Tuesday, April 30, 2013

Ground Skink


Ground Skink
Scincella lateralis


Although this picture is a little blurry, you can tell that this is a skink. This ground skink was a smooth, blackish-brown lizard with a white belly. This “elfish lizard" was found running in snakelike movements across the hill country horizon in Kerrville, TX in the middle of February 2013. It was a relatively cool day with constant cloud cover overhead. This skink mostly stayed still with its eyes closed the entire time it was being held. According to the Peterson Field Guide of Reptiles and Amphibians: Eastern/Central North America by Roger Conant and Joseph T. Collins, this species of skink can grow to be 3-5.5 in (7.5-14.6 cm) in length. This reptile was released under a fallen tree trunk close to where it was found running.

Flathead Snake


Flathead Snake
Tantilla gracilis

This worm-like snake was found underneath a medium sized flat rock in moist dirt in Early March 2013 in Kerrville, TX. This snake has been classified as a Blackhead snake but without a black head. This snake, since I would not touch it, looked like it had shiny brownish-gray smooth scales. According to the Peterson Field Guide of Reptiles and Amphibians: Eastern/Central North America by Roger Conant and Joseph T. Collins, this snake has been known to grow between 7-8 in (18-20.3 cm) in length. I noticed its belly was a light pink as it slithered through my friend’s hands. The snake was released at the edge of the rock it was originally found from after ten minutes of observation and classification.

Rio Grande Leopard Frog



Rio Grande Leopard Frog/Tadpole
Rana berlandieri

This frog was found in a pool in Quinlan Creek, a tributary of the Guadalupe River in Kerrville, TX in the late February 2013. According to the Peterson Field Guide of Reptiles and Amphibians: Eastern/Central North America by Roger Conant and Joseph T. Collins, this species can grow to be 2.25-4 in (5.7-10 cm) in length. The tadpole, found in relatively the same area, is also of the same species. It is believed that this tadpole was an offspring from last spring for it was too big to be hatched lately, for the cold weather and drought that was experienced in this area, has been known to stall this species of frog from mating. Both amphibians were put back into the water where they were found five minutes or less after capture.

Texas Spiny Lizard


Texas Spiny Lizard
Sceloporus olivaceus

This Lizard was found scurrying from a patch of prickly pear cactus to underneath a fallen tree trunk in a relatively untouched hill country habitat in Kerrville, TX in early February of this year (2013). My brave professor blindly stuck his hand underneath this tree trunk to carefully pull this species out to show it to our class. This "rusty" lizard was a characterized as a male for it had the distinguishing narrow light blue areas on the sides of its belly. This species can grow to 7.5-11 in (19-27.9 cm) in length. After classifying this animal from the Peterson Field Guide of Reptiles and Amphibians: Eastern/Central North America by Roger Conant and Joseph T. Collins, we let him go underneath the tree trunk my professor originally pulled him from.

Herps in the news: Frogs, Foam and Fuel


Are Anurans the answer to the energy crisis?
Not exactly, but according to researchers at University of Cincinnati they've inspired a solution. Motivated by the nesting foam produced by the Tungara Frog, Engystomops pustulosus, scientists have developed a foam capable of abstracting solar energy and capturing carbon dioxide from exhaust systems. The artificial, photosynthetic foam requires no soil and comprises of plant material, bacteria, frog and fungal enzymes. The inexpensive foam shows huge potential considering billions are spent globally to find an answer to dwindling fossil fuels. Economical and efficient, this could potentially be the breakthrough that saves the future of society.


http://www.greenbang.com/frog-foam-could-enable-carbon-capture-easier-biofuels_13875.html

Natural History: Ground Skink (Scincella lateralis)

Ground skink caught at Donnelley Wildlife Management Area
The ground skink (Scincella lateralis) is a small, extremely quick and agile member of the skink family (Family Scincidae).  I caught a ground skink in some leaf litter along side a shallow swampy area at Donnelley Wildlife Management Area with some difficulty.  I wasn't sure if I had caught it or not and it took me several attempts to grab it- a testament to just how elusive they are.  This skink is very adept at blending in with the leaf liter, sticks, etc. and evading potential predators.  I only saw the one I caught because it dashed off and I caught sight of its movement.  After its hard fought escape attempt it remained relatively calm as it caught its breath (like other reptiles, they cannot breath while they are running away).

