That Reptile Blog » Snakes

Snake Fungal Disease – Conservationists Fear Emerging Disease Epidemic

Frank Indiviglio — Fri, 14 Jun 2013 13:32:16 +0000

Hello, Frank Indiviglio here. 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.

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.

Is Snake Fungal Disease the “Next Chytrid”?

If the examples set by “Chytrid” (amphibians), White-Nose Syndrome (bats), and other emerging diseases hold true, the USA’s snakes may face a bleak future. Already, a 50% decline in one population of Timber Rattlesnakes has been credited to Snake Fungal Disease. Unfortunately, the lack of long term studies, and the difficulties involved in finding ill snakes, hinders efforts to understand the disease. In fact, it is not even known if Chrysosporium ophiodiicola actually causes Snake Fungal Disease. It is the only species that is always present on afflicted snakes, but other fungi sometimes occur as well.

Snake Fungal Disease has been documented in 9 states, including New York, Minnesota, Florida, New Jersey and Wisconsin, but is believed present but unidentified in others. In addition to the species mentioned earlier, Eastern Racers, Eastern Rat Snakes, Northern Water Snakes, Milk Snakes and Pygmy Rattlers have been infected. Symptoms of the disease include thickened skin, abnormal molts, subcutaneous nodules, ulcers, cloudy eyes (not associated with a molt), scabs or crusted skin, and swelling about the face.

Uploaded to Wikipedia Commons by Trista Rada

Your Input and Observations Needed

The USGS is seeking input from those who keep snakes and observe them in the wild. As we know very little about Snake Fungal Disease and its possible effects on snake populations, I urge anyone who may have useful observations to please post a note below. I’ll then be able to advise you as to how best to proceed.

Please check out my posts on Twitter and Facebook. Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Venomous Pythons? – Snakebite Victims Benefit from New Research

Frank Indiviglio — Tue, 14 May 2013 15:40:59 +0000

Hello, Frank Indiviglio here. 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.

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.

Implications for Snakebite Victims

Potential problems arise when a person is bitten by a snake that has not been identified. In such cases, a highly-sensitive venom detection kit is used to determine if toxins are present in the victim. The harmless toxins found in python mucus can trigger a positive response following a python bite, and may result in the unnecessary administration of antivenin (medicines used to counteract snake venom).

In addition to being extremely expensive, antivenin triggers violent allergic reactions in many people. If not treated properly, anaphylactic shock and death can result. Unnecessary treatment also depletes antivenin stocks, which are often difficult to replace. The potential for such problems is greatest in Australia, which is home to a wide variety of both pythons and venomous snakes.

Famous Herpetologists Killed by “Harmless Snakes”

Uploaded to Wikipedia Commons by TimVickers

Until rather recently, snakes in the family Colubridae (which contains those “typical snakes” with which most people are familiar) were considered relatively harmless. The family’s venomous members are rear-fanged, and it was believed that their seemingly ineffective venom-delivery systems posed little threat to people.

In 1957, however, world-renowned herpetologist Karl P. Schmidt was bitten by a Boomslang (Dispholidus typus) while working at the Chicago Field Museum. At the time, the Boomslang was not believed to be dangerously-venomous. Unconcerned by the fact that a single fang had punctured his thumb, Mr. Schmidt took notes on his symptoms and did not seek medical treatment. He expired the next day. By the early 1970’s, several other deaths had been attributed to this African Colubrid.

Another African rear-fanged snake, the Savanna Twig Snake (Thelotornis capensis), took the life of another prominent herpetologist, Robert Mertens, in 1972. Once considered harmless, this species had been implicated in several deaths by 1972. As any snake enthusiast knows, Mr. Mertens’ work is beyond reproach, but for some reason he decided to hand-feed a captive Twig Snake. He succumbed to the resulting bite after a period of three weeks.

Other Dangerous Colubrid Snakes

Fatalities have also been attributed to bites from the Yamakagashi (Rhabdophis tigrinus), a semi-aquatic Japanese snake. I was involved in confiscations of several related species in the late 1980’s and early 1990’s, when they sometimes appeared in US pet stores.

Uploaded to Wikipedia by One dead president

The bites of a number of other “harmless” snakes have caused severe reactions, and all may be capable of causing human fatalities. In fact, the venom of the Blanding’s Treesnake (Boiga blandingi) is as toxic as that of certain cobras. It and related species, such as the Mangrove Snake – a high strung species that I found very difficult to work with in zoo exhibits – should be treated with extreme caution. Other potentially deadly species include Latin America’s Road Guarder (Conophis leneatus) and various Racers in the genera Alsophis and Philodryas.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Africa’s Deadliest Snake? Black Mamba Habits, Venom and Behavior

Frank Indiviglio — Tue, 07 May 2013 18:11:37 +0000

Hello, Frank Indiviglio here. As any experienced reptile enthusiast knows, accounts concerning the size and aggressive nature of various snakes are usually highly exaggerated. The Black Mamba, however, comes close to living up to the legends that surround it, and has long been among the most feared of all African snakes. In the course of a lifetime spent working with venomous snakes in the wild and captivity, I’ve come to regard it as deserving of a special degree of respect. Today we’ll take a look at its natural history and behavior.

