of the Gaboon viper (Bitis gabonica) and the nose-horned viper (B. nasicornis) in southern Nigeria. The Herpetological Journal 21:59-64.

Ujvari, B., Shine, R., Madsen, T.. 2011. How well do predators adjust to climate-mediated shifts in prey distribution? A study on Australian water pythons. Ecology 92:777–783. [doi:10.1890/10-1471.1]

Monday, August 29, 2011

Daphnia Feed on Bd: Can this Save Frog Species From Extinction?

Researchers have confirmed that this
zooplankton, Daphni magna, will eat
a deadly fungus that is devastating
amphibian populations around the world.
 It may provide a new biocontrol agent
to help address this crisis. (Photo
Credit:Oregon State University)
Zoologists at Oregon State University have discovered that a freshwater species of zooplankton will eat a fungal pathogen which is devastating amphibian populations around the world.

This tiny zooplankton, called Daphnia magna, could provide a desperately needed tool for biological control of this deadly fungus, the scientists said, if field studies confirm its efficacy in a natural setting.

The fungus, B. dendrobatidis, is referred to as a "chytrid" fungus, and when it reaches high levels can disrupt electrolyte balance and lead to death from cardiac arrest in its amphibian hosts. One researcher has called its impact on amphibians "the most spectacular loss of vertebrate biodiversity due to disease in recorded history."

The research, reported August 26 in the journal Biodiversity and Conservation, was supported by the National Science Foundation.

"There was evidence that zooplankton would eat some other types of fungi, so we wanted to find out if Daphnia would consume the chytrid fungus," said Julia Buck, an OSU doctoral student in zoology and lead author on the study. "Our laboratory experiments and DNA analysis confirmed that it would eat the zoospore, the free-swimming stage of the fungus."

"We feel that biological control offers the best chance to control this fungal disease, and now we have a good candidate for that," she said. "Efforts to eradicate this disease have been unsuccessful, but so far no one has attempted biocontrol of the chytrid fungus. That may be the way to go."

The chytrid fungus, which was only identified in 1998, is not always deadly at low levels of infestation, Buck said. It may not be necessary to completely eliminate it, but rather just reduce its density in order to prevent mortality. Biological controls can work well in that type of situation.

Amphibians have been one of the great survival stories in Earth's history, evolving about 400 million years ago and surviving to the present while many other life forms came and went, including the dinosaurs. But in recent decades the global decline of amphibians has reached crisis proportions, almost certainly from multiple causes that include habitat destruction, pollution, increases in ultraviolet light due to ozone depletion, invasive species and other issues.

High on the list, however, is the chytrid fungus that has been documented to be destroying amphibians around the world, through a disease called chytridiomycosis.

Its impact has been severe and defied various attempts to control it, even including use of fungicides on individual amphibians. Chytridiomycosis has been responsible for "unprecedented population declines and extinctions globally," the researchers said in their report.

"About one third of the amphibians in the world are now threatened and many have gone extinct," said Andrew Blaustein, a professor of zoology, co-author on this study and an international leader in the study of amphibian decline.

"It's clear there are multiple threats to amphibians, but disease seems to be a dominant cause," he said.

Although they have survived for hundreds of millions of years, amphibians may be especially vulnerable to rapid environmental changes and new challenges that are both natural and human-caused. They have a permeable skin, and exposure to both terrestrial and aquatic environments.

Because of this, OSU researchers said, other animals such as mammals, birds and fish have so far not experienced such dramatic population declines

Original Citation
Julia C. Buck, Lisa Truong, Andrew R. Blaustein. Predation by zooplankton on Batrachochytrium dendrobatidis: biological control of the deadly amphibian chytrid fungus? Biodiversity and Conservation, 2011; DOI: 10.1007/s10531-011-0147-4

Sunday, August 28, 2011

Female Taiwanese Kukrisnakes Defend Territories Around Sea Turtle Nests

Oligodon formosanus. Photo courtesy

of Hans Breuer, and Snakes of Taiwan.

Kukrisnakes of the genus Oligodon are specious, with 69 species currently recognized, but poorly studied species. Although, several of them have been reported to feed on the eggs of other reptiles. Huang and colleagues (2011) report territorial behavior in the Taiwanese Kukrisnake (Oligodon formosanus). Territorial defense of an area containing resources (such as food or shelter) is widespread in lizards but poorly documented in snakes. The authors found the insland population of Oligodon formosanus have females that actively defend sea turtle nests by repelling other snakes of the same species for long periods (weeks) until the turtle eggs hatch or are consumed. A clutch of turtle eggs comprises a large, long-lasting food resource, unlike the prey types exploited by other types of snakes. Kukrisnakes of this species have greatly enlarged teeth that are used for slitting eggshells, and when threatened, these snakes wave their tails toward the aggressor (an apparent case of head-tail mimicry). Bites to the tail during intraspecific combat bouts thus can have high fitness costs for males should the hemipenes be damaged. In combination, unusual features of the species (ability to inflict severe damage to male conspecifics) and the local environment (a persistent prey resource, large relative to the snakes consuming it) render resource defense both feasible and advantageous for female kukrisnakes. When males arrived first, and outnumbered females, all of the turtle eggs in a nest were consumed rapidly (in three nests where we had accurate records of snake arrival and departure, all snakes departed within 5 days, no new snakes entered the nest after that time, and excavation of these nests confirmed that all eggs had been consumed). As soon as female snakes arrived at a nest, the authors saw other snakes being forcefully expelled (rapid retreat, sometimes with fresh wounds). Males that had been expelled often remained nearby and tried to reenter nests. The probability that a late-arriving male would remain within a nest was lower if a female snake was already present in the nest than if no female snakes were present in the nest. The (apparently unique) evolution of territorial behavior in this snake species thus provides strong support for the hypothesis that resource defensibility is critical to the evolution of territoriality.