The ground skink is also known as the "brown-backed skink" or the "brown bark skink".  They have long tails and may look like a tiny snake moving through leafs and debris on the ground.  They normally do not climb, which surprised me.  When I put the individual pictured above into the plastic container I was a little surprised that it was not able to climb out.  However, the ground skink "may enter shallow water in an attempt to escape".

Their coloration is variable but is usually "golden brown to blackish brown...with a dark dorsolateral stripe" according the the field guide.  Their stomachs are usually a lighter color.  Another interesting feature of the ground skink is that they have a special adaptation which allows them to see when they close their eyes.  A see-through lower eyelid could be very useful to protect their eyes from debris on the ground or water.  Also, the ground skink is known to undergo tail autotomy when threatened.  Their diet consists of small insects and spiders.

The ground skink mates between January and August and lays up to 5 clutches of 1-7 eggs during the spring and summer months, which take about 1-2 months to hatch.  They do not have any parental care as females abandon their eggs after deposition.  The young take about a year to mature.

This species is one of my favorites because of its unique coloration that has a distinct golden glimmer in the sunshine.  If only they were a little less elusive and a little easier to catch!


Works Cited:

Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles & Amphibians : Eastern and Central North America. Boston: Houghton Mifflin, 1998. Print.

Shapiro, Leo. "Scincella Lateralis." Encyclopedia of Life. N.p., n.d. Web. 30 Apr. 2013.









Review: Do frog-eating bats perceptually bind the complex components of frog calls?

"DO MY TONSILS LOOK SWOLLEN?"

Everyone's experienced a bad roommate, even the Túngara Frog, Engystomops pustulosus. Inhabiting Mexico and South America, these terrestrial frogs prefer wet habitats including tropical forests, low flooded marshland, and caves. During mating season males find shallow pools and call to females. Their mating call consists of one ~350 ms "whine" followed by a series of ~0.40-0.80 ms "chucks." While the "whine" alone suffices in attracting females, the "chucks" that follow make the call more attractive due to the frog's perceptual coupling of the sounds. While males call, sometimes unwanted, acoustic predators e.g. frog-eating-bats are attracted putting the caller at risk. Since frogs group the sounds of mating calls,  is there convergent evolution between calling frogs and bats that prey upon them?
Figure 1. Variation of calls used.
Dashed line separates calls
played simultaneously.
C = Chuck. W = Whine.

Researchers collected 10 bats from Panama for the experiment. Using 3 separate speakers, 300 different call variations from 50 Túngara frogs were played to decipher which calls bats would attract bats. A variation of single "whine" and "chucks" were tested in addition to complex calls consisting of both. In addition to separating the calls, scientists reversed the natural order of the calls and verify which portion of the complex mating call was more effective in attracting mates and predators. 

Figure 2. Mean bat responses to frog calls.
Astericks represent significantly different data.
Results conclude bats prefer "whines" significantly more than "chucks," but "chucks" alone suffice in attracting bats. In contrast, female frogs will not respond to "chucks" alone suggesting that bats are more flexible when processing mating calls than frogs. 

The experimental design was well structured, organized and executed. The only issue is the calls were too clean. In the natural habitat a cacophony of mating calls can be heard and may influence bat's frog call selection in a different way. This experiment aimed at isolating individual calls, but not a realistic approach as no environment would actually mimic this design. 

I read this article because I wanted to learn more about acoustic calling in frogs. In this case, while males are the active competitor for mating, they're also protecting females from acoustic predators. I wonder why females aren't attracted to single "chucks," but prefer calls that include them following a "whine." The entire process of male selection is a fascinating topic and by researching how other animals respond to their calls we can gain better understanding of anuran behavior. 





















Jones, Patricia L.. Do frog-eating bats perceptually bind the complex components of frog calls?  J OF COMPAR PHYSIO A-NEURO SENS NEURAL AND BEHAV PHYSIOVol. 199 No. 4. 2013 p. 279 - 283.

Herps in Society

Snakes in Society

Being in this course really has opened my eyes to how easy it is for people to kill a snake in their backyard just because it's a snake. I even remember my Grandfather telling me as a young girl "A good snake is a dead snake."