Description

The Black Mamba is the longest of Africa’s many venomous snakes. It is slender in build and averages 8-9 feet in length, but 14 footers have been recorded. Also very agile and fast-moving, several individuals have been clocked at 12.5 miles per hour. Black Mambas often travel about with the head held high, in a manner similar to that of North America’s Black Racer.

Uploaded to Wikipedia Commons by Tad Arensmeier

The “black” part of its common name is derived from the color of mouth’s interior, which is displayed when the animal is threatened (North America’s Cottonmouth behaves in a similar fashion). The body color may be various shades of brown, olive or gray, but is never black.

Venom

Classified with cobras, sea snakes, coral snakes and related species in the family Elapidae, the Black Mamba produces highly toxic venom that acts upon the nervous and circulatory systems. An adult mamba can deliver 100-120 mg of venom in a single bite. Since the lethal dose for humans is a mere 10-15 mg, the severity of a bite cannot be over-estimated. The danger is compounded by the fact that Black Mambas often administer multiple bites in rapid succession.

Before the development of antivenin, Black Mamba bites were almost always fatal. Unfortunately, antivenin is not available to those Africans most at risk. In fact, of the 1.5 million people bitten by venomous snakes annually in Sub-Saharan Africa, only 10% are treated with antivenin; at least 7,000 people die as a result, while another 14,000 suffer limb amputations (please see article linked below for further information). Concerning Black Mamba bites, the fatality rate remains at or near 100% in the many rural areas that are not adequately supplied with antivenin.

Black Mamba venom produces morphine-like effects under certain conditions and is being studied for possible medicinal use.

Threat and Attack Behavior

According to most observers, mambas will flee if able when approached by people. Much to my chagrin, zoo specimens tend to stand their ground, as retreat options are limited! The same may be said of those surprised in buildings or other enclosed areas. Drawn by rodents and nesting birds, Black Mambas are not uncommon in and around buildings in some regions. There are well-documented instances of multiple deaths being caused by single Black Mambas that have fallen from roofs onto people sleeping below.

Disturbed mambas raise the first third of the body off the ground and flare a narrow skin flap that lies along the neck. The mouth is held open, exposing the jet black interior, as the animal hisses and moves its head from side to side.

Uploaded to Wikipedia Commons by deror avi

Range

Two subspecies have been described. Dendroaspis p. polylepis ranges from Ethiopia to South Africa. A widely separated population occurs in parts of tropical West Africa, but the extent of this part of the range is not well-studied. D. p. antinori is confined to Ethiopia, Somalia, northern Kenya and northern Uganda.

Three additional mamba species, all highly arboreal, also occur in Africa – the Eastern Green Mamba (D. angusticeps, please see photo), the Western Green Mamba (D. viridis), and the Jameson’s Mamba (D. jamesoni).

Habitat

The Black Mamba inhabits open forests, wooded savannahs, rocky thorn scrub and the fringes of the Kalahari Desert, but also colonizes farms and villages. Although largely terrestrial, it climbs well and often shelters in tree hollows, thatched roofs and arboreal termite mounds.

There is some evidence that specific home ranges are maintained, and that the same shelter may be utilized for quite long periods of time.

Diet

Birds, mammals (shrews, hyrax, rodents, bats), snakes, and lizards

Activity

In most regions, Black Mambas are diurnal, but seek shelter during the hottest part of the day. There is evidence of nocturnal and crepuscular activity patterns among some populations as well.

Uploaded to Wikipedia Commons by Gerhardt Nieuwoudt

Reproduction

Males wrestle for dominance during the mating season (please see photo). Females deposit 6-17 eggs in mammal burrows, termite mounds, tree hollows and similar sites. The hatchlings average 15-24 inches in length. Black Mambas grow very quickly, with well-fed individuals reportedly reaching a length of 6 feet within their first year of life.

Status of Wild Populations

Detailed studies are lacking, but Black Mambas appear to adapt well to human presence. Agricultural expansion has increased the likelihood of mamba encounters and bites. Given the danger that this species poses to people, it is likely that efforts to eliminate it from developed areas will continue.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Further Reading

Venomous Snakebite: My Experiences and Global Study Results

King Cobra Care and Natural History

Post from: That Reptile Blog

Africa’s Deadliest Snake? Black Mamba Habits, Venom and Behavior

The post Africa’s Deadliest Snake? Black Mamba Habits, Venom and Behavior appeared first on That Reptile Blog.

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

Frank Indiviglio — Fri, 03 May 2013 15:03:28 +0000

Hello, Frank Indiviglio here. 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…

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.

You Want Me to Do What with the Black Mamba?!