Citation
W.-S. Huang, H. W. Greene, T.-J. Chang,and R. Shine 2011. Territorial behavior in Taiwanese kukrisnakes (Oligodon formosanus). Proc Natl Acad Sci. 108:7455–7459.

Snake Venom Smugglers

Stories in the Malaysia National News Agency, Bernama.Com and the Deccan Chronicle are reporting snake venom smugglers are apparently extracting venom glands from snakes and leaving the snakes to die. Wildlife officials suggest the activity is done in remote areas by well organized syndicates. Illegal venom smuggling surfaced in Kerala and Orissa this week. The venom is used not only in the production of antivenom, but also as an aphrodisiac and is sold to snake charmers. Kedar Swain, a Balasore Forest Division officer, has a team who arrested five smugglers and seized 48 venomous snakes last week. The suspects were trying to sell the venom in Kasargod in the northern tip of Kerala. The suspectes were said to have had vipers, cobras, and a liter of venom.

Saturday, August 27, 2011

Suizo Report -- The "Other" BOR Gathering

Well, Herpers, 22 August 2011

The Biology of Rattlesnakes Conference (BOR) is now a month past. My reasons for not attending were many, and complicated. But the reason that sealed the deal of my non participation was the complete lack of vacation time in my hopper. No time off, no conference, end of story.

But I did use the weekends before and after the conference to entertain visiting dignitaries, as well as solid local friends. Unfortunately (for them), most incoming geeks did not plan on using the weekend before the event as herping time. Most arrived for the Wednesday icebreaker. Hence, they paid the severe penalty of going Rogerless for round one of the action. Let what follows be a lesson to the lot of them.

Image 1, below: Saturday, 16 July. Bernd Skubowins (left) rolls into town and joins Young Cage (right) and I for a trip to black velvet land. Bernd was visiting from Germany, and is a big fan of the pinesnake/gophersnake clade. He came to Arizona last year in September, and had zero luck seeing his first wild gophersnake. While gophersnakes are not difficult to encounter in this region, they become next to impossible to find when one is looking for them.
Image 2: All totaled, we found thee Arizona Black Rattlesnakes the morning of 16 July. The first one was the best. It was a big, beautiful orange and black male viewed basking coiled in the shade of a mighty oak tree, next to a deep-running soil hole that entered the tree at the base of some exposed roots. I know that the hole was deep, because before we could react, the snake promptly plunged into it, and we could hear the rattle singing merrily as it blazed to all the way to China.

Bernd found the next one coiled next to a downed log, with yet another deep running hole directly behind it. We were considerably more wary with this one. Young yanked it with his snake tongs for some staged photos. The snake was released at his place of capture when we were done. He was still sitting in the capture spot an hour later when we checked on him. A week later, a shed skin was observed in the deep hole where the snake had been poised. (Image by Bernd).

Image 3: Bernd also found the last cerberus of the day. At this point in the day, it was 37 C (98.6 F)­and we still had a long, hot hike back to the vehicle.
The ride into and out of the area has a high probability for a gophersnake encounter. Needless to say, we didn’t see any!

That evening, we joined Young again for a cruise of his sanctuary in the Tortolita Mountains, just north of Tucson. While Young was disappointed with the results, it was hard for me to bitch about the lyresnake pictured below: 

 And there is always great rejoicing when a Gila Monster crosses my path: 

As I had to get up early the next morning for a plot visit, Young dropped me off at my truck, and Bernd and he went on to find a saddled leaf-nosed snake. As I have not seen one of these in two years, I did feel some remorse over missing it. But poor Young was close to throwing himself on a sword. He has been spoiled by some of the best road cruising that Tucson has to offer. He felt that the evening was a bust.

C’mon out with me sometime Young. I’ll show you a bust!

The next night (17 July), Bernd and I took a drive out into the flats northwest of the Tortolita Mountains. Just as darkness was descending, we caught a glimpse of a snake sprawled on the shoulder of a paved road. We stopped, ran it down, and what do you think it was? We finally popped a gophersnake for Bernd (Image by Bernd):

In addition to the gophersnake, we scored seven sidewinders. This evening assured that I would beat my miserable total of 11 sidewinders last year. This excellent image of one of the seven was done by Bernd: 


We scored a war-wounded lyresnake close to my house at the end of the evening, which rolled over and died during our attempts to photograph it. No sense in showing an image of a writhing, dying lyresnake. After this evening, Bernd disappeared in a blaze of herping anywhere and everywhere with everybody but me. Thus endeth Bernd for the remainder of the week under discussion.

