Saturday, September 3, 2011

Western Australia's New Gecko in the Genus Underwoodsaurus

More than 40 species of geckos in four families inhabit western Australia's Pilbara. Three species of carphodactylid geckos are known in the Pilbara by three species in two genera (Nephrurus and Underwoodsaurus).The Pilbara Nephrurus include two relatively common and widespread endemic subspecies; N. levis pilbarensis and N. wheeleri cinctus. Underwoodisaurus is much rarer, and known from relatively few specimens and scattered observational records An undescribed Underwoodisaurus was first collected in 1997, but lack of further specimens prevented a proper assessment of its taxonomic distinctiveness. Bought and Oliver (2011) now report on recent collections and photographic records which provided sufficient material for a comparison with U. milii, the other Pilbara Underwoodsaurus, and evidence to warrant its formal description as a new species. The describe Underwoodisaurus seorsus, a new species similar to U. milii, but differing in its plain dorsal and head patterns; sparsely scattered pale tubercles; more gracile build; longer snout, limbs and digits; smaller and more numerous fine scales on the dorsum, and the enlarged tubercles on the tail tending not to form transverse rows. Underwoodisaurus seorsus is known from few specimens and has only been encountered at mid elevations in the Hamersley Ranges, widely separated from the closest populations of U. milii in the northern Goldfields and Shark Bay in Western Australia. U. seorsus has only been collected from rocky areas, and U. milii are frequently associated with rocks. The distribution of U. seorsus and U. milii suggests that their common ancestor was once more widely distributed, but aridification and increasing temperatures eliminated populations in the Gascoyne region. The rocky gorges and moderately high elevations of the southern Pilbara ranges may have acted as a relatively moist and potentially cooler refugium, allowing an isolated population of Underwoodisaurus to persist at mid elevations. Given its rarity and small distribution it may be in need of protection.

Citation
Doughty P. and P. M. Oliver. 2011.A new species of Underwoodisaurus (Squamata: Gekkota: Carphodactylidae) from the Pilbara region of Western Australia. Zootaxa 3002: 20–30.

Retraction on Prebutton Stuff


Howdy Herpers,

Abraham Lincoln once said: "It is better to be silent and be thought a fool, than to open ones' mouth and remove all doubt."

On the other hand:

"What's the sense in being stoopid if you can't prove it?"

Mike Cardwell has convinced me that my little atrox did indeed shed their prebuttons.

Mike has given me permission to quote his words:

"Why do you think the tip of your neonatal sheds are wide open and oval in shape? Why isn't the end all shriveled like the rest of the exuvium - or like that of sheds from older snakes, for that matter? It's held open by the birth button inside! Turn one inside-out... or cut it open. I've attached a photo of two post-partum exuvia from C. mitchelli pyrrhus, with one turned inside-out. I know that scuts, cerastes, and helleri all shed the birth button and I'd bet a lot of money that all rattlesnakes do it the same way. (Be careful there, Mike. You're starting to sound like Roger Repp). I have other photos (somewhere) of back-lit birth buttons on neonates where you can see the first "permanent" button forming inside. The birth button comes off with the post-partum shed!"

Image 1: Mike's image of prebuttons of neonate speckled rattlesnake sheds:
Mike's effort inspired me to go back after my little atrox shed skins. Following his advice, I pulled the prebutton inside out, and took some photos. (The process of pulling the prebutton inside out could be likened to pulling the feces out of a fly's rectum. You sure know how to have fun Mike!)


Image 2 and 3: Ladies and gentlemen, I am proud to present the prebutton of Crotalus atrox.


Now that I understand what a prebutton is, I have a newfound lack of respect for it. Talk about much adieu over nothing? A mucous membrane dingleberry? Why..........there ain't enough there to make a jock strap for a flea............

Now, will somebody please go and wake up the clouds?

Best to all, "Wrong Again Roger"


Suizo Report -- Shattering the Pre-button Myth


Howdy Herpers,

In discussing the monsoons of 2011, when it comes to our beloved Suizo Study Plot, it could be worse. We could be in Texas! To my friends in Texas, let me say that on occasion, you guys are in my thoughts and prayers for rain. But it’s pretty hard to get past reserving my thoughts and prayers for our own area. It has not been all that great here, either. In fact, this just might be the worst monsoon we’ve ever seen. (And we’ve seen some bad ones……..)