But there came I time when, as consultant for the renovation of the Staten Island Zoo’s reptile house, I was called upon to capture a large Black Mamba and ready it for shipment to another zoo. The snake, a large adult, had not been on a snake hook or otherwise manipulated in years. A shift cage was attached to its exhibit, and the exhibit door was not opened for cleaning unless the snake was locked away in the shift.

Snakes in transit are confined in pillow cases or similar cloth bags, which are tied tightly and then placed into a second bag. Generally a straightforward task… but not with an aggressive, 9 foot-long snake that can flip off a snake hook or exit a bag in the blink of an eye!

Uploaded to Wikipedia Commons by Bill Love / Blue Chameleon Ventures / Reptile & Amphibian Photo Gallery

How to Bag a Black Mamba

After some consideration, I decided to lure rather than force the mamba into a bag. I found a bag of the right size and secured it with duct tape to the opening that led from the exhibit into the shift cage. I then acclimated the snake to feeding within the bag. Black Mambas have fast metabolisms by snake standards, and generally consume quite a bit more food than similarly-sized individuals of other species…hatchlings have been known to reach 6 feet in length within by within one year. Hunger can, therefore, sometimes be used to manipulate them.

You can bet I kept our Black Mamba very hungry prior to shipment! This is standard practice when shipping any snake, as stress can induce regurgitation and related problems, but to be honest I was far more concerned with my stress levels than the mamba’s! When it came time to confine the snake, I rubbed the inside of the bag with a mouse and opened the shift door. Happily, the mamba shot it without hesitation.

I was careful to secure the bag’s opening with a long handled tong, after which I lifted the now violently-moving package into a large plastic garbage can. As is done when packing all snakes, I pulled the neck and 2 feet or so of the bag out of the can, and then placed the can’s lid securely on top. Thus, the snake was confined in that part of the bag which remained within the can, and the lid prevented it from reaching the bag’s neck (or my hand). I could now safely tie the bag by hand, and then secure it further with a cable tie.

I think that some of my younger co-workers would have preferred a more dramatic capture, but I was quite pleased with myself (as was the zoo’s curator and the doctor who had been placed on notice at the local hospital!).

Natural History

Occasionally approaching 14 feet in length, the Black Mamba is the longest of Africa’s venomous snakes, and its venom is among the most toxic to be found on the continent. Add to this a wide range, the ability to colonize farms and villages, and a propensity to bite multiple times in quick succession when threatened, and it becomes clear why this a creature of much concern and deserving of detailed study. Yet it remains difficult to separate mamba fact from fiction. I’ll cover Black Mamba lore and natural history in the near future.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Further Reading

Snake Hunting with Romulus Whittaker

Snake Escapes: Recapturing Cobras and Others

Post from: That Reptile Blog

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

The post Black Mamba Memories – Working with one of the World’s Deadliest Snakes appeared first on That Reptile Blog.

Odd and Giant Snake Meals – Sticks, Antelopes, People, Siamese Cats…

Frank Indiviglio — Wed, 24 Apr 2013 20:28:24 +0000

Hello, Frank Indiviglio here. Many interesting reptile field research reports are published in professional journals that are not available online to non-subscribers. Fortunately, I’ve long had access to many of my favorites, including Copeia, Herpetologica, and Herpetological Review. From time to time I like to provide summaries of interesting reports that I have read and enjoyed. Today’s article covers some very unique snake feeding observations drawn from recent publications and my own experiences in the field and among zoo animals. Please be sure to post your own observations below, thanks.

When Prey Exceeds Predator’s Mass

The largest snake meal that I’ve personally witnessed was a 60 pound White-Tailed Deer taken by a 17 foot-long, 215 pound Green Anaconda, Eunectes murinus, in Venezuela. A 130 pound Impala consumed by an African Rock Python, Python sebae, is the largest fairly reliable meal I’ve been able to document (please see article linked below).

But in terms of the ratio of prey size to snake size, a Red Duiker (small antelope) eaten by a Gaboon Viper, Bitis gabonica, beats most accounts hands down. The antelope outweighed the snake by 4%! In addition to being the largest meal recorded for this species, this is also the first record of an ungulate being taken by a Gaboon Viper in South Africa. I’ve worked with Gaboon Vipers in zoos, and know how well-adapted they are for taking large, infrequent meals, but I was still quite surprised by this observation.

The Oddest Snake Meal – a Stick!

Certain snakes specialize on frog eggs, centipedes, snails, eels, crayfish and other “unusual” foods. On the other hand, I have observed Green Anacondas eating other Anacondas, Spectacled Caiman, birds, fish, Capybara, turtles and deer…one even grabbed a friend of mine in what surely was a feeding and not a defensive response (please see this article).