My next outing was the evening of 21 July. Jeff Smith and I met Mike Dloogatch and Linda Malawy, both of Chicago Herpetological Society fame, in the lobby of the hotel where the conference was held. Mike, Linda and Jeff were not quite in a state of readiness when I arrived. This allowed me 45 minutes time to be assailed by a crazed mob of rattlesnake aficionados, several of whom wanted to know where all the sweet spots around Tucson are. Yeah, sure, let me reveal all the honey holes to you guys, and then I can just go find new places. By the time we left the place, I was having a gushing man period. No small amount of time was spent reminding my companions of the finer nuances of the big hands and little hands on watches. The grousing continued for quite a duration, until Linda lightened things up a bit by saying how much she appreciated the efforts of the Border Patrol to keep our area safe. It must have been the fifty or so Border Patrol vehicles zooming all around us that inspired this comment. She even went on to say that she intended to send them a thank you note for all they do.

A thank you note? To the Border Patrol? Goodness gracious! Yeah­I’d like to send them a little note as well. But my note would surely insert a different accolade in front of the word “you.”

Thank you notes? To the Border Patrol? Jeez……….

The road we selected this night was, at one point, my own private sanctuary. But on this night, we shared it with two other vehicles jammed with people who were attending the conference. Yup, good idea! Let’s bring 200 plus herpers into our area, so that they can muck it up for those of us who pay our dues all year long. There was no hot surge of joy when these other herpers told us stories of lyresnake, tiger rattlesnake, and Gila Monster encounters. We had to make do with two black-tailed rattlesnakes, of which the one pictured below was the best: 

Mr. Dloogatch, Ms. Malawy, c’mon back sometime when the numbers of herpers are less-than-legion. We’ll have a quieter, more productive time, I’m sure.

On 23 July, the last day of the conference, we were able to coerce some of our visitors to ditch the geek gathering, and come out to play with us. Thus it came to pass that the following people, moving left to right in the image below, got together for some herping: Tying Boy, Ryan Sawby, Hans-Werner Herrmann, Harry Sweet, visiting Swedes Mats and Karl Hoggren, Gordon Schuett, and visiting Texan, Bill Montgomery. 

Our mission was to score an Arizona black rattlesnake, so we headed right back to the same canyon that Bernd, Young and I had visited the previous week. The first find of the day was the large adult black-necked gartersnake viewed in the image below. I was so thrilled with Ryan’s find that I didn’t even double back to look at it. But I am grateful that Bill took the time to photograph it for us: 

Following that adventure in mediocrity, it was “Typing Boys” turn to score. I spotted a large adult male black rattlesnake coiled among leaf litter, next to a hole that led under a downed sycamore tree. While trying to get an image of the snake peacefully coiled in situ, it suddenly spooked, rattled, and bolted toward the hole. The lesson of the quick escape of the big cerb the week previous was not lost on me This time, I was on it like scum on a pond, snagged it with my Whitneys, and hauled it out into a clearing. I next deliberately placed myself between it and the hole it was seeking. And WHOA BABY!! I’ve seen many snakes go ballistic when cornered, but this was the most aggressive snake that I’ve ever faced. It was launching lightening fast knee-high strikes at me as it came on. At first, all it was trying to do was get around me­or through me, in order to get to shelter. After several minutes of this, all it wanted was a piece of me. While I was thwarting lunge-after-lunge with my snake tongs, my gullet was alternating between bellowing “CERBERUS!” and making little mewing sounds of absolute terror. The intensity of the fight in this snake was a dreadful thing to behold. Finally, Harry showed up to assist, and the two of us finally got it calmed down enough to get some images. One by one, the herpers began trickling in to the scene. The stock in batteries and memory cards must have risen sharply, and the shaded arena that the snake made its stand was well lit by the strobe-light effects of flash photography ensuing from all angles. Of all the shots to pass before my eyes of this very cool viper, the Bill Montgomery image that falls below ranks as my favorite: 
A gorgeous but very nasty snake!

Following this find, it was noticed that this cohort of herpers was cohesive, diligent, and dedicated. They wove a herpetological tapestry under a canopy of oaks, sycamores, and walnut trees, scouring escarpments under root systems, crawling over and around boulders, and fanning out in such a way that nobody violated another’s space. This group was definitely A-Team material, and I will herp with this group again any time that we can pull them together. Despite their well-exectued effort, a long period of finding nothing transpired.

Eventually, we reached a turn-around point. From the second it was ascertained that it was time to head back, the scent of beer was wafting in my nostrils. When it was noted that the habitat-infested stream that the A-Team was following was well-manned, it was determined that being the first one to the cooler was my main purpose in life. At the point where the stream makes a wide-sweeping bend, I made for a short cut that leads one over open ground, cutting 200 meters of rugged footwork out of the hike. As I blazed across the sparsely-vegetated, flat, featureless and highly over-grazed ground before me, the only thing on my mind was an ice-cold beer. Who would have thunk that somebody focused on such errant thought patterns would be the one to find the last cerberus of the morning?

But just as sure as $hit clings to a bedsheet, a sweet, sweet wayward female cerberus that had no business whatsoever crossing the open ground before me proceeded to do so. If anybody can find the easy ones­it’s me! It was the Roger Repp show today! I hang with such good herpers these days that it is never the Roger Repp show any more. And while I am always pleased to be the recipient of $hithouse luck, I would have much preferred that one of the visiting dignitaries--who were trying so hard, be the person to score. But that just wasn’t in the cards today.