Somewhere within the bowels of my computer, I’ve buried 10,000 lamentations about what an absolute wretched spring and summer 2011 has been. A depressing report of death, blight, dementia, jock itch and the reality of global warming was one shaky trigger-finger away from being shipped to the lot of you.

When presented with the opportunity to snuff Gollum in J.R.R. Tolkien’s “The Hobbit,” Bilbo Baggins decided to play nice. “Pity stayed his hand.” (It’s a pity he didn’t throttle the miserable little SOB when he had the chance. That would have saved us a lot of useless-­if not enjoyable reading, and several epic movies in the process.)

Yup! “Pity” stayed my hand from having the moxie to snivel to you all about how downright disappointing it is to hope for the best--and get the worst, of what the true herp geeks in Arizona want to experience. We wait all damn year in anticipation to see towering thunderheads bearing down on us in early July. We wish, hope and pray for the first inklings of cold air to shove massive sandstorms of cold, dry air into every bodily orifice­-exposed or otherwise. The frigid rush of air and bead-blasting effect of harsh desert turf rapidly on-the-move has to be experienced to be believed. In a good monsoon, the relief that comes from this blast is followed by bone-chilling and torrential downpours that make even crossing the street an adventure. And in a good monsoon, this all happens every day!

But, no! None of that this summer. The few chances of the entire scenario happening ended with the sandstorms. The rain that was supposed to follow didn’t occur. Time-after-time, it was just a dry-assed blow that was followed by flat, featureless, lethargic and apathetic clouds. An absolute dud! And now all we can do is wait and hope for the summer 2012………….

How can anything in nature survive such a summer? Well….some didn’t survive. Their sad story may be told someday. But the fact remains that some of the herps under our watch not only survived-­they thrived!

This is our text.

Image 1: Meet one of our two new female Crotalus atrox, CA133. She was found by John Slone on the evening of 6 August 2011. She was exactly what we were looking for in terms of receiving a transmitter. But the complication to that decision was that she was pregnant, which makes for a difficult surgery. We decided to keep her until she gave birth.
Image 2: And on 17 August, she gave us 6 beautiful babies, 4 males, and 2 females:
Image 3: Now we’re going to take the opportunity to zero in on the rattles (pre-buttons) of two of these snakes. Keep in mind that it will be six more days before these snakes shed their skins as you look at these pre-buttons. (Don’t be distracted by anything else on the image guys! Stay focused on the pre-buttons­I’m trying to teach you something here!)
Image 4: And now, let’s take a look at the full button on one of the neonates that has shed:

Take a moment to absorb what you’ve just seen, and we’ll move on.

Got it? Image 3 depicts the pre-button as just a nub, and although poorly photographed, image 4 shows that after the snake has shed, a “flange” of sorts emerges to join the nub. And now, are you ready for this?

The pre-button does not come off when the snake sheds its skin! It grows to become a full button.

Image 5: Let’s take a look inside the tail/rattle portion of one of the neonate atrox shed skins. Do you see any pre-button inside of it? Nope! That’s because the pre-button is still on the snake, in the form of the top nub on the full button.
Image 6: A side look at the tail/rattle portion of a neonate shed skin. 

I tell you these things because there is a lot of misinformation out there about what happens to the button before and after a neonate rattler sheds its skin the first time. While there may be species of rattlesnakes that do something different, Crotalus atrox does not shed off its pre-button! End of lesson, but not this report.

Image 7: As I’m sure none of you remember, mention was made of two new females entering our study. Well, the second female is not actually new. She is an old friend. Thanks to the miracle of PIT tags, we were able to identify the atrox below as female CA87. She was first captured in April of 2005 and, at the time, deemed much too small to receive a transmitter. She was at that point in time only 2.5 years old-­a little 250 gram sweetie of a snake. And though we’ve been all over her turf in the six plus years that followed, we did not see her again until 7 August 2011. My how she has grown! Her mass was 739 grams at capture­she has tripled her size! Once again, this snake was deemed pregnant, and we decided to play it safe, let her have her kids, and then do the surgery.
Image 8: On 15 August, our old friend dropped 12 beautiful children for us. The sex ratio was 5 males, 7 females. Yay for the girls! The N of 12 is 3 more than we have ever seen come from the atrox on our plot. We have twice had females give birth to 9. Most events have had less than six. Say hi to the babies everybody!
Image 9: By 24 August, the little ones had all shed. Now it was time to get those shed skins.