But the most unusual snake meal I’ve read of in recent years was enjoyed by a Coachwhip Snake in Arizona. Researchers observed the animal biting off a small section of a tree branch. This was dropped, but it soon broke off another and swallowed it! The observers noted that the branch resembled a Fence Lizard, and that Australian Brown Snakes will attack motionless, unscented skink models. So appearance may explain this odd behavior. Also, it’s possible that the scent of an animal could have been on the branch in question, but still…

Specialists Breaking the Rules

Two species long believed to be strict dietary specialists recently revealed that they are open to experimentation. The brilliantly-colored Northern Scarlet Snake, Cemophora coccinea, is rarely kept by hobbyists or zoos because of its preferred diet of lizard and snake eggs. A specimen in South Carolina, however, consumed a young, dead Corn Snake with which it had been temporarily confined.

The Southern Hognosed Snake, Heterodon simus, is widely “known” to be a confirmed amphibian specialist. In North Carolina, however, a field researcher recorded that a large Ox Beetle grub was consumed by a recently collected adult.

The Western Hognosed Snake, Heterodon nascicus, is known to take a wider range of prey than does its southern and eastern cousins. It favors bird and reptile eggs, but has only been observed hunting on the ground. But a herpetologist working in Arizona recently found an adult consuming the contents of a Lark Sparrow nest located 5 feet above-ground. Considering that this species is fairly common and well-studied, the observer was surprised that this behavior had not previously been reported.

Rarely Documented Prey Items

Although possibly more common than has been recorded, considering the natural history of the species involved, two other notes caught my attention recently. An Eyelash Viper, Bothriechis schlegelii, in Nicaragua was seen to consume a bat, only the third time this has been observed. In Argentina, a Yellow Anaconda, Eunectes notaeus, regurgitated another Yellow Anaconda (and a Cormorant), the first instance of cannibalism reported for this species.

“Picky Eaters”: Muskrats, Eels and other demands

Although Green Anacondas take a wider range of prey than most snakes, many captives are notoriously choosy. One adult under my care at the Bronx Zoo would eat nothing but Muskrats (which I trapped in conjunction with my side job), while another refused lab rats but relished wild-caught Norway Rats (the rats are of the same species).

Yellow-bellied Seasnakes, Pelamis platura, are recorded as taking a very large number of fish species, but several at the Bronx Zoo refused all manner of marine fishes (provided by the NY Aquarium)…only American Eels would do.

People and their Pets

Humans, as far as we know, rarely fall prey to large constrictors. However, an amazing study in the Philippines has documented an unprecedented number of attacks on humans, including 6 fatalities, by Reticulated Pythons. Please see this article for details.

The most audacious feeding incident I’ve uncovered is that of a Siamese cat snatched by a Reticulated Python – from the palace of a former king of Thailand! A friend reported that while he was employed at the Singapore Zoo, a free-ranging Reticulated Python consumed one of his Cape Hunting Dogs. Please see the article linked below for further details.

Please check out my posts on Twitter and Facebook. Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

St. Lucia Racer, World’s Rarest Snake (Population 11) is Rediscovered

Frank Indiviglio — Thu, 07 Mar 2013 16:20:17 +0000

Uploaded to Wikipedia Commons by Postdlf

Hello, Frank Indiviglio here. The St. Lucia Racer or Ornate Ground Snake, Liophis ornatus, has the unenviable distinctions of being both the world’s rarest snake and the species with the smallest range…it may even be the rarest creature on the planet. The entire population – 11 individuals at last count – is confined to a 30 acre Caribbean island off St. Lucia.

Ever since reading Archie Carr’s wonderful books as a child, I’ve been drawn to the Caribbean’s islands and coastlines. As luck would have it, I eventually found myself working at Tortuguero, Costa Rica – the very site where much of his ground-breaking Green Turtle research was done. There I became hooked on the region’s fantastic array of creatures, and endeavored to become familiar with as many as possible. In time, I tagged Leatherback Sea Turtles on St. Croix, collected Bahaman Brown Racers, Alsophis vudii, on several islands, and vowed to find again a large, flying Mole Cricket that once stopped me in my tracks on St. Lucia. Unfortunately, Caribbean animals suffer some of the world’s highest extinction rates. In fact, the St. Lucia racer was “officially extinct” for nearly 40 years. Happily, we now know that it still holds on…but just barely.

“Hello Mongooses…Goodbye Snakes”

The St Lucia Racer, known locally as the Kouwes, was once quite common. That changed in the late 1800’s, when Asian Mongooses were imported from India to battle the Black and Norway Rats that were ravaging the cane fields (a naturalist’s journal from that time recounts that the British officer responsible, unsure of the proper plural form of “mongoose”, wrote his superior with this request: “Please send a mongoose” – and while you’re at it, please send several more”!).

The diurnal mongooses rarely encountered the nocturnal rats, but they made short work of many of the island’s reptiles, including the racer. Also facing threats from habitat loss due to goat grazing and development, racer populations plummeted, and the species was declared extinct in 1936.