Why is it people freak out over snakes? Doing a little internet research I came across a countdown of the top ten phobias from 2011 and slithering snakes was number 1. Even Beat out spiders, heights and being in the dark. I thought it was interesting this site thinks that being afraid of snakes is an evolutionary trait that we have carried since the beginning of time (Bryner, J. 2011). Generally, being able to spot a snake increases one's chance of survival. Therefore, our fear of snakes is really an evolved survival trait. This makes sense to me because well, if you know what can kill you, you will steer clear of it to live. That doesn't mean our society should be this afraid of snakes or kill one if it's in your way of a hike. I blame this in part to movies that show snakes as venomous creatures that will always kill you if you don't kill it first. This probably enhanced the snake terror among society. After all, terror sells.

The Anaconda's movies always freaked me out as a child. I mean, just look how horrifying the movie poster was. Doesn't help society cope with snakes.


Then there was Indiana Jones and his famous "I hate snakes" line. Or, "Snakes? Why did it have to be snakes?" It's a line easily quoted and imprinted in one's mind forever.

Worse is the use of venomous snakes to assassinate someone. This has been used in a lot of movies and T.V. shows. Take Snakes on a Plane for instance.


If you weren't scared of snakes and planes before, you are now.

It doesn't help people to get over their innate fear of snakes by pranking them like in this video:
http://www.youtube.com/watch?v=OqHtgNajFxs

Sure it's funny for our enjoyment but it doesn't help people get over their fear of snakes.What does? I've seen people get over their fear of snakes by seeing celebrities interact with them. Like, back when Britney Spears was in her prime. This actually taught a few of us girls it's ok to touch non venomous snakes because well, they're non venomous and beautiful creatures. And in Britney's case, a nice LIVING accessory. No need to kill these beautiful creatures for their patterned skins.


Notice she's holding the constrictor at angle where it can't wrap around her neck. Above all, one needs to be careful when handling any snake ever.

And who could forget our favorite Aussie Steve Irwin? He was amazing at showing people around the world it's ok to be afraid of snakes and would show us which ones to not be afraid of. However, he always had to add a disclaimer to not pick up the poisonous snakes and play with them like he did. Advice well taken Mr. Irwin.


So what it all comes down to is simply being educated about these creatures; which was the life goal of Steve Irwin. We spent a good bit of this semester learning how to identify our local venomous snakes and its mimics as well as the harmless snakes. Now I can go home and convince my family over the summer that not all good snakes have to be dead ones in their minds. Yes, there are some to steer clear of but for the most part people do not need to be afraid of them. Hollywood likes to make snakes the bad guys but they're really good guys, for the most part. Just keep an eye out for them especially since it's warming up!

Work Cited:
Bryner, J. What Really Scares People: Top 10 Phobias | Fear of Snakes, Fear of Heights, Fear of Flying | LiveScience . Science News – Science Articles and Current Events | LiveScience. Retrieved April 29, 2013, from http://www.livescience.com/13434-phobias-fears-acrophobia-heights-agoraphobia-arachnophobia.html

Therapeutic potential of snake venom in cancer therapy: current
perspectives

Asian Pacific Journal of Tropical Biomedicine

By: Vivek Kumar Vyas, Keyur Brahmbhatt, Hardik Bhatt, Utsav Parmar


               There have been many documented studies suggesting the anti-cancer properties of snake venom.  Specifically, some proteins and/or peptides and enzymes from snake venom have been discovered to affect the proliferation of cancerous cells by binding to their membranes.  Snake venoms contain an assortment of these proteins, peptides, enzymes, as well as organic and inorganic compound.  The evidence behind the therapeutic potential of snake venom in cancer therapy are the findings of the studies mentioned in this article.  Many studies found complete remission of tumor cells after they had been treated with molecules made from the snake venom.  The various ways in which snake venom inhibits cell proliferation and promotes cell death are through the induction of apoptosis of cancerous cells, increasing the calcium influx, inducing cytochrome C release, and by decreasing or increasing the expression of proteins that control the cell cycle.

url.jpg


        This article adds to our understanding of snakes by better understanding the components of snake venom and their medical implications.  This article is specifically important due to its significant implications.  Cancer is a very deadly disease which impacts many people's lives.  It is caused by uncontrolled cell growth.  If snake venom is the key to slowing the disease, then it could be very beneficial.