And so, the hollering started, and once again, Harry was the first to join me. But this time, all we had to do was follow the retreating snake at a safe distance. She had nowhere to run, and nowhere to hide. She eventually made her stand by coiling against the trunk of a scrubby mesquite tree. The gathering of geeks ensued, and much adieu over nothing transpired. As one who looks critically at every image I receive, without bias, I do believe that nobody else did this snake more proud than I. See image below: 

Whereas the first cerberus of the day was an absolute pistol, this one was pure sweetness and honey. We made several efforts to get her to display her rattle by gently trying to hook them out of the coils. As soon as we would get them out, she would pull them back in. As I was the main hook operator, Bill eventually felt inspired to inform me “She ain’t gonna show you her tail, Roger. This here is a decent lady.” Despite the chivalrous comment, Bill was quick enough on the trigger to deliver the best image of our lady showing us her stuff (and she is a bit modest­eh?):


We eventually made it back to the vehicles, and headed for a place that I call “Windy Knoll.” This place affords the shade of a majestic oak tree, which in turn is perched on top of a small, otherwise open hillside. The spot is aptly named, as its location puts it in the wind, so to speak, and also affords a stunning view of the vistas of the Rincon and Little Rincon Mountains. The puddle viewed in the image below was absolutely alive with the tadpoles of spadefoot toads: 

The last treat of the morning, as if we needed any other, was found on the road out: 

We took the rest of the day off, and reconvened at my house at 1800, choked down some pizza, and headed off for the Suizo Mountain Study Plot. Harry dropped out of the picture for this adventure, and Melissa Amarello and Jeff Smith joined us. All totaled, nine people hit the plot with all they had. But it was the Jeff and Melissa show all the way. Their first worthy find of the night was this DANDY lyresnake (image by Mats Hoggren): 


And, as mentioned in an earlier report, a new tiger rattlesnake for the plot (Mats Hoggren):

The road out led us to many more cool finds, such as this gorgeous little gophersnake:

Three of these (Bill Montgomery):
And finally, three of these (Mats Hoggren):


And now, it is all behind us. One full week of hard hitting herping and fun. I heard many wonderful things about the Biology of Rattlesnakes conference. I'm sorry to have missed it. But I know for sure that our own little Biology of Rattlesnakes gathering was also a great adventure in learning, friendship, and adventures. As always, we look forward to whatever comes next.

Best to all, roger

Saturday, August 20, 2011

The Eastern Yellow-bellied Racer in Saskatchewan

Photo Credit: Laura Gardiner
The following story is being carried by the CBC, Canada.

Wet weather in Saskatchewan is creating trouble for a dwindling population of racer snakes.

Their winter home, a den in the Grasslands National Park in the province's southwest, was hit with heavy rain last year and this spring, turning the site into a soggy and largely inhospitable mess.

The eastern yellow-bellied racer is the focus of study for University of Regina student Laura Gardiner.

"It looks like a big crater," Gardiner said, in describing the damage done to the snake pit. "The soil has just collapsed or slumped."

Gardiner said the damage is so severe some snakes were trapped in the pit and could not emerge from their winter hibernation.

To make matters worse, spring rains led to a second slump at the pit and those snakes that did manage to make it out will have difficulty finding an open route to take them below the frost line for this winter's hibernation.

Gardiner notes the den is home to a number of species of snakes, including racers and rattlesnakes.

"Eastern yellow-bellied racers are a threatened species already in Canada," she said. The Grasslands park had the largest known snake pit.

"What the slump has done is prevented the snakes from the coming out and likely caused death for some of those snakes," she said.

As part of her research, Gardiner has been tracking the snakes using micro-chip technology.

According to her calculations, in 2010 there were more than 300 racers at the Grasslands snake pit. The estimate for 2011 is about 150 snakes.

"It was a bit of a shocker," Gardiner said, in assessing the impact the slumps have had on the snakes. "These snakes are already threatened so it was a big blow to the biggest population we know of in Canada."

She said work is now underway to see if the eastern yellow-bellied racer has established itself elsewhere.

There have been unconfirmed sightings in the Cypress Hills.

"What we're trying to do is find out if they actually are as rare as we thought," Gardiner said. "And if they're not, then maybe this blow to the population at the snake pit wasn't as significant as we thought, hopefully."

It won't be an easy task, she said, explaining that the yellow-bellied racer is an elusive creature.

"They're hard to find," she said, but added that with the concern about the numbers, researchers will be looking harder than ever for the snake.

Laura Gardiner has been studying the eastern yellow-bellied racer snake and its winter hibernation pit in the Grasslands National Park. Photo courtesy Laura GardinerTo

Friday, August 19, 2011

Researchers Complete First Major Survey of Amphibian Fungus in Asia

Rana similis, a frog species found in the Philippines.
The survey conducted by Vance Vredenburg and
colleagues found that this species has one of the
highest infection levels of the chytrid fungus in Asia
 and is potentially threatened by the disease. Photo
Credit: R. Brown, University of Kansas.

An international team of researchers has completed the first major survey in Asia of a deadly fungus that has wiped out more than 200 species of amphibians worldwide. The massive survey could help scientists zero in on why the fungus has been unusually devastating in many parts of the globe -- and why Asian amphibians have so far been spared the same dramatic declines.