Intelligent and adaptable, the Asian Mongoose has devastated amphibians, reptiles, invertebrates, birds and small mammals throughout the West Indies. I saw them frequently on St. Croix, where they have even learned to locate the deep-set nests of Leatherback Turtles. Two St. Lucian snakes, the endemic St. Lucia Fer-de-Lance and the St. Lucia Boa (Boa constrictor orophias), exact revenge by occasionally indulging in a mongoose dinner, but this has no real effect on their numbers.

Uploaded to Wikipedia Commons by Antonio de Castro Junior

A Species Resurfaces

The St. Lucia Racer remained “extinct” until 1973, when a single specimen was found on Maria Major, a tiny, mongoose-free island off St. Lucia. But joy over the species’ rediscovery was short-lived, and after years without further sightings it was again feared to be extinct. In 2011, however, biologists from the Durrell Wildlife Trust and other organizations made a detailed survey of the island, and in the process they turned up 11 St. Lucia Racers. The snakes were outfitted with transponders and released back on Maria Major, which is now protected as a wildlife reserve.

St. Lucia Racers spend much of their time in lizard burrows among rocky thorn scrub and cactus thickets, and hence are difficult to locate. Most researchers put the total population at no more than 18, but only 11 have actually been confirmed.

Very little is known about the St. Lucia Racer’s natural history, and nothing of its reproductive biology, so captive breeding is not considered an option. There is some evidence the eggs of lizards such as the St. Lucia Whiptail (Cnemidophorus vanzoi, please see photo) make up much of its diet, but it likely takes lizards, frogs, small mammals and birds as well.

St. Lucia’s Other Reptiles and Amphibians

St. Lucia is home to approximately 28 reptile and amphibian species, only 19 of which are native. Seven of these, including the St Lucia Fer-de-Lance, Bothrops caribbaeus, the St. Lucia Thread Snake, Leptotyphus bruilei, the Cribo, Clelia errabunda, and the St. Lucia Racer, are endemic. At six inches in length and a mere 1/8th inch in width, the St. Lucia Thread Snake is the world’s second smallest serpent (another Caribbean island, Barbados, is home to the world’s smallest snake, L. carlae; please see photo and article linked below).

Unfortunately, six of St. Lucia’s native species are likely extinct, but detailed surveys are needed to confirm this. Those believed to have vanished from St. Lucia are the Antillean Skink, Maybuya maybouya, the Antiguan Pygmy Gecko, Sphaerodactylus elegantulius, the Lesser Antillean Pygmy Gecko, S. vincenti, the Mountain Chicken (a relative of the Smoky Jungle Frog), Leptodactylus fallax, the Martinique Whistling Frog, Eleutherodactylus martinicensis, and the Cribo. In addition, 5 subspecies unique to the St. Lucia are threatened with extinction.

Another Caribbean Rarity

Until being displaced by the St. Lucia Racer, the Antiguan Racer, Alsophis antigua, was considered to be the world’s rarest snake (please see photo of related Antilles Racer). Driven to the brink by mongooses, goats and rats, only 50 remained by 1999, and the species was declared extinct 1936 (and again in 2005). Fortunately, a small population was recently found on mongoose-free Great Bird Island. Predator control and relocation programs have increased the total number of Antiguan Racers to 500+ individuals on four islands.

Please check out my posts on Twitter and Facebook. Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,
Frank Indiviglio

Snake Conservation in 2013 – The “Year of the Snake” Begins

Frank Indiviglio — Tue, 12 Feb 2013 18:15:38 +0000

Hello, Frank Indiviglio here. In 2010, I highlighted a study that documented steep declines in a number of snake species. Despite disturbing similarities to the “Disappearing Amphibian Crisis”, the snake situation seems not to have generated widespread concern. In my own career as a herpetologist, opportunities to become involved in snake conservation were also limited. Although I was fortunate enough to work in programs designed to bolster the populations of several species, including Green Anacondas, Indigo and Hognose Snakes, most such efforts were short-lived. I was pleased to learn, therefore, that a partnership of several major conservation organizations has made the plight of the world’s snakes a priority for the year 2013.

The Year of the Snake…your input needed

The Year of the Snake effort is spearheaded by Partners in Amphibian and Reptile Conservation, and was preceded the Year of the Turtle and the Year of the Lizard. PARC will be joined by the Center for Conservation Biology, the Orianne Society and other notables (please click here for a complete list). In addition to field research and captive breeding programs, public education will be a major component of each group’s activities. I was very glad to see that input from interested non-professionals will be solicited. This is an all-too-rare step, despite the fact that professionals, being limited in both numbers and financial resources, cannot begin to address the myriad conservation needs of the world’s threatened snakes. Please see “What Can I Do”?, below, if you wish to participate.

Threats

Many snakes are declining for well-known reasons, while others face mysterious threats. In several cases, populations have declined by 90% in well-protected areas, a distressing phenomenon that has also been seen among frogs (i.e. the now extinct Golden Toad). I’ll mention just a few below, please write in for further information.