Link:  http://www.sciencedirect.com.nuncio.cofc.edu/science/article/pii/S2221169113600428?np=y


Article Review: Rana ridibunda skin secretions accelerate wound healing





Article Review: Topical effects of frog "Rana ridibunda" skin secretions on wound healing and the reduction of wound microbial load


In traditional medical applications frog skin has been used as wound dressing for its effectiveness in speeding healing and its ability to reduce inflammation with its secretions. This article represents an investigation of these properties as it examines the effectiveness of frog skin secretion when applied to wounds on mice. The application of raw extractions (RE) of the secretions is compared with extractions of a different membrane size cutoff (U10E) as well as a control and a group with a different ointment (o). The wound closure and microbiology are observed and compared among these groups over a period of 6 days. The numbers of inflammatory and fibroblast cells and the amount of collagen fibers were some of the histological parameters observed and compared among the different test groups. The results show that the group with the membrane size controlled cutoff demonstrated the greatest degree of wound healing. The result tables for both wound closure and wound microbiology are shown below.



















The potential value of this is that it may eventually lead to the production of new materials, drugs, treatments, or perhaps just better understanding of the mechanisms of growth and repair systems of biological structures such as skin or tissues.

This article was interesting to me because it focused on the effect of skin secretions on wound healing, tying in directly to one of my current courses.  This semester in a physics course I learned about nano-scale self-assembly liquid crystal (LC) films from defibrillated chitosan nanofibers and how this biomemetic process may open up possibilities for research in accelerated wound healing (biological tissues are known to self-assemble in a similar fashion and principal proteins such as collagen, chitin, or keratin are primary constituents of soft tissue).

I was interested in the fact that there was significant correlation between wound healing and the increased amount of fibroblast cells (and the sequential higher amount of collagen).  I am curious as to which biomediated mechanism determines the structure and how it functions in wound healing, as well as ways this information may be valuable for a similar experiment reproduced with biomemetic materials.

Mohammad Mashreghi, Mahere Rezazade Bazaz, Nasser Mahdavi Shahri, Ahmad Asoodeh, Mansour Mashreghi, Morteza Behnam Rassouli, Shiva Golmohammadzadeh, 
Topical effects of frog “Rana ridibunda” skin secretions on wound healing and reduction of wound microbial load, 
Journal of Ethnopharmacology, Volume 145, Issue 3, 13 February 2013, 
Pages 793-797, ISSN 0378-8741, 10.1016/j.jep.2012.12.016.
(http://www.sciencedirect.com/science/article/pii/S0378874112008501)




Herps in the News

'Flipperbot' Crawls Like a Turtle to Save Them
Eric Niiler


A team of engineers from Georgia Tech and Northwestern University created a “flipper bot.” It’s an artificial sea turtle designed to study how a baby sea turtles move across the beach after hatching. They plan to use this to better study the physics of sea turtle locomotion and to protect them and their beaches. Many beaches undergo nourishment programs where they replace the sand lost from erosion. And if you get the wrong sand it could slow down how fast the sea turtles can get to sea. This is very important because there is a high predation rate at that short time period.
In their studies they noticed that not all sea turtles are good at running across the beach. Some were but others seemed to dig themselves in a hole trying to get across. The key seemed to be how they bent their wrists, but they had no evidence. So they made “flipper bot” to test the bends of their wrist and locomotion across sand. But since sand has some moisture problems, they used poppy seeds instead which has similar characteristics as sand but without the problem. “Flipper bot” has allowed them to study the locomotion of baby sea turtles repeatedly over long periods of time.


Back From the Dead?

Brian Howard and Christine Dell'Amore

On a side not I came across an interesting article that is a bit older, that came out last month. They are trying to resurrect the gastric-brooding frog. These frogs have been extinct since the mid-1980s due to habitat degradation, pollution, and disease. What is so unique about these frogs is that the female swallows her own fertilized eggs. Her stomach then stops producing acid and becomes a make-shift womb. But scientists are now trying to resurrect this extinct species through cloning. They had a few preserved specimens in Australian museums, and with that they managed to make embryos but have not been able to get any further. They believe this is due to how they are handling the eggs but work is still being done.