Yikes! Open carefully!

Image 10: They may be cute, but each and every one of these were little demons from the depths of hell in temperament. Biting worms, all of them! They were striking at anything that came close. As I transferred each one from their “nest” to a clean box, I did so at eye level. As I did so, several launched strikes at my face. How can something so tiny have such a big, fearsome mouth? Yehaw!
A side observation is in order. Prior to shedding, the little guys did not climb to the top of their nest box. Once they shed, they did so earnestly. I have noticed that in the wild, the neonates tend to go vertical.

I counted each one as I transferred them to their new quarters. At one point in the count, I jostled their nest box, and it crashed to the floor. But I thought I was on it quick enough. I continued on with the transfer.

“One-two-three…CRASH! "CRAP!" Four-five…………ten-eleven!

ELEVEN! HOLY $HIT! WHERE’S NUMBER 12?

I could visualize the topic of conversation that morning with my long-suffering wife Dianna. “Uh…….heh-heh, Sweetie? I think it might be a good practice to wear combat boots around the house for, oh, say….. the next year or so………..”

But I groped about on all fours, and found number 12 snuggled against the side of one of coolers on the floor. Whew! That was WAY close!

Image 11: This was the mess that stared me in the face when the shed-gathering was done:
Image 12: As each individual shed skin contains its own DNA, they have to be bagged separately. Thanks to the gentle, patient hands of Dianna Repp, the snarl depicted above eventually became:
And so now, they’re all bagged and tagged, and ready to hand off to the gel jockeys. Everybody is back out on the plot again. I had hoped to stage some photographs of the moms with their babies in the wild­-but that wasn’t going to happen. In their angst to gain their freedom, the babies morphed into whipsnakes, and scattered like dust in the wind. Trying to control that melee would have been several bites in the making.

With the next report, I will cover some of the birthing that occurred in the wild. But for now:

This here is Roger Repp, signing off from stinking hot Arizona, where the turtles are strong, the snakes are handsome, and the lizards are way above average.

And may the sun someday be more than a few inches from the top of our heads!

Friday, September 2, 2011

Salamanders, Rattlesnakes, & Tortoises - Conservation News


The Center for Biological Diversity Announces news for endangered herps. Each announcment is linked to a longer press release.

47,000 Acres Protected for California Tiger Salamander
In response to a Center for Biological Diversity lawsuit, the U.S. Fish and Wildlife Service this week designated 47,383 acres of federally protected "critical habitat" for the California tiger salamander's Sonoma County population. The move reverses a 2005 Bush decision to set aside no critical habitat; it protects many "vernal pools" that host the salamander during winter rains as well as increasingly rare grasslands and oak woodlands.

The Center earned protection for the Sonoma County tiger salamander in 2003. This yellow-spotted, black amphibian is threatened by development, pesticides, hybridization with nonnative salamanders, disease and predation.

Declining Rattlesnakes
Just days after one snake species, the Lake Erie water snake, was declared recovered thanks to the Endangered Species Act, a snake researcher and the Center for Biological Diversity petitioned to save another snake under the successful law. The eastern diamondback rattlesnake -- the largest rattlesnake in the world -- is native to the Southeast but dwindling fast due to habitat loss and human exploitation, especially through "rattlesnake roundups" -- grisly festivals that encourage the collection and slaughter of these imperiled snakes.

"The Endangered Species Act just saved the Lake Erie water snake -- it's the surest tool we have to save the diamondback rattlesnake too," said Collette Adkins Giese, the Center's attorney devoted to saving reptiles and amphibians.

Recovery Plan Weakens Desert Tortoise Protection
Instead of upgrading protections for the Mojave's desert tortoise, the species' new federal recovery plan makes matters worse for the ancient, threatened reptile. Until the new plan was released last Friday, the tortoise's recovery plan -- a document laying out steps and criteria for removing the species from the endangered list -- hadn't been updated since 1994. And now, while tortoise populations continue to crash, the revised plan fails to address some of the direst threats to the species, including livestock grazing, off-road vehicles, nonnative plants, climate change and energy development.