Disease

Most herp enthusiasts are well-aware of the Chytrid fungus epidemic, which has been responsible for the extinctions of 200+ amphibian species. Recently, a fungus that was previously believed limited to captive snakes, Chrysosporium, has been found in wild Timber Rattlesnakes. Although much work remains to be done, there is reason for concern.

Collection

In the USA and abroad, snakes are collected for the pet, leather, medicinal and food trades. Even where, as in the USA, strict regulations are in place, authorities are hampered by poor funding and a lack of management plans. Snakes are extremely difficult to study, and we usually know nothing about the effects of collection (legal or illegal) until drastic declines become apparent.

Habitat Loss and Fragmentation

This problem is well-known to all environmentally conscious people, so I’ll just mention 1 sad statistic contained in a recent PARC newsletter:

Ninety-eight percent of the Longleaf Pine habitat in the USA’s southeastern Coastal Plain is gone. This unique ecosystem was home to many at-risk species, including Diamondback Rattlesnakes and Southern Hognose, Indigo and Pine Snakes.

Invasive Species

Mention invasive species and snakes today, and many people will think of Burmese Pythons in Florida or Brown Treesnakes wiping out nearly all of Guam’s forest birds. But snakes also suffer the effects of introduced species. On Antigua, Black Rats and Indian Mongooses, both non-native, brought the Antiguan Racer (Alsophis antiguae) to the brink of extinction. Once reduced to a mere 50 individuals, the total population now numbers nearly 900, but is far from secure.

The subtler effects of introduced species can be seen in the USA’s Sagebrush Steppe Ecosystem, where invasive Cheatgrass has drastically diminished rodent populations key to the survival of the Great Basin Rattlesnake, Crotalus oreganus lutosus.

Year of the Snake Programs

A number of new conservation efforts have already been initiated, and several established programs have been revitalized.

Although designated as a threatened species by the US Fish and Wildlife Service in 1978, wild populations of the Eastern Indigo Snake, Drymarchon couperi, remain depressed. The Orianne Society has enlisted the help of private breeders, zoos, universities, museums and others in establishing a breeding and management plan.

Populations of the Armenian Viper, Montivipera raddei, and related species have declined by up to 88% in Armenia, Azerbaijan, Turkey and Iran. The St. Louis Zoo has worked to establish 3 preserves in the region, and continues research there.

Limited in distribution to islands within Lake Erie, the Lake Erie Watersnake, Nerodia sipedon insularis, has rebounded and been removed from the Endangered Species List. Control of the invasive Round Goby, which displaced the snake’s preferred prey, and a public education program, led to the recovery.

What’s Next…What can I Do?

The legendary Carl Kauffeld, author of such gems as Snakes, the Keeper and the Kept and Snakes and Snake Keeping, put the Staten Island Zoo on the herp world’s map. I haunted its famed reptile house as a child, but was far too shy to approach the man himself. Decades later, I was thrilled to serve as consultant when the building was renovated. I’m happy to report that we have shifted the collection’s focus back to the rattlesnakes and other venomous species so favored by the famous snakeman. Supporting institutions that study and breed endangered snakes is a wonderful and enjoyable means of assuring their survival.

Partners in Amphibian and Reptile Conservation is soliciting articles, observations, stories, poems and other input from non-herpetologists interested in snake conservation. Please visit the PARC website for further information on participating in their worthwhile efforts.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

2012’s New Reptile and Amphibian Species – Snakes, Frogs and Lizards, Which is Your Favorite?

Frank Indiviglio — Thu, 10 Jan 2013 14:45:01 +0000

Hello, Frank Indiviglio here. An amazing array of newly-discovered reptiles and amphibians grabbed our attention this past year. The unexpected discoveries of an undescribed Leopard Frog in New York City and a Rainbow Skink in an Australian backyard reminded us that wonderful surprises surround us, if only we take the time to look and learn. Frogs that dye human skin yellow, snakes that specialize in eating only eggs or snails, iridescent skinks sporting tails twice their body length…the list is simply astounding. Today I’ll highlight a few that have especially captivated me; please post your own favorites (whether covered here or not) below.

Australian Rainbow Skinks

2012 was designated as the Year of the Lizard by several conservation organizations, so I’ll lead off with 3 new skinks that turned up in Queensland, Australia. The brilliant colors of breeding males lend these tropical lizards their common names (please see article below).

The Elegant Rainbow Skink, Carlia decorata, was well known to folks in Townsville, Queensland, as a common garden resident. Upon taking a closer look, however, herpetologists realized that the colorful creature was an undescribed species.

The Orange-Flanked Rainbow Skink, C. rubigo, was first collected in the arid scrub and open woodlands of eastern-central Queensland.

The Whitsunday Rainbow Skink, C. inconnera, is limited in range to 4 small offshore islands. Formerly considered to be a subspecies of a mainland relative, genetic studies have revealed that it warrants full species status.