Article Links



Monday, April 29, 2013

The Green Anole


                                                    Anolis carolinensis


On a recent Herpetology Class field trip to Francis Marion State Park, I discovered a cute little anole.  It was most likely a female (less profound dewlap) and I would guess that it is approximately six inches,(the normal range is 5-8 inches). This anole, of the species Anolis carolinensis was an adult crawling on the ground under a large log. It is rare for an Anole to be seen walking on the ground as they are usually climbing. The habitat consisted mostly of tall trees and darker colored foliage with dead leaves, branches and tree trunks scattered along the ground in your typical forest environment. It was a dark greenish/brown color that I have rarely seen on Anoles in South Carolina and had a slight yet distinct pattern on its back in a darker brown or black color. All the other Anoles I have seen have been bright green and without a pattern on their back. However, most of the Anoles I have seen have been in a city setting and not in a forest environment. It therefore stands to reason that it would serve populations that live in a forest to evolve in a darker color to blend in with the foliage as opposed to the populations who live in the city, which would evolve to exhibit brighter colors found on bushes and vines. Anolis carolinensis is the only species of Anole found in South Carolina. It is commonly referred to as the Green Anole and the coloration can range from bright green to dark brown. These Anoles have a pink throat fan called a dewlap that is used for signaling.  The dewlap is much larger and much more easily distinguished in males. The color of the dewlap, often a deep pink is best seen as the fan expands and the scales along the dewlap expand to reveal the bright color. They also have small toe pads that assist them in climbing, everything from fences to vines to bushes to tall trees. They feed on small insects that they often swallow whole.
 Anoles are of the family Polychridae and only the species Anolis Carolinensis is native to the United States. There are currently six other species in the United States, now found in Florida, that are originally West Indian species. This is a small percentage of the number of species found in the genus Anolis,  as there are currently documented over 250 species worldwide. Most species are found in the tropics and further south towards Bolivia and Paraguay, according to our guidebook, Reptiles and Amphibians of Eastern and Central North America.
I personally loved finding this Anole as they are one of my favorite herps! In fact, the Green Anole was even my nomination for class mascot! I loved finding an Anole that was such a brown color and so different from any I have seen in Charleston, or at home in Columbia. Overall, this field trip was one of my favorites and the Green Anole was my favorite find of the semester!

Article Review: Organic farming and amphibian conservation


The economic efficiency of conservation measures for amphibians in organic farming-- Results from bio-economic modeling (Schuler et al. 2012)

As humans start to realize how detrimental industrial farming is to the long term health of our own population and the environment, it has become more and more popular to support organic farming. Because of this, large scale organic farms have begun to pop up around the world, especially in the US and Europe. However, although a main goal of organic farming is to increase the sustainability of agriculture, it often costly for farmers to reach this goal and minimize negative effects on the environment.  It is essential for farmers to reach economic goals by keeping prices low enough to compete with non-organic farmers. It is also essential to do this without sacrificing the environmental goals of organic farming. 

It is important to acknowledge that organic farming is still a form of habitat loss and degradation, but negative effects on species could be minimized by researching farming techniques that are less detrimental to populations. The objective of this article is to present a model that can be applied to other organic farms to assess the cost-efficiency of crop production activities (CPA) for amphibian conservation. Crop production activities are detailed descriptions of how certain crops are produced from beginning to end (tillage-harvest). The authors performed a model-based analysis to assess the environmental and economic effects of different CPAs. For example, the study assessed the effects of various changes in timing and intensity of what they referred to as "work steps" (ploughing, mulching, mowing etc.). They also rearranged the spatial configuration of crops and the total coverage of that crop.

The authors altered these variables over a six year time span on a large scale organic farm in Northeastern Germany. After altering the variables, they measured the suitability of a crop production activity for minimizing the disturbance and injuries to amphibian populations. This variable they referred to as habitat quality. The amphibian populations they investigated were of three different species: common spadefoot toad (Pelobates fuscus), fire-bellied toad (Bombina bombina) and the European tree frog (Hyla arborea).

The table below is a little bit overwhelming, but the numbers for each data point represent the injury rate per work step (WR). This means that the higher the number, the more detrimental it was to the amphibian population. The different species are represented by letters. Overall, it appears as though the different species of amphibians respond similarly to the work steps. There are exceptions where adult tree frogs seem to be more sensitive to some work steps than other species and life stages ( mowing, combine harvesting etc.) As we might expect , ploughing had much more of a negative effect than any other work step.




The authors conducted several other experiments, including assessing the impact of buffer strips around amphibian breeding ponds, and assessing the impact of different crop types on habitat quality. In addition, the economic result of changing these variables was assessed in order to analyze trade-offs between economic and environmental goals. Although the aim  of the study was to reorganize the farm so that the habitat quality of amphibians would be increased, the main goal was still to maximize the total economic benefits in conjunction.