The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis or Bd, is the culprit behind amphibian extinctions in Central, South and North America, Australia and Europe. The new Asian survey of the fungus, which was published Aug. 16 in the journal PLoS One, shows that Bd is prevalent at very low levels in the region.

Asia is home to a highly diverse set of amphibian species, and potentially could be vulnerable to Bd. But Vance Vredenburg, assistant professor of biology, said very little is known about the fungus and its impact on the health of amphibians in Asia.

"That's why we're excited about this first really big survey," said Vredenburg, who led the research team. "If you look at chytrid worldwide, Asia's been the black hole in our data."

From 2001 to 2009, Vredenburg and his colleagues surveyed more than 3,000 amphibians -- mostly frogs -- from 15 Asian countries, swabbing the toe webbing, thigh and abdomen of the animals to pick up any signs of Bd, which infects the skin of amphibians.

They found that the prevalence of Bd was very low throughout the region, appearing in only 2.35 percent of the frogs. The Philippines, Kyrgyzstan, Laos, Indonesia, Malaysia and South Korea were the only countries with any Bd infection.

The survey suggests that Bd is either emerging in Asia, or may have been in Asia at low levels for a long time or that some other factor is preventing Bd "from fully invading Asian amphibians," the researchers write.

Each site in the study was only surveyed once, Vredenburg explained, so it's difficult to determine whether Bd infections in the countries are newly expanding. It will be critical, he said, "to see how Bd prevalence is changing through time, because this is key to understanding the ultimate outcome of the disease."

If Bd has been in Asia for a long time, researchers would like to know why amphibians there have managed to co-exist with a fungus that has proved so destructive elsewhere. It is possible, for instance, that Asian amphibians might bear some sort of bacterial protection against Bd in their skins.

Other scientists are analyzing the genes of the Bd fungus collected globally, Vredenburg said, "to find out whether strains from different parts of the world also differ in their virulence."

Vredenburg said the possibility of another wave of extinctions highlights the need to follow the Asian survey with further research to answer all of these questions.

And if Asia is on the brink of a chytrid epidemic, Vredenburg and colleagues think it might start in the Philippines. "The prevalence and intensity of Bd infection is much higher here than anywhere else in Asia," he said. "Bd in the Philippines today looks similar to Bd in early outbreaks in California and South and Central America."

"This study is the first important step to understanding Bd in Asia," Vredenburg said. "It provides a solid foundation that future studies can build upon."

Link to Original Article: Swei A,  et al. (2011) Is Chytridiomycosis an Emerging Infectious Disease in Asia? PLoS ONE 6(8): e23179. doi:10.1371/journal.pone.0023179

Cane Toad Tadpole Cannibalism

Rhinella marina. JCM
Most tadpoles eat almost anything, they filter the substrate and water for organic mater taking in bacteria, decomposing matter, mud, and other kinds of molecules they can get energy from. The Marine Toad or Cane Toad as the Australians call them have tadpoles that have very flexible diets. A forthcoming article in Animal Behaviour reports Rhinella marina tadpoles will eat the eggs of their own species. The BBC is reporting on this article, and the original article can be found here.

Cane toad tadpoles cannibalise eggs to survive, and the behavior starts when they are just a few days old.It is a habit that reduces competition and provides the cannibals a nutritional boost.

"Toad tadpoles almost never encounter eggs that are closely related to them - so they can happily go ahead and munch any they find” says Professor Richard Shine, University of Sydney. Researchers from the University of Sydney and James Cook University, Queensland in Australia, wanted to find out why cane toad tadpoles ate the eggs of their own species.

Their study compared two groups of tadpoles, one group was allowed to eat toad eggs and the other was prevented.

The team found that cannibal tadpoles survived, grew and metamorphosed into toads more successfully than the tadpoles that did not eat the eggs.

Although the tadpoles benefited from the nutrition of the eggs, they also improved their chances for the future, according to Professor Richard Shine who lead the research.

"The most important benefit is not nutrition, but the reduction of competition from the tadpoles that otherwise would have hatched from those eggs," he said.

But the tadpoles' voracious appetites do not extend to their siblings, as Prof Shine explained.

"The tadpoles don't eat close kin eggs, because of the short incubation period and the long delay between successive clutches by a single female," he told BBC Nature.

"Thus, toad tadpoles almost never encounter eggs that are closely related to them - so they can happily go ahead and munch any they find, without the risk that they are eating their relatives."

Proffesor Shine's results build on his previous findings that cane toad tadpoles can detect eggs in a pond using their sense of smell.

"Toad tadpoles can use specific chemicals produced by toad eggs to locate those eggs and eat them," he explained.

"We were astonished to discover that these simple little creatures, with brains the size of a pinhead, can react in subtle ways to specific cues.

"The tadpoles have a secret chemical language that only they can detect and respond to."

Cane toads are native to South America but were introduced to Australia in 1935 to control sugar cane pests.

Original Article
Michael R. Crossland, Mark N. Hearnden, Ligia Pizzatto, Ross A. Alford and Richard Shine. 2011.Why be a cannibal? The benefits to cane toad, Rhinella marina [=Bufo marinus], tadpoles of consuming conspecific eggs. nimal Behaviour, In Press, Corrected Proof, Available online 9 August 2011.