“No to the Mine” Snail-Eating Snake, Sibon noalamina

Western Panama’s Tabasara Mountain Range yielded this year’s most “politically-active” species. Its species’ name means “No to the mine”, and was given in support of the indigenous Ngobe People’s battle against the development of their montane rainforest home.

I’ve always been fascinated by snakes that specialize in hunting snails and other unusual (for snakes) prey. This video of a related Sibon species consuming a snail illustrates its unique feeding strategy. Panama’s newly-described Snail-Eating Snake is a Coral Snake mimic, and its bold coloration changes with maturity; I’m wondering if it mimics more than one species over its lifetime?

New York City Leopard Frog

This year’s “most unlikely” new species must surely be the Leopard Frog that was discovered in NYC (shattering, incidentally, my belief that I have observed and kept all herps native to my hometown!).

Uncovered by a sharp-eared Rutgers University student who noted an unfamiliar call one evening on Staten Island, the frog was at first thought to be a hybrid of the Northern Leopard Frog and the Southern (which may be extinct in NY). But it is indeed distinct – and its range, centered (in years past) in the Yankee Stadium area, falls entirely within NYC and its suburbs. I’ve written more about this urban frog here.

Cambodian Kukri, Oligodon kampucheaensis

Oddly-shaped fangs that resemble the distinctive Nepalese kukri dagger lend this unique group of snakes their common name. The unusual teeth are used to slice open bird and reptile eggs as they are being swallowed.

The newly-described species is quite beautiful, being rusty-red in color and bearing black-bordered white rings (please see article).

Yellow Dyer Rain Frog, Diasporus citrinobapheus

This tiny (0.8 inch), brightly-colored frog delivered a big surprise – the first person to collect one came away with yellow-dyed hands! So far, chemical tests of the dye have revealed no toxins, but frog secretions are very complex, so I’m keeping an eye out for further information.

In common with related species, the Yellow Dyer Rain Frog has no tadpole stage, and is native to montane rainforests in western Panama.

Iridescent Cambodian Skink, Lygosoma veunsaiensis

The skin of this newfound skink flashes a rainbow of colors when illuminated by sunlight. But one must look long and hard to see this creature in the sun (or at all!), as it is highly-adapted to life below ground. Lygosoma’s legs are unusually short, and the tail is twice the length of the body (please see photo). Herpetologists consider its discovery to be a stroke of good luck…related species are so secretive that that most are known from but a few specimens.

The skink is a rainforest dweller, and was found in the Veun Sai-Siem Pang Conservation Area, home also to a newly-described gibbon and bat.

Chocoan Blunt-Headed Vine Snake, Imantodes chocoensis

As can be seen from the accompanying photo, snakes in the genus Imantodes have huge eyes bulging from heads that seem too large for their pencil-thin necks. But their odd structure suits them well as arboreal, nocturnal hunters of frogs and lizards. Armed with excellent vision, they move by literally flinging themselves through the bushes, and can lash out at prey with blinding speed while anchored to a branch.

The group’s newest member was discovered in northeastern Ecuador. In common with related species, it is rear-fanged and clad in cream, copper, brown, and black. Herpetologists are puzzled at its lack of a loreal scale, which is present in all other Colubrid snakes.

Other Recently-Discovered Amphibians and Reptiles

A number of other fascinating creatures made herp headlines in the recent past. Among the most surprising have been arboreal tadpoles that eat bark, a fanged frog that ambushes birds, large, colorful monitors, and a new Map Turtle from the USA.

Many, many other new reptiles and amphibians have been described in recent years…please let me know your favorites by posting below.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Round Island Boa Reintroduction – Back in Wild after a 150-Year Absence

Frank Indiviglio — Wed, 12 Dec 2012 15:11:36 +0000

Hello, Frank Indiviglio here. Mauritius, an island nation off the coast of southeast Africa, is best known to naturalists as the site of the Dodo Bird’s extinction (Mauritius also is, in a sense, the reason I was hired by the Bronx Zoo and spared life as a lawyer – see article below for the story!). Herp enthusiasts, however, know it as the habitat of several unique reptiles, all of which are now very rare or extinct. But we can delight in some news just released by the Durrell Wildlife Trust - a new population of the Round Island or Keel-scaled Boas, Casarea dussumieri, will soon be established in the wild. This unusual snake disappeared from nearly all of its range in the 1860’s, and its return is the culmination of 40 years’ worth of captive breeding and habitat restoration efforts.

Status and Conservation

The Round Island Boa is now confined to Round Island, a tiny speck of habitat where perhaps 500-1,000 individuals survive. A single wild population and limited number of captives place it at continued risk of extinction. The new population to be established on another Mauritian island (where the snake formerly lived) is a vital step towards ensuring the species’ survival.

The Durrell Wildlife Trust became the first institution to breed the Round Island Boa, and maintains most of the captive population. Founded by legendary conservationist and author Gerard Durrell, this unique organization focuses on critically endangered animals and plants, especially those overshadowed by pandas, rhinos and other “charismatic mega-vertebrates”. The Trust was the first to breed the Giant Jumping Rat, Lesser Antilles Iguana, Flat-tailed Tortoise and scores of others (please see article below).