In conclusion, the authors found that some improvements in habitat quality for tree frogs could be satisfied  by small changes in the organization of the farm.  However, a large increase in habitat quality would probably result in significant economic losses to the farm. Also, their results suggested that an increase in buffers did not have a significant positive affect on amphibians unless a high level of habitat quality is aimed for. In other words, farmers should minimize habitat loss in other, more cost-effective ways than buffers if they wish to maximize both economic gain and habitat quality. For example, the authors found that a decrease in peas led to an increase in habitat quality and peas are also less profitable than many of the other crops.

Studies such as this will be important in the future as organic farming becomes the more preferred way of farming.  It has become apparent that we must find more sustainable, environmentally favorable ways to feed a growing population or else we will continue to decrease biodiversity at an alarming rate. By considering economic, social, and environmental aspects of farming, this goal may be reach effectively.

Schuler J, Sattler C, Helmecke A, Zander P, Uthes S, Bachinger J, Stein-Bachinger K. 2012. The economic efficiency of conservation measures for amphibians in organic farming-- Results from bio-economic modelling. Journal of Environmental Management. 114: 404-413



Ophisaurus ventralis natural history

Last Friday I received a call from my little brother Phillip. He was at an open house in St. Petersburg Florida and noticed a rather strange looking "snake" in the bushes in the front yard. When I answered the call he asked if I had ever seen a snake that has a head like a lizard and a crease running down its sides. This was very exciting to me as I knew it could only be one thing in the southeast: a glass lizard. I told him to take a picture and send it to me and to go ahead and catch it, but to do so near the head because the tail would likely autotomize if he grabbed it too far back. You can see that this one already lost part of its tail before the encounter.
These are the pictures of what he found:
photo.JPGphoto.JPGphoto.JPG



















 I have determined that this is an eastern glass lizard (Ophisaurus ventralis). This unique legless lizard has osteoderms that help make the skin more ridged. It is due to this hard outer shell that glass lizards have the dorsolateral grooves that can be seen in the family Anguidae. One can tell that this is a lizard and not a snake because it has ear holes as well as eyelids (snakes lack both of these)As Ophisaurus is the only genus that we have in the southeastern united states (and this specimen does not have any legs) 4 options were possible O. ventralis, O. mimicus, O. Compressus, and O. attenuatus. O. mimicus is not located that far south in Florida (and would more likely be confused with the slender glass lizard O. attenuatus). O. attenuatus (The slender glass lizard) can be ruled out because there are no lines below the dorsolateral groove, it is also thinner than the eastern glass lizard. Finally the Island glass lizard, Ophisaurus compressus can be ruled out because it has a thin distinct line running above the dorsolateral groove In addition all three of these other glass lizards tend to have a dark line runding down the mid-dorsum. As the area right behind the cloaca was not swollen I would assume that this individual was female.
Glass lizards are typically good burrowers and can spend some of their time underground making them sometimes difficult to find. I included the picture of where Phillip found the specimen (and yes it is in the picture it is just very difficult to see). They will eat insects, smaller reptiles, and bird eggs and span a majority of the southeastern united states.
I felt compelled to write about this find because it is likely one of the most mistaken reptiles. Although Phillip could tell there was something weird about this animal, the natural tendency is for people to assume that because it is legless, it must be a snake. I am really glad that Phillip has such a keen eye and was able to spot the lizard even though he was not actively searching for it.

Natural History: Pygmy Rattle Snake



The Carolina Pigmy Rattle Snake, scientific name Sistrurus miliarius miliarius, is an extremely well equipped and fascinating snake. Its range is from the southern most part of South Carolina to the southeastern part of North Carolina. It is one of three subspecies of the Pigmy Rattle Snake, Sistrurus miliarius. The subspecies are differentiated primarily due to pattern deviation and geographical location. Populations of Dusky Pigmy Rattlesnakes, Sistrurus miliarius barbouri, extent all the way through Florida, and Western Pigmy Rattle Snake populations, Sistrurus miliarius streckeri, extend all the way to eastern Texas.
These snakes are rather small rattlesnakes compared to the genus Crotalus, reaching only a record size of 31 inches. They further differ from their Crotalus brethren based on their head shape and head scale pattern. Crotalus has a wider and broader head composed of numerous small scales, while Sisturus has nine large-scale plates on the crown of their head. Pigmy Rattlesnakes generally have a light brown to greyish coloration with dark brown blotches going down their backs and flanks. The patterning on miliarius miliarius is very clear-cut and vivid and it is often witnessed to have a reddish tint to it. The other two subspecies have more of a dusky or less vivid patterning.
These snakes possess a tiny rattle constructed by keratinous shed skin. Most other rattlesnake species will always utilize their rattles to ward off predators, however Sistrurus only irregularly does. When threatened sometimes individuals will sound off their miniscule rattle, while other times they will remain motionless. Many herpetologists go as far as categorize Sistrurus miliarius in a group with a few other rattlesnakes known as the “rattleless rattlesnakes”. Nonetheless, when used the small rattle will produce a slight buzzing sound that can only be heard from several feet a way. This causes many herpetologists to speculate as to why Pigmy Rattlesnakes have such a small rattle or even a rattle at all. Some hypotheses suggest that the snake’s small size, leading to infrequent shedding, results in the trifling size of their rattle. However, based on their reluctant use of their rattles and other morphological shortcomings, it is more widely thought that Pigmy Rattle Snakes represent a basal group to all rattle snakes. Therefore, Sistrurus is a frequent character in studies analyzing the origin of rattlesnake rattles. When juveniles, the tips of their tails are equipped with a vibrant yellow coloration that is used to lure in prey. When older this coloration fades, but their rattle gets larger. Some herpetologists further hypothesize the driving force of the origin of snake rattles is actually a lure for prey. There are herpetological studies that provide evidence of visual similarities between the tip of a snake rattle and arthropods (a typical prey choice of lizards, frogs, and many small mammals).
These snakes have the ability to be successful in a wide variety of habitats. However they typically prefer longleaf pine habitats due to the large abundance of burrows constructed by Gofer Tortoises and small mammals. Juveniles thrive off of a diet of insects and small lizards, and adults add on small mammals and birds to their diet. Pigmy Rattlesnakes utilize a largely hemorrhagic venom to immobilize their prey. Hemorrhagic venom is a composition of toxins that, when injected, result in excessive internal and external bleeding.
This venom is very effective to immobilize their small prey, however, in relation to deterrence of predation, venom is rarely used. Pigmy Rattlesnakes are typically unaggressive and, as briefly stated above, rely on their camouflage as their first line of defense. Witnessed aggressive behavior (frequency of strikes) is directly correlated with the vulnerability of its posture. When coiled, the snake typically does not strike unless relentlessly pestered. Conversely, when uncoiled the hostility of this snake is significantly increased. However, despite being primarily unaggressive, the invisible nature of this snake leads to many accidental human encounters. Consequently, this snake is responsible for a large number of snakebites in the southeastern United States. However, despite the numerous human envenomations, the venom from this snake poses a very small threat of fatality to humans, but will cause extreme discomfort. 

Herps in the News: An inspirational story of a child's love for sea turtles

A Sea Turtle Named After a Boy with Terminal Cancer


Silas Edenfield, 4 saying goodbye to Silas the loggerhead sea turtle
 
On Saturday April 27th two loggerhead sea turtles (Caretta Caretta) named Silas and Chatham headed for the hills or the seas in this case. The Georgia Sea Turtle Center released the sea turtles on Tybee Island, Georgia. Both turtles at the time before release were being treated for cold-stunning, where turtles fall ill from instant exposure to cold water. However, how Silas got his name is a different story and an inspirational one to say the least.
            Silas the loggerhead sea turtle received his name from a four year cancer patient, Silas Edenfield. At just a young age his parents noticed that his belly was abnormally shaped leading to the diagnoses of liver cancer at just the age of three. During the past year Silas has been fighting for his life battling cancer by undergoing numerous treatments and surgeries. Silas fell in love with loggerhead sea turtles when he watched a popular kid’s show called “Go Diego Go” where they featured the turtle. Since then his mother and father reported watching the same episode “over a hundred times”. He has also accumulated several stuffed loggerhead turtles toys. Silas’s love for the sea creature never went unnoticed and eventually spread. When hearing about the news in the community the Georgia Turtle Center then honored the family by naming a loggerhead sea turtle after the cancer patient.