Further, faster, higher: wildlife responds increasingly rapidly to climate change

New research by scientists in the Department of Biology at the University of York shows that species have responded to climate change up to three times faster than previously appreciated. These results are published in the latest issue of the leading scientific journal Science.

Faster distribution changes. Species have moved towards the poles (further north in the northern hemisphere, to locations where conditions are cooler) at three times the rate previously accepted in the scientific literature, and they have moved to cooler, higher altitudes at twice the rate previously realised.

These changes are equivalent to animals and plants shifting away from the Equator at around 20 cm per hour, for every hour of the day, for every day of the year

Analysing data for over 2000 responses by animal and plant species, the research team estimated that, on average, species have moved to higher elevations at 12.2 metres per decade and, more dramatically, to higher latitudes at 17.6 kilometres per decade.

Project leader Chris Thomas, Professor of Conservation Biology at York, said: “These changes are equivalent to animals and plants shifting away from the Equator at around 20 cm per hour, for every hour of the day, for every day of the year. This has been going on for the last 40 years and is set to continue for at least the rest of this century. ”

The link to climate change. This study for the first time showed that species have moved furthest in regions where the climate has warmed the most, unambiguously linking the changes in where species survive to climate warming over the last 40 years.

First author Dr I-Ching Chen, previously a PhD student at York and now a researcher at the Academia Sinica in Taiwan, said: “This research shows that it is global warming that is causing species to move towards the poles and to higher elevations. We have for the first time shown that the amount by which the distributions of species have changed is correlated with the amount the climate has changed in that region.”

Co-author Dr Ralf Ohlemüller, from Durham University, said: “We were able to calculate how far species might have been expected to move so that the temperatures they experience today are the same as the ones they used to experience, before global warming kicked in. Remarkably, species have on average moved towards the poles as rapidly as expected.”

A diversity of changes. These conclusions hold for the average responses of species, but individual species showed much greater variation. Some species have moved much more slowly than expected, others have not moved, and some have even retreated where they are expected to expand. In contrast, other species have raced ahead, perhaps because they are sensitive to a particular component of climate change (rather than to average warming), or because other changes to the environment have also been driving their responses.

Co-author Dr David Roy, from the Centre for Ecology & Hydrology, illustrates this variation among species: “In Britain, the high brown fritillary butterfly might have been expected to expand northwards into Scotland if climate warming was the only thing affecting it, but it has in fact declined because its habitats have been lost. Meanwhile, the comma butterfly has moved 220 kilometres northwards from central England to Edinburgh, in only two decades.”

Similar variation has taken place in other animal groups. Cetti’s warbler, a small brown bird with a loud voice, moved northwards in Britain by 150 kilometres during the same period when the Cirl bunting retreated southward by 120 kilometres, the latter experiencing a major decline associated with the intensification of agriculture.

How they did the research. The researchers brought together all of the known studies of how species have changed their distributions, and analysed them together in a “meta-analysis”. The changes that were studied include species retreating where conditions are getting too hot (at low altitudes and latitudes), species expanding where conditions are no longer too cold (at high altitude and latitudes), and species staying where they are but with numbers declining in hotter parts and increasing in cooler parts of the range.

They considered studies of latitudinal and elevational range shifts from throughout the world, but most of the available data were from Europe and North America.

Birds, mammals, reptiles, insects, spiders, other invertebrates, and plants featured in the evidence. For example, I-Ching Chen and her colleagues discovered that moths had on average moved 67 metres uphill on Mount Kinabalu in Borneo.

Co-author Jane Hill, Professor of Ecology at York, said: “We have taken the published literature and analysed it to detect what the overall pattern of change is, something that is not possible from an individual study. It’s a summary of the state of world knowledge about how the ranges of species are responding to climate change. Our analysis shows that rates of response to climate change are two or three times faster than previously realised.”

Implications. The current research does not explicitly consider the risks posed to species from climate change, but previous studies suggest that climate change represents a serious extinction risk to at least 10 per cent of the world’s species. Professor Thomas says: “Realisation of how fast species are moving because of climate change indicates that many species may indeed be heading rapidly towards extinction, where climatic conditions are deteriorating. On the other hand, other species are moving to new areas where the climate has become suitable; so there will be some winners as well as many losers.”

Original Article:
I.-C. Chen, J. K. Hill, R. Ohlemuller, D. B. Roy, C. D. Thomas. Rapid Range Shifts of Species Associated with High Levels of Climate Warming. Science, 2011; 333 (6045): 1024 DOI: 10.1126/science.1206432

Wednesday, August 17, 2011

Species Believed Extinct Rediscovered, Hope for Biodiversity

Extinction is a focal issue among scientists, policy makers and the general public. Each year, numerous species which are thought to have disappeared are rediscovered. Yet, these rediscoveries remain on the brink of extinction.

A first-ever study conducted by researchers from the National University of Singapore (NUS), University of Adelaide and Princeton University on the full extent of amphibian, bird and mammal species rediscoveries globally has found that over the past 122 years, at least 351 species which are thought to have disappeared have been rediscovered. The rediscovery of these once-missing amphibians, birds, and mammals occur mostly in the tropics.

However, despite many rediscoveries, 92% of amphibians, 86% of birds and 86% of mammals are highly threatened, independent of how long they were missing or when they were rediscovered.

Under the current trends of widespread habitat loss, particularly in the tropics, most rediscovered species remain on the brink of extinction.

According to the lead researcher, Brett R. Scheffers, who is from the Department of Biological Sciences at NUS, most rediscovered species have small range size, which is the main driver in species extinction globally. "Rediscoveries, without aggressive conservation, likely represent the delayed extinction of doomed species and not the return of viable populations. In short, there is hope but we must step up rapid conservation efforts," he said.
“Endangered” and “Vulnerable” species; Non-threatened (blue line) includes “Near Threatened” and “Least Concern” species; Data Deficient (black dotted line) includes “Data Deficient” species, and Total (black solid line) includes Threatened, Non-threatened, and Data Deficient species. Additionally, 3 “Extinct” and 1 “Extinct in the Wild” amphibian species are included in threatened accumulation curves as individuals of each species were recently rediscovered in the wild. Top photograph: the Critically Endangered, Atelopus seminiferus, rediscovered in Peru in 2001; middle photograph: the Endangered, Gallicolumba hoedtii, rediscovered in Indonesia in 2008; and bottom photograph: the Critically Endangered, Prolemur simus, rediscovered in Madagascar in 1986. Photo credits: A. seminiferus courtesy of Jan Post, G. hoedtii courtesy of Philippe Verbelen. and P. simus courtesy of N. Rowe/alltheworldsprimates.org.


To make matters worse, the average number of years a species went missing is 61 years. This long duration makes conservation planning for missing species very difficult, particularly in areas that are of high value to humans. For instance, the protected areas that have been put aside for a particular species that has not been seen for numerous years could have be converted for agricultural use.

Findings from the study, which was published in PLoS One in July, are indicative of the limited knowledge of biological diversity in the poorly known tropics. Scheffers elaborated, "We still have much to discover and these results indicate that it may not be too late for many species that have gone unseen for many years."

"We support and encourage more biodiversity surveys in the poorly known tropics. This is particularly important as many museums are experiencing shortened budgets or event budget cuts," Scheffers added

Gopher Snake Found


Howdy Herpers,

50,000 comedians out of work, and Dave checks in with this:

I don’t know what’s the big deal, I saw that gopher hiding under the bush right away.

Dave

Where is the Gopher Snake? Roger Repp

I warned you Herpers!

Now we're getting plumb dog mean.

My wife, who loves me beyond all measure, sent me this image of a gophersnake that has been terrorizing the neighborhood of late. When I could not find "Waldo,"

in this image, she informed me that she was better than me at finding snakes.

This remark caused me to howl with laughter, snickers, snorts, and guffaws--accompanied by knee slaps and fits of wheezing and coughing.

As my wife felt that fits of laughter, snickers, snorts, guffaws, knee slapping and wheezing were unbecoming to husbands, she was inspired to further heights (depths?) of denigration of the poor husbands'character.

This haranguing was all based on a misunderstanding. SHE thought her husband was laughing out of arrogance toward her--based on the very thought that SHE was better than HE at finding snakes.

The poor woman does not yet understand that EVERYBODY is better at finding snakes than HE. THAT is why HE was laughing.

Enough with the levity.

Somewhere in the framework of this image is the head of a Gophersnake looking straight at you.


Find it, and you stand on the shoulders of giants. You may be as good as my wife at finding snakes.

Drag out the magic markers guys! But be sure to wait until you find the snake before you pull the cap off. No sense in letting the thing dry out from exposure...........

Best to all, roger

Tuesday, August 16, 2011

Snakes kill three farmers in Adamawa, bite 13 others

Next is reporting the following story on snakebites in Nigeria
August 12, 2011 07:57AM

Three farmers have died as a result of snakebite in Shuwa village in Madagali local government area of Adamawa, the News Agency of Nigeria (NAN) reports.

Thirteen other persons have also been hospitalised and treated for snakebites at the Christian Health Centre, Shuwa, in the last two weeks, according to residents.

NAN learnt that large numbers of poisonous snakes are on the loose in Kwajiti, Dzuyal, Paalam and Shuwa villages due to the mountainous nature of the environment.

The growing density of snakes has been exposing communities to incessant attacks, especially during the rainy season when the snakes move about in the open.

At least 35 persons were killed and 143 others treated of snakebites during the last cropping season in the area.

Most of the victims, including women and children, were attacked while working in the farms or while at home.

Some villagers, who spoke with NAN in Shuwa, urged the National Emergency Management Agency (NEMA) to provide snake repellents and anti-snake injections to facilitate the quick treatment of victims.

Suleiman Duhu, the sole administrator of Shuwa Development Area, said the authority had expended more than ₦1.4 million to procure anti-snake injections for the treatment of patients in the last one year.

"The rate of snakebites is alarming and beyond our control. We are sponsoring the patients for treatment at the Christian Health Centre, Shuwa.

"We are calling for assistance from NEMA and other health related bodies to control the disaster," Mr Duhu said.

He also accused the Adamawa State Ministry of Health of neglect in spite of formal complaints lodged before it on the development.

"The ministry had promised to provide hand gloves, rain boot, snake repellents and other preventive kits, but it is yet to redeem its pledge.