The Reintroduction

The island selected for the new Round Island Boa population has been cleared of the introduced black rats, goats and rabbits that previously destroyed the habitat and prey base. The snake’s primary food, the Telfair’s Skink (Leiolopisma telfairi), was released on the island in 2007 and is now well-established. Like other Mauritian reptiles, Telfair’s Skink has been eliminated from much of its range, but survives on Round Island and at the Durrell Wildlife Trust.

The boas to be reintroduced were collected from Round Island, and will first be monitored to assure that they are genetically diverse and disease-free.

Round Island Boa Natural History

Although originally placed in the genus Boa, this species differs so greatly from seemingly-related snakes that is now classified in its own genus and family (Bolyeridae). The family’s only other member, the Round Island Burrowing Boa (Bolyeria multacarinata), has not been seen since 1975 and is presumed extinct.

The Round Island Boa is oviparous, and changes in color from bright orange to grayish-brown as it matures. There are some indications that females remain with their eggs for a time. Unique scalation lends the alternative common name of Keel-scaled Boa. Juveniles and some adults (especially females) appear to be largely arboreal.

The Round Island Boa’s preferred habitat – forest and palm-dotted savannah – has been largely reduced to brushy scrub by agricultural development, introduced rabbits and goats. Rat predation on young snakes and skinks has contributed to the species’ drastic decline.

What’s Next?

The reintroduced population will be closely monitored by Durrell Wildlife Trust staffers and other conservation organizations. In addition to establishing a new population, the project may serve as a template for future herp recovery efforts. I’ll post updates as they become available.

There are many other success stories, as well as failures. Please post your own thoughts and examples below so that I can share them with readers and researchers. Thanks.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

World’s Largest Snake – Finding and Keeping a Giant Reticulated Python

Frank Indiviglio — Wed, 21 Nov 2012 16:35:04 +0000

Hello, Frank Indiviglio here. While working at the Bronx Zoo, I had the once-in-a lifetime opportunity of helping to import and care for one of the largest snakes in captivity. While “largest snake” debates are ongoing, the massive Reticulated Python I came to know was awe-inspiring by any standard. Dubbed “Samantha”, she was captured as an adult in Borneo, and eventually reached 26 feet in length and 275 pounds in weight. The story of how she arrived in the USA involves a cash reward established by Theodore Roosevelt, the leather trade, animal dealers and other twists and turns.

Wanted: 30 Foot-Long-Snake

In 1910, Theodore Roosevelt, long involved with the Bronx Zoo, offered a reward to the first person who presented a snake of 30 feet in length; in time the reward grew to $50,000. In 1992, I and other Bronx Zoo staff heard rumors that a giant Reticulated Python that had been captured in Borneo. We did not get overly-excited… being well-seasoned, I automatically deducted 25-50% from the size of any “biggest snake-turtle-croc” stories that came my way. But then grainy photos arrived by mail, and the snake depicted was, if not the largest I’d seen, impressive. Whether by design or bad luck, the photos did not allow us to accurately gauge the animal’s length.

In those pre-internet days, it was difficult to correspond with the leather company that owned the snake, which was confined in a railroad car near Samarinda, Borneo. Then as now, importing large animals was fraught with difficulties. Therefore, we enlisted the help of a local leather company with ties in the region and a trusted animal importer.

Meeting a Giant

I was on hand to pick up the snake when she arrived at Kennedy Airport in 1993, but just barely, as there were several cancellations and other problems. I found out about the shipment at the last minute, while at a restaurant. The ensuing trip to Kennedy and the zoo wound up being an interesting first date for my companion, who was not interested in reptiles!

As soon as we hoisted the snake’s crate, we surmised that it did not contain a record-breaker. Our suspicions were confirmed once we stretched Samantha out on the reptile house floor. At a “mere” 21 feet in length and 175 pounds in weight, she was impressive, but far short of what we had been led to believe.

However, after having handled hundreds of large constrictors, I’m able to say that our new arrival was stronger by far than any captive-raised snake of similar size. I’ve also noticed this regarding captive-bred Green Anacondas, when compared to those I’ve caught in the field. As in other species, her muscle tone was also noticeably different than that of her more sedentary relatives.

Wrestling With a Giant (and losing!)

In the wrestling match that broke out once we unpacked Samantha, I wound up in the weighing crate with her. She pushed outward and pinned me against the crate’s side. I know what broken ribs feel like, and mine were just about to crack when my co-workers managed to pull her away from me. Only a few seconds had elapsed, and she was pushing out, not constricting (when she could have exerted far more pressure), but there was no doubt that I was grossly over-matched!

Human-Python Interactions

It was difficult to obtain background information on Samantha…a great disappointment given her size and the fact that she was captured near a village. She was well known by local people, and reportedly used a cave as her main shelter. When Samