Showing posts with label herpetology. Show all posts
Showing posts with label herpetology. Show all posts

Caught in the Act - Some News Coverage

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Photo by Ricardo B. Brazziell. © Austin American-Statesman 
A week or so ago, students working with Dr. Ben Pierce, including myself, conducted a monthly visual encounter survey at the Twin Springs Preserve in Williamson County, TX. We do these surveys at two sites every month, and we look for a local species near and dear to our hearts: the Georgetown salamander (Eurycea naufragia).

The survey I just mentioned was special in that we had a reporter and photographer from the Austin American-Statesman newspaper take some photos and write an article for this week's paper. I was flattered to be included in the article - as it was primarily focused on opening up this preserve to county-trained, permit-carrying individuals.

Here is the article: 'Georgetown-area preserve open for visitors -- but only after some training'. I'm the guy in the stylish blue Animal Behavior Society shirt I designed.

Also - take note that in the right-hand sidebar on this blog, I have some links for my most current CV and press such as this article.

Eurycea naufragia. Photo by Alex Hall.

Boy or Girl?: A Climate-Fated Adventure In Lizards

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Niveoscincus ocellatus (Photo credit)

Ever caught yourself wondering what it might be like if you could know the sex of your future children? Several methods allow for this to be determined with modest accuracy in the late stages of a human pregnancy, but what about early pregnancy? Before pregnancy? In other animals?

Sometimes the answers to these questions can be predicted based on the context in which they are asked. For example, I came across this article this article a few months ago, and would like to share its findings (full paper here; additional source). Essentially, the researchers found that climate, combined with genetics, was a main determinant of what sex-determining system emerged in a species of lizard.

But isn't sex in vertebrates determined by chromosomes? Not always. For instance, in many (not all) reptiles, sex is influenced by environmental factors, often temperature (i.e., temperature-dependent sex determination, or TSD). But how would a knowledge of TSD help you predict the sex your offspring? Well consider the example offered by our study in question.

In these experiments, an international cohort of herpetologists collected and observed female Spotted Skinks, Niveoscincus ocellatus from two types of habitats in Tasmania: highland and lowland. The habitats differ in altitude and therefore atmospheric oxygen, UV irradiation, moisture, and temperature, among others. Female N. ocellatus from the lowland habitat, when raised in a lab setting, varied in the ratios of male/female lizards based on the amount of sunlight they were exposed to (4 hr or 10 hr; sunlight functioning as a natural variable in temperature, UV irradiation, and light). Surprisingly, although the same species, female N. ocellatus from the highland habitat did not demonstrate this discrepency between sunlight exposure times.

What does this mean? The authors of this paper predict that in N. ocellatus, the lowland-dwelling lizards are more likely to give birth to female lizards than male lizards when temperature is higher. Lowland female lizards born earlier (as a result of warm temperatures earlier in the year) have a reproductive advantage over lowland female lizards born earlier in the year. Neither highland lizards or male lowland lizards experience a similar boost from being born earlier (resulting in more females in lowland species in warmer years). For the highland lizards, the overall temperature is colder and there is not a significant reproductive advantage to being born earlier in the year. Additionally, the paper revealed a possible mechanism for species divergence (i.e., cladogenesis) - that of environmentally-sensitive evolution of sex-determination systems.

Remember our question about predicting the sex of future offspring?  The authors also suggest that if the warming trend continues in the species' habitat, more females will be expected. Hypothetically, lowland N. ocellatus mothers can plan on more female offspring in their future (assuming it remains an evolutionary stable strategy for the species). Greeting card companies for newborns take note!

It a Gril! (via Cake Wrecks)

The Great Turtle-Egg Evacuation

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The Deepwater Horizon oil spill is a very, very sad story. No matter how you look at it, the whole thing is spelling disaster.

What is surprising to me is how the event is being labeled as an ecological disaster by the mainstream media. Even though the explosion of the oil platform has left 11 dead (plus 2) and 17 injured, these facts have been essentially forgotten as the yet-contained oil continues to spew into the Gulf of Mexico and its surrounding shoreline. The focus is not unwarranted in most respects, as the consequences of this input of crude into the Gulf and associated cleanup efforts have and will have staggering effects on the ecology of the Gulf of Mexico and the Atlantic Ocean.


Unsurprisingly, an already-struggling effort for effective sea turtle conservation is being hit with very difficult decisions about what to do. Several species of adult sea turtles are running the risk of being cremated alive when caught inside oil slicks being burned. Additionally, as eggs hatch from nests on the beaches of the Gulf, juvenile turtles would face thousands of miles of oil-polluted water in the most vulnerable time of a sea turtle's life.

This last situation is why the US Fish and Wildlife Service, the National Marine Fisheries Service, and the Florida Marine Fisheries Service have developed a plan to relocate an estimated 70,000 sea turtle eggs from almost 800 beaches along Alabama and Florida. Read more here: The Great Turtle-Egg Evacuation


The plan is very risky for turtles inside eggs. As the article states:
"[...] within 12–24 hours of the eggs being laid, embryos attach to an oxygen-supplying membrane. So any movement of the eggs could cause detachment and death [...]."
A former student from my university completed a series of research projects on sea turtle conservation in the last few years which illuminated my perception of the effectiveness of current conservation efforts. This last point about the eggs dying if moved at the wrong point in time is correct, and is a major concern in these operations.

This topic has been a hot one in many email listservs I am subscribed to (especially C-TURTLE), and the point most interesting to me in all of this is the question of how the relocated hatched juveniles will respond to being transported to beaches several hundred miles from where they were laid. The previously-linked article continues to talk about potential affects of this operation on the relocated turtle's behavior:
Moving the eggs is not generally viewed as problematic. "We have adequate data showing that eggs moved with competence at that age have no difference in survivorship to those not moved," said Mike Salmon, a biologist at Florida Atlantic University in Boca Raton. 
But the release could be another matter. "What we don't know is what impact it might have on other aspects of behaviour," says Salmon. 
"The $64,000 question is, if you take hatchlings that would normally emerge in northwest Florida to the east coast," he said, "will they return there, or to the northwest, where they should go?" Because scientists don't know for sure whether imprinting occurs in the nest or after emergence, this remains a mystery.
This point is one where conservation, ecology, and ethology intersect. My favorite! I anticipate some interesting research will come out of this project, especially if local behavioral research-heavy universities (e.g., University of Florida) are asked to become involved. So much is known about sea turtle navigation and spatial perception, but I do not know of any test which has analyzed how moving recently hatched eggs 500 miles away affects the survival of individuals. Normally, this is not a practical situation which would not require testing (and thus, I see why there is a paucity of research on this specific topic).


Finally, it is worth noting that Heppell et al. (1996) found that the most effective contributors to sea turtle conservation were not efforts directed towards very young sea turtle (particularly 'headstarting', or catching recently hatched individuals and raising them for a year before release). Instead, turtle excluder devices (TEDs) attached to shrimp trawling nets offer the greatest positive effect on their survival. I wonder how meaningful this project to move ~70,000 eggs will be in light of these results.


Thank you for reading, I hope you are doing your part to support relief and clean-up efforts in the wake of this ecologically-disruptive event.

Addendum: I could insert lots of opinion on the oil spill, but I'll pass for two reasons: 1) I'm not a geologist, and 2) no one wants to read my whining (not even me). You can read more about sea turtle headstarting here.

Museum of Living Art (MOLA) - Now Open

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As summer approaches, I am getting mixed news about what I'll be doing for the next few months. I had applied to several internships, but none of them had positions open :/

One place that I am interested in is the Forth Worth Zoo. I had a post at the beginning of the year which described the zoo and a new exhibit - the Museum of Living Art (MOLA). This exhibit replaces their Herpetarium built in 1960.

Upon visiting the FW Zoo's website, I see that MOLA opened in March of this year!

Check out their over-the-top promotional videos here or here.

The size and scope of the exhibit are phenomenal. The 30,000 sq. ft. facility houses (at current) around 1,000 individuals representing a hundred different species of reptiles and amphibians.

I'm super-pumped! I'll report in when I have the chance to visit them next.

Update: When searching for images for this article, I spotted one of my pictures in the top results of a Google Search. Moving up the food chain. We also recently hit 1,000 pageviews. Hooray!:

Lots of Stuff - Videos, Snake Bites and More!

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Here's the setup.  Whenever I find something I think would make an interesting post on this blog, I bookmark it with intentions of writing an article at some point.  That happens for the things with some substance, but over time, I have accumulated all kinds of internet knick-knacks that I'd like to share in one large post.




  • Here's a neat one. On this website, you can view high-quality, color, streaming video of a nesting Red Tailed Hawk (tipoff from here). The nest is located in Philadelpha, PA at the Franklin Institute Building. Here's a screencap of what I saw when I visited :)
  • A study has found that denim denim may guard against rattlesnake bites. Read the fine print, as the study was just measuring the amount of venom that was injected into warm saline-solution filled gloves - not necessarily accounting for physical damage or psychological damage (I think you'd be a bit freaked out if you were bit by a poisonous snake!). Nonetheless, it's an interesting read (especially since I'm always wearing denim jeans).
  • A species of frog thought to be extinct in the wild for 30 years has been rediscovered on farmland in the Southern Tablelands of New South Wales state of Australia. The Yellow-Spotted Bell Frogs are quite adorable and the article notes optimism for similarly-"lost" species. Seven of Australia's 216 known species of frogs have disappeared in the last thirty years.

Hope that was enough for you! I'll continue updating throughout the week as I tactfully do not do homework before finals week.

Lizards 'Shout' Against A Noisy Background

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One of my interests as an ethologist is animal communication. I can find almost infinite wonder in pondering how whales thousands of miles away can tell each other about their location for breeding, how bees communicate food locations, or how birds signal conspecifics for a predator alert.

This interest was one reason why I took pause at an article published via ScienceDaily a few years ago.

The researchers, Terry Ord, Richard A. Peters, and Barbara Clucas, recorded anoles in more and less visually "noisy" environments.  They found that lizards modify their visual displays in more visually busy environments.

But what are we talking about? If you've never seen lizard communication, it's pretty ethereal. Anoles do not exhibit all of reptile communication, but here are some videos of bearded dragon arm waving and head bobbing.





Visual displays are very important to mostly-mute squamates (snakes and lizards). For example, anolis lizards use colorful dewlaps while other lizards display colorful underbellies:



Article - Huge Monitor Lizard Species New to Science

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What a find!

Ethnobiologists in the Philippines recently discovered a whopper of a lizard. Now introducing the Northern Sierra Madre Forest Monitor Lizard (Varanus bitatawa)! This large (~10 kg) lizard is apparently one of only three known fruit-eating species in the world.

To learn more, check out this article from ScienceDaily.

According to this article, the fruit-eating lizard lives in the trees on the northern Philippines island of Luzon. The species was probably so difficult to find because the lizard has actually been hunted by humans (their main predator) for so long that the behavior of the species has become highly secretive and skittish.

Nowadays, discovering large vertebrate animal species is a fairly rare event (when one omits genetic testing, I suppose). That the lizard is fruit eating and quite brightly colored makes the find even more remarkable.

That's what you get for being observant :)


EDIT: Fixed broken link. Sorry for the confusion.

Article - All-Female Lizard Species Crosses Its Own Chromosomes

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Today's article is an interesting one, even if it might require a bit of background in genetics.

From grade school, you probably know that in sexually-reproducing species (includes most animals), a combination of male and female DNA (in the form of compressed chromosomes) crosses and creates new combinations of genetic information. This process is very complex from an evolutionary standpoint, but has survived because of the genetic resistance to random change it affords.

Now read this interesting article published via Scientific American.

When it comes to the sexual behavior of lizards, things get weird, but this article describes an interesting scenario where female checkered whiptail lizards (Aspidoscelis tesselata) are capable of carrying two sets of chromosomes and crossing them over to create a new combination of genetic information - without a male individual! This is new research to the field of reproduction without sex (i.e., parthenogenesis). This research subtly suggests that in well-adapted species, parthenogenesis could be carried out for far longer than previously hypothesized.

Why would a species even adopt parthenogenesis as a strategy of life? First off, remember that evolution is blind and without a cause. Then postulate that in environments where finding mates is especially taxing on a species, individuals that are able to create their own offspring would have a significant advantage in passing along their genes. Often, it is the case that parthenogenesis involves female individuals asexually creating clones of herself and occasionally asexually producing male individuals to add genetic diversity to that population via sexual reproduction. Here is a visual representation of this cycle:


The break from this "normal" parthenogenesis is that now female checkered whiptails have been shown capable of crossing their own chromosomes - seemingly eliminating the need for males in a population. Another interesting note is that in some species exhibiting parthenogenesis, courting behaviors are still observed, even when no males are present. I will be researching this oddity at a later date, but I am gathering that these behaviors increase fecundity (reproductive success) by increasing circulating crucial sex-related hormones released during stimulations associated with courtship (e.g., mounting).

Bird-From-Dinosaur Theory of Evolution Challenged: Was It The Other Way Around?

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You remember being an inocent kid, right? You were told by mom and dad that dinosaurs are extinct and perhaps even that dinosaurs were reptiles. As a young adult, you might have learned that birds evolved from dinosaurs. It seems believable: feathers could be highly evolved scales, and dinosaurs (which could have been endotherms, rather than ectotherms). These topics of thermoregulation in dinosaurs and the question of whether or not birds evolved from dinosaurs have been topics of heated debates amongst paleontologists and scientists for at least the last three decades.


Pretty cool, huh? If you read it, you should consider the findings exciting! There is now more convincing evidence that birds did NOT evolve from theropods (i.e., dinosaurs). This has spurred some debate even among my close friends, and I would be interested in hearing what others have to say on the topic. Leave some comments below and subscribe to the comments to hear replies.


You can read more about feathered dinosaurs here and here.

Lizards Pull A Wheelie

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I've recently discovered an incredible website, Science Daily. The incredible thing about this website is that the cumbersome task of finding interesting science news is changed to being an explorable adventure with new information always just around the corner. This has led me to find a bevy of fascinating articles I will be sharing over many of my next few posts.

One such article, Lizards Pull A Wheelie, piqued my inner cravings for understanding reptilian locomotion (we all  get them once and a while, trust me). I'll be brief, as this article is already a summarization of the research paper "Why go bipedal? Locomotion and morphology in Australian agamid lizards." Essentially, several studies performed by Christofer Clemente indicate that bipedalism (locomoting/moving on two limbs, like humans) has taken shape in many dragon lizard species because they are essentially pulling a wheelie - going so fast that they rear up on their hind limbs (!!!). Their ruling out of other explanations (e.g., evolved behavior, efficient energetics) was impressive, which is what I found most interesting about this article. Go give it a read and let us know what you think.

30 New Frog Species Found in Ecuador

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As a follower of Save the Frog's "Frog Blog," I get interesting articles about amphibian conservation and news from the field of herpetology. One recent post concerned a summary of several newly discovered species recently found in Ecuador, including thirty new species of frogs.

You can read the article HERE.

It continually amazes me that there are so many species yet unknown to science. Maybe more impressive than that is the number of vertebrate species still unknown. If this article interests you, read a couple of posts I've written about my opinions on biodiversity here and here, and also about new species discovery.

Museum of Living Art

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2009 was a rough year for everyone. Possibly the least popular year of the decade. One of the biggest let-downs I experienced in 2009 was the delayed opening for the Fort Worth Zoo's Museum of Living Art. Before I explain, allow me to remind you that my family visited the Ft. Worth Zoo last year with intentions of seeing some progress on this world-class project. Unfortunately, it appeared that delays had pushed its opening to sometime this spring.

What the heck am I talking about, pray tell? Only the construction of the world's most awesome herpetarium (like an aquarium, but for reptiles and amphibians)! This thing's going to be huge - probably the largest in the world (both in square footage, number of species, and possibly number of individuals).

When the zoo's current herpetarium opened in 1960, it held more species of reptiles and amphibians than any other facility. Throughout it's history, the staff have been responsible for the breeding of several individuals, included many rare and endangered species. This new facility will continue their previous vision, but with the world-class resources deserving of their world class efforts. In addition to housing more species than any other facility, the MOLA will continue and expand upon their significant conservation efforts for amphibians (If you would like to know more about their conservation efforts, read this article here).

The MOLA will have several different "habitat" areas for viewing by patrons, including a deserts, swamplands, and rain forests. Just check out this huge list of species the MOLA will be keeping, or should I say curating? If that doesn't get you salivating, you can view the online floor-plan for the new facility which indicates generally what will be exhibited. For zoo activity in the new decade, keep an eye out for the MOLA.

Here are two shinglebacks in the Fort Worth Zoo's current herpetarium. Shinglebacks are highly monogamous (single pair breeders). There are cases of them breeding with their mate (to the exclusion of other individuals) for up to twenty years:

New Species Found Every Day

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Scientists often ask the question "How many species are there currently living on Earth?" How many do you think there are? 50, ooo? 100,000? 1 million? Estimates vary from study to study, but conservative estimates point to 7-10 million species, and other studies claim up to 100 million species. That's a lot!

Certainly, the ability to understand just how many species are currently on our planet is crucial to understanding what changes affect living things. Without baseline information, detecting trends is near-to if not impossible. (For related topics, see my posts on biodiversity here and here).

Although the estimates of the number of species varies so widely (93 million is a huge number, last time I checked), there seems to be a consensus that large and charismatic species are described more completely than, say bacteria or lichens. That is why you may find it surprising to hear that scientists find new vertebrate species all the time. Yep. A recent news article (with beautiful photos) describes species of frogs, geckos, snakes, birds, and even a flowering plant that are all new to science. If that piques your interest, here's another article (again, with great photography)

I have previously commented that taxonomy (the science of naming species) is a dying science and art. This is especially unfortunate in an era when our estimates of the number of undiscovered species on our planet are so massive! In my naive mind, a solution to this problem would be a grassroots effort in the sciences to support taxonomists and the work they do. Fellowships, labs, and doctoral positions should be competitively awarded to taxonomists in academic institutions, not just at Harvard or Oxford, but around the world. This network, coupled with online diversity indices (such as Encyclopedia of Life and GeckoWeb), will aid in conservation and education efforts destined for governmental policy. I feel declines in worldwide biological diversity are worse than eminent global warming (regardless of cause) and the only way to effectively combat those declines is via workable, worldwide diversity indices.

If you're interested in following new species discoveries, try ScienceDaily's New Species News.

Now for some animal photos. We all like those:





Article: Now Hiring Governmental Fact Checker on Python Populations

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I recently read this fascinating article posted on Tampa Bay Online.

If I told you it was an article about reptiles in the Florida Everglades, I'll give you three guesses as to what the article is about. Due to grossly over-inflated media attention, you probably guessed it's an article on invasive Burmese pythons.

From what I've gathered by reading the article, U.S. government agencies are estimating the number of burmese pythons in the Florida everglades to be between ~1,000 and ~200,000 (two degrees of magnitude apart!).

Seriously?

What I hope to draw to your attention in this post is not that burmese pythons are good or bad in the Florida everglades, but that governmental biologists need some fact checkers before pulling on the "statistic crank."