            At first it was thought that Silas Edenfield would not be able to make it out to where the turtle was being release because his conditions were slowly deteriorating. However, on Saturday morning due the enormous support from the community Silas was feeling well enough to make it to the beach and was even flown from Vidalia to Tybee on a private plane offered by a generous donor. During the release the rules are not to touch the sea turtles although in this special case Silas got to say goodbye to the loggerhead turtle that was named after him by touching the shell and seeing the turtle up close. The passion that Silas Edenfield shows for sea turtles at such a young age is extremely inspirational. He is a hero and a brave young man in many people's eyes.    



 

Sources:



 

Chelsea Taylor

College of Charleston

Sunday, April 28, 2013

Cultural Herps

In our society, the media influences the public's perception of different animals, either by associating them with the villains or as heroes for their owners. The most influential story about a herp comes from the biblical story of Adam and Eve. In the Garden of Eden, the serpent which symbolized temptation and disobedience, convinced Eve to eat from the tree of knowledge of good and evil. Since then snakes and reptiles have been seen as evil doers, conniving and dangerous. Various action and horror movies like anaconda and snakes on a plane utilize snakes as villains subsequently arts such as the snake path in the university of California designed by Alexis Smith and Lair of the Serpent by Elihu Vedder are famous pieces that promote the beauty of reptiles. In some cultures, due to the skin shedding ability of snakes they are seen are immortal and a symbol of male fertility.
Not all media pieces portray Herps badly, frogs and turtles are always depicted as intelligent, graceful with welcoming personalities. World wide personalities like kermit the frog, the geico gecko and the transcending teenage ninja turtles. Just as snakes have a tale, turtles are part of folk lore as using their wit to outsmart its competition the hare.Their trials include a race between the turtle and the hare, although the hare is faster but the turtle uses cunning genius to win the race, from this the tale "slow and steady wins the race".
In conclusion, snakes are general seen as bad but they only show these qualities when provoked, or their habitat under attack while frogs and turtles are considered easier to incorporated into our society.

Vincent Essien

Resources

http://www.mythencyclopedia.com/Sa-Sp/Serpents-and-Snakes.html#b

Article Review: Tail breakage frequency as an indicator of predation risk for the aquatic snake Natrix maura


Tail breakage frequency as an indicator of predation risk for the aquatic snake Natrix maura
Authors:  Xavier Santos, Mónica Feriche, Raúl León, Aikaterini Filippakopoulou, Marta Vidal-García, Gustavo A. Llorente, Juan M. Pleguezuelos

In this article, the viperine snake (Natrix maura) was studied.  N. maura is native to the Iberian Peninsula and can be found in a variety of aquatic habitats.  This species has a large number of natural predators including a variety of birds, some mammals, and other snakes.  The viperine snake is frequently found living in fish farms which protect the snakes from predation as the fish pools are covered with wire mesh.  Since the snake populations found in the fish farms are not exposed to predators like natural populations are, they offered the researchers an opportunity to study predation factors in this species.  

A common feature of this species is the ability to break off their tails as a way to get away from their many predators.  The researchers wanted to test their hypothesis that different N. maura populations would have intraspecific variation in terms of tail breakage.  The researchers recorded sex, size measurements, and tail breakage in three different natural populations and compared them all to a population found at a fish farm.  They found that the data did support their hypothesis.  They found that larger individuals had a higher frequency of tail breakage and that sex did not have any significance.  Most importantly, the results showed that the frequency of tail breakage was significantly lower in the fish farm population compared to the three natural populations.  In the fish farm population 5.1% displayed signs of tail breakage, where as in the three natural population 18.7% showed signs of tail breakage.  Since there were no differences found between the three natural populations, they concluded that tail breakage was a good way to measure predation risk for N. maura.

This article was well written, however I think the experiment needs to be replicated.  There were not as much data for the snakes found in the natural habitats, and the fact that the snakes found in the fish farm were preserved and studied later adds more room for error.  I think the researchers may need to back up their findings with more raw data.


Article:  

Santos X, Feriche M, Pleguezuelos J, et al. Tail breakage frequency as an indicator of predation risk for the aquatic snake Natrix maura. Amphibia-Reptilia [serial online]. August 2011;32(3):375-383. Available from: Academic Search Complete, Ipswich, MA. Accessed April 28, 2013.


Link: 
http://ehis.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=96946360-e246-429f-8d4a-4afdff6d5c26%40sessionmgr11&vid=2&hid=110