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Snake Fungal Disease – Conservationists Fear Emerging Disease Epidemic

Recently I reported on a study that documented declines of 50-90% in 17 populations of 8 snake species (please see article linked below).  These findings brought to mind the global amphibian decline that was first uncovered in 1990.  Since then, an emerging disease caused by the fungus Batrachochytrium dendrobatitis has likely caused the extinctions of over 100 frog species.  Researchers seeking to avoid a similar crisis among the world’s snakes have now identified an emerging illness, Snake Fungal Disease, as cause for serious concern.  Associated with a newly-described fungus, Chrysosporium ophiodiicola, the disease has been found in several species in 9 states (USA), but is likely much more widespread.

Timber Rattler

Uploaded to Wikipedia Commons by Rkillcrazy

New Victims of a New Fungus

The global snake declines mentioned above first came to light in the late 1990’s, but explanations remain elusive.  In 2008, herpetologists became alarmed when Eastern Massasaugas (or Swamp Rattlesnakes) in Illinois and Timber Rattlesnakes in New Hampshire showed evidence of an unusual fungal infection.  A fungus (Chrysosporium sp.) that had previously been isolated from captive snakes, but never in the wild, was identified from head lesions on the Timber and Swamp Rattlesnakes.  All of the snakes submitted for study expired.

In April of 2013, the USGS National Wildlife Health Center announced the discovery of a fungus new to science, Chrysosporium ophiodiicola.  This fungus has been implicated in an emerging disease that is now afflicting snakes in the Eastern and Midwestern USA.  Increasing numbers of snakes showing evidence of infection have been found by USGS biologists, who fear that the disease may devastate snake populations. Read More »

Salamanders and Cell Regeneration – How Do They Regrow Limbs?

As anyone who has attempted to lift one by its tail knows, salamanders and newts can discard these body parts with no ill effect.  In time, we learned that they can regenerate not only tails, but also heart, brain and spinal cord tissue…parts of any organ, it turns out, can be regrown.  Furthermore, researchers describe the cell regeneration process as “perfect” – normal function is restored, and there is little if any scarring.  Salamanders hold special interest for me.  I’ve kept a great many species in zoos and at home, have studied several in the wild, and even had the happy opportunity to write two books on their care.  I’ve always hoped that we would uncover the key to their mind-boggling abilitiesI’m happy to report that a groundbreaking discovery has now given us some answers, and may lead to research of immense benefit to people suffering from a wide range of diseases and injuries.

Axolotl, natural coloration

Puloaded to Wikipedia Commons by Stan Shebs,

Why Study Salamanders?

Internally, amphibians and people show many similarities.  And while most are aware of the medical significance of frog studies and dissections, few people know that the real amphibian research star is the Mexican Axolotl, Ambystoma mexicanum.  Studies of this unusual aquatic salamander have led to important advances many fields, including gene expression, neurobiology and limb/organ regeneration. Read More »

Green Anole Intelligence – Researchers Shocked by Lizard Brainpower

I’ve been fascinated by Green Anoles, Anolis carolinensis, since childhood – way back when they were sold as “American Chameleons”.  Although they are often ignored by experienced keepers, I have long featured Green Anoles and related species in zoo exhibits, where they never failed to intrigue visitors (and yours truly!).  Now, it seems, they are also impressing herpetologists with learning abilities that rival those of some birds.  The performances of anoles (two of which did so well that they were dubbed “Plato” and ‘Socrates”) tested at Duke University have challenged the stereotype that small lizards have limited intelligence and problem-solving abilities.

Learning, Adapting and Remembering…

Green anole

Uploaded to Wikipedia Commons by IraEskins

The species studied was the Emerald or Puerto Rican Anole, Anolis evermanni.  It seems likely that Green Anoles and others sharing similar lifestyles will be found to possess like abilities; further research is in progress.