"We are calling on the NEMA and the state government to come to our rescue and control the spate of destruction of lives by the snakes," he added.

A farmer, Gambo Turai, told NAN that the snakes were making life unbearable for the residents.

"We are living in perpetual fear of working in the farm or even staying at home because you do not know when the snakes will strike.

"Many people have lost their lives to the snakes," Mr Turai said and called for urgent measures to control the situation.

Monday, August 15, 2011

Lake Erie Water Snake Removed from Endangered List

Nerodia sipedon insularum. Photo Credit 
Kristin Stanford
By Sabrina Eaton, The Plain Dealer 

WASHINGTON, D.C. - A non-poisonous gray snake that lives exclusively on Lake Erie's limestone islands has grown sufficiently in population to be removed from the nation's endangered species list.

Conservationists attribute the Lake Erie watersnake's dramatic recovery to a decade long public relations campaign and swelling numbers of an invasive fish from Eurasia - the round goby - which the snakes love to eat.

On Monday, Interior Secretary Ken Salazar announced the snake has joined the bald eagle, peregrine falcon and the American alligator in no longer being endangered. It is the 23rd endangered species to be delisted due to recovery.

"Our lake faces many challenges, but the recovery of the Lake Erie watersnake is living proof of what we can accomplish by working together," said Toledo Democratic Rep. Marcy Kaptur.

Ohio State University snake specialist Kristin Stanford, who leads a yearly drive to count Lake Erie watersnakes, says there are now between 12,000 and 15,000 of them, a tenfold increase since they made the list in 1999.

Although the 1 1/2- to 3 1/2-foot-long snakes are being removed from the federal list, they will continue to be protected in Ohio. Purposely killing one could still result in a fine of up to $1,000, says Stanford. Population levels will be monitored for at least five more years to ensure the species remains stable.

“As with most conservation success stories, the comeback of the Lake Erie watersnake is the result of different groups of people working toward a common goal," said U.S. Fish and Wildlife Service Director Dan Ashe.

Stanford, who calls herself the "Island Snake Lady" and whose snake counting work has been featured on the Discovery Channel show "Dirty Jobs," says the snakes were so ubiquitous when European explorers first arrived in Ohio that the Lake Erie Islands were initially named "Islands of Serpents."

Their numbers declined between the 1950s and 1980s, as the islands became a popular vacation destination and settlers destroyed their habitat and killed them in the mistaken belief they were venomous.

"If you pick them up and try to mess with them, they bite and poop and squirm and do what's necessary to make sure you leave them alone," says Stanford. "They prefer to be left alone."

According to the U.S. Fish and Wildlife Service, Lake Erie watersnakes are closely related to northern watersnakes, but lack the other species' prominent bands. The all-gray snakes were better able to survive by camouflaging themselves on the islands' limestone, helping them to avoid consumption by birds, foxes and raccoons.

Stanford and others began an informational campaign to publicize the snakes' history in the region, and the fact that no snakes around Lake Erie are poisonous. She said Ohio's only poisonous snakes - copperheads, massasauga rattlesnakes and timber rattlesnakes - live farther south.

The arrival of round gobies in Lake Erie - a bottom dwelling fish that came from the Black and Caspian seas via ballast water from ships - crowded out native fish like madtom, stonecat, and longperch, but helped Lake Erie watersnakes rebound.

More than 90 percent of their diet is round gobies, and the snakes' size, and reproductive rates have exploded since the invasive species arrived, says Stanford.

"You hear a lot of negative things about invasive species, but a lot of times you don't hear about the positive impact," says Stanford. "With the watersnake, it was a positive impact."

Saturday, August 13, 2011

Wheres Waldo Quiz: The Answers


Howdy Herpers,
 
Before launching into the answers to last week's "Where's Waldo" quiz, I wanted to add this image of a DOR Arizona Black Rattlesnake that turned up in the Galiuro Mountains on 2 July of 2011. This is a large adult male, that seems to be carrying the neonate pattern for cerberus. I've sent this off to the local cerberus Jedis, who think that the snake might have faded from black to the colors that you see now. The debate ended when it was suggested that we kill a few black cerberus and see what happens. Personally,  I really don't need to know.
 

Getting back to Where's Waldo:

Image 2: Ok hotshots, you made it through the first image. Way to shine! The head and a bit of flank of an Arizona Black Rattlesnake is visible in this image.
Image 2, answer. Since Melissa took the time to circle Waldo, we use her image. I've also shown a couple more angles of this snake. It was also found on 2 July, same date and locality of the dead cerberus above.







Image 3: Wow! You guys are GOOD. Feast your eyes on this Western Diamondback rattler amongst some hackberry, if you can! Roughly 80% of the snake is visible in this one.
Image 3 answer: See Melissa's circle. The second image shows the snake, CRAT # 121 "Tracy" in insitu. I had just poured some water over top of her, and she can be seen drinking lustily. This image was taken on 12 June 2011.







Image 4: And last, but not least, the same diamondback is now under catclaw--ouchie oochie. About 60% visible.
Image 4: Melissa's circle, and more of a close up image. The snake is Tracy once again, as she appeared on 9 July 2011




Ok, these were all too easy. NEXT TIME, we'll play just a little bit rougher.

And how!

Best to all, roger