Given the amount of media attention and governmental recognition the issue has received, an accurate (and hopefully conservative) estimate of the number of Burmese pythons and their ability to reproduce is necessary to maintain a non-nuisance level of this species.

A final word: always ensure you can be a responsible, long-term exotic pet owner before making a purchase or taking your neighbor's pet alligator off their hands. It's good for the environment!

Some Hope for Hunted Sea Turtles

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According to an Associated Press article by David McFadden, the Bahamas recently banned the sale or catch of any species of marine turtle.

Culturally popular for human consumption, sea turtles have required this sort of legal protection for too long. The five species of sea turtle inhabiting the waters of the Bahamian waters are listed as either endangered or threatened species. Previous to the bill, only the Hawksbill was afforded any legal protection from harvesting or hunting.

According to an ecoworldy article by Derek Markham:
The new regulations prohibit the harvesting, possession, purchase and sale of turtles, their parts and eggs, as well as the molestation of marine turtle nests, effective September 1st, 2009.
To get to this landmark legislation, several conservation groups played active roles, including: Oceana, The Bahamas Sea Turtle Conservation Group, and The Bahamas Marine Resources Department



According to the AP article, this legislation is unpopular with some proponents of preserving Bahamian culture. Fortunately, according to Jane Mather, co-chairwoman of The Bahamas Sea Turtle Conservation Group, ninety percent of Bahamians do not want sea turtles killed.

The penalties for breaking the ban are not currently determined.

Beautiful Anuran Photos From Vietnam

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Wildlife photographers' challenges are many: know a species, be there, avoid disturbing the species, use the right equipment, and prepare for failure. In my case, failure is simply avoided by taking several photos, but you can't always use such a low-effort solution.

Sometimes you have to go to great lengths to get the right photograph - like going to Vietnam.

I encourage you to experience beautiful frog photos by clicking here.


Additionally, if you have any wildlife photos you feel the whole world needs to see, send them to me at halla(at)southwestern.edu and I'll see what I can do for you.

Review - "The Fascination of Reptiles"

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The Fascination of Reptiles by Maurice Richardson is nowadays innaccurate and historical, at best.

This book is a decent read for the only the most enthusiastic herpetologist.

Reptiles is written from the author's personal experiences as a herp enthusiast, with a fond eye focused on all things reptilian. Species descriptions and anecdotal accounts of reptilian behavior swap places back and forth covering the snakes, lizards, turtles, crocodiles, and alligators. The author's emphasis is extrordinarily heavy on appealing to an assumed-British audience. For example, whole chapters are devoted to the very few British reptiles, while mere paragraphs are allotted to a slew of Indonesian or South American treasures.

A common theme in Reptiles appears to be the author's unrelenting obsession with the degenerative features found in skinks, legless lizards, and burrowing snakes. Truly, it was obnoxious. Evolution does not have a goal or purpose - get over it!

A common flaw in the field of herpetological description is its lack of mention for ancestrally-related reptilians - birds. A mention or two of birds, or even dinosaurs, would make me smile a bit.

Illustrations by Shaun Milne are cute, but you can't help but wonder about their accuracy at times. Some sense of scale in the plates and drawings would have been appreciated.

Chapter topics: Classification and Evolution, The Living Ancestor, The Lizards: Suborder Sauria, British Lizards at Home, The Marvellous Chameleon, The Snakes: Suborder Serpentes, Pythons and Boas, Poisonous Snakes [2 chapters], British Snakes at Home, The Chelonians: Tortoises and Turtles, The Crocodilians, Some Reptiles of North America, Herpetologists I Have Known, Reptiles In Captivity, and An Anthology of Reptilian Belles-Lettres.

Overall: 2/5 - a fun read, but not particularly useful or entertaining

Field Trip - To the Forth Worth Zoo!

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My family took a trip to the Fort Worth Zoo just after school was out. Rather than drone on and on about a zoo many of you have never visited, I'll post some pictures. For larger images, click on the thumbnails.















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