The anoles were presented with a problem that would not be faced in the wild…relying upon instinct would not provide a solution.  The challenge presented was to retrieve an insect that had been placed beneath a plastic lid.  Emerald Anoles figured out how to lift the lid more quickly than did the birds that were tested, requiring three less trials.  What’s more, the anoles had only one test each day, compared to the given the birds, so the lizards had less experience, and needed to remember their successes or failures for a longer period of time.

When multiple caps of different colors were added, the savvy anoles always chose the correct cap, apparently having associated the color or brightness with a reward.  The researchers then switched tactics, placing the insect beneath a lid of a different color, and leaving the original correct choice bare.  All of the anoles made initial mistakes, but ‘Socrates” and “Plato”, the individuals mentioned earlier, quickly learned to ignore their earlier lesson and consistently chose the correct lid. Read More »

Venomous Pythons? – Snakebite Victims Benefit from New Research

In recent years, researchers have found toxins in a wide array of snakes and lizards formerly believed to be harmless…even the Bearded Dragon is not above suspicion (please see below), but venomous pythons?  While working at the Bronx Zoo, I was several times called upon to assist in confiscating snakes that had appeared in the pet trade before we learned of their potentially lethal venom (i.e. Asian Watersnakes, genus Rhabdophis). All evidence of toxicity must be taken seriously…bear in mind that both the Boomslang and Savanna Twig Snake were thought to be harmless until each killed a prominent herpetologist!  The recent discovery of toxins in the mucus of certain pythons poses a unique and unexpected concern for snakebite victims.

Boomslang

Uploaded to Wikipedia Commons by CorneliusA

Python Venom

Studies at the University of Queensland have revealed the presence of toxins in the mucus of several python species.  Described as “relic venom”, they occur in only trace amounts. In common with many other snakes, pythons may have relied upon venom at some point in their evolutionary history.  Although they no longer utilize venom to overcome prey or defend themselves, pythons continue to produce some toxic compounds.  While some snakes bear toxins that target specific animals (i.e. Tentacled Snakes, Erpeton tentaculatum, which prey upon fish), python toxins seem to have no use, and pose no danger to people.

The toxin molecules thus far identified in pythons differ from those found in any known venomous snake.  Being so chemically unique, they are of great interest to those seeking to develop new chemical compounds and medicines. Read More »

Black Mamba Memories – Working with one of the World’s Deadliest Snakes

As a small boy, I devoured the books of Messrs.’ Ditmars, Kauffeld, Whittaker, Sanderson and others who sought out snakes in their natural habitats. The formidable Black Mamba, (Dendroaspis polylepis), accorded respect by all, was given a special place of honor by legendary snake man C.J.P. Ionides in Mambas and Maneaters. Although I was eager to expand my snake hunting experiences, these authors convinced me that this longest of Africa’s venomous snakes was better observed than handled. Fate intervened, however, and I wound up working closely with what has been described as “Africa’s deadliest snake”. Accounts of the recent escape of a Black Mamba from the Pretoria Zoo brought an experience of my own back to mind…

Mamba striking

Uploaded to Wikipedia Commons by Tad Arensmeier

Handling Mambas and Cobras

Zoo-based reptile keepers such as I handle thousands of venomous snakes over the course of their careers. A snake hook generally fits the bill for routine tasks. The Black Mamba, King Cobra and several related species, however, present special challenges, especially when they reach full size. Quick, high-strung, and seemingly more alert and intelligent than others, many Elapids (cobras, mambas and their relatives) are difficult to move via snake hooks….all old reptile keepers have their stories. You can read about my adventures with an escaped King Cobra in this article.

I was fortunate in having had the benefit of working with several older, well- experienced keepers, and had no illusions about “proving” myself when it came to cobras and mambas. I feel that “discretion is the better part of valor” where they are concerned, a belief confirmed by observations made in the course of responding to many snakebite emergencies over the years. Whenever possible, I relied upon shift cages or other “tricks” (please see article below) when I needed to move a mamba.

Read More »

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