The Center for Biological Diversity has been working to save the desert tortoise since the '90s, when we filed our first appeals to stop harmful livestock grazing in tortoise habitat. So Center biologist Ileene Anderson has good authority to compare the old and new plans: "The new recovery plan only exacerbates the ongoing problem of desert tortoise recovery, which has been the failure to implement most of the science-based recommendations in the old plan. This plan simply doesn't cut it."

The Evolution of Communication: Tungara Frogs & Trachops Bats

Tungara Frog, Engyostomops pustulosus. JCM
A research team that included Hamilton E. Farris, PhD, Research Assistant Professor of Neuroscience and Otorhinolaryngology at LSU Health Sciences Center New Orleans, reveals that two entirely different species show similar perception of auditory cues that drive basic biological functions; that these perceptions may be universally shared among animals; and that such perception may also limit the evolution of communication signals.

The work is published in the August 5, 2011 issue of Science.

Using the labs at the Smithsonian Tropical Research Institute in Panama, the team tested whether psychophysical laws explain how female túngara frogs and frog-eating bats compare male frog calls and whether the rules for perception constrain how communication signals evolve.

Animals, including humans, continuously make decisions based on comparing external stimuli from the environment. However, the decisions are not based on the actual, but rather the perceived physical magnitude of the stimuli. A perceptual rule called Weber's Law proposes that stimuli are compared based on ratios, not absolute differences. For example, distinguishing between a 1-lb. object and a 2- lb. object is easier than comparing a 50-lb. object vs a 51-lb. object. The comparison does not depend on the absolute difference (1 lb. in each case), but the relative difference (100% vs. 2%).

The researchers tested whether Weber's law or alternative hypotheses explain túngara frog mate choice. Male túngara frogs produce a vowel-like "whine," followed by 0-7 consonant-like "chucks." They placed wild-caught females in a sound chamber and alternately broadcast two call types with varying numbers of chucks from two speakers on opposite sides of the chamber. Choice was quantified as walking to within 10 cm of either speaker.

"By giving females a choice between calls with different numbers of chucks, we found that the female frogs prefer calls with the most chucks, but based on the ratio of the number of chucks.," notes LSUHSC's Dr. Farris. "This means that as males elaborate their signals by adding more chucks, their relative attractiveness decreases due to the perceptual constraint on the part of females."

To more fully understand how females' perception influences the evolution of the males' calls, the research team then tested fringe-lipped bats, a natural predator of túngara frogs who select their prey based on the calls of the male frogs. Using this rare case in which two very different species, amphibian and mammal, have evolved the same behavioral approach to the same communication signal, the research team asked whether hunting bats choose their prey based on chuck number ratio as well. Testing bats in a behavioral test similar to that used with female frogs, the team showed that bats compared calls using chuck number ratio as well.

"It is astounding that two disparate animals use the same perceptual scale, suggesting a generality in how animals compare stimuli," says Dr. Farris.

As males increase chucks, so do their neighbors. With a fixed difference of one chuck between neighbors, both the risks and benefits of adding chucks decrease with increasing elaboration. Adding one chuck to many chucks adds less risk than adding one chuck to few chucks. Adding multiple chucks to outcompete neighbors will not succeed because males maintain a fixed difference.

"Natural selection and bat predation are not limiting male call evolution, This supports our conclusion that it is the females' cognition that is limiting the evolution of chuck number," says Dr Farris. "The results are significant because we show that certain types of perception may be universal. Furthermore, with respect to the evolution of communication signals, we propose that by limiting signal elaboration, ratio-based coding could favor the evolution of signal innovation. That is, Weber's law would favor the evolution of a signal along a completely different perceptual axis."

The research team consisted of Dr. Karin Akre, Ms. Amanda Lea and Dr. Michael Ryan of the University of Texas-Austin, as well as Dr. Rachel Page of the Smithsonian Tropical Research Institute, Panama. The research is supported by grants from the National Institutes of Health, the National Science Foundation, and the American Association of University

Citation
Karin L. Akre, Hamilton E. Farris, Amanda M. Lea, Rachel A. Page, Michael J. Ryan. Signal Perception in Frogs and Bats and the Evolution of Mating Signals. Science, 2011; 333 (6043): 751-752 DOI: 10.1126/science.1205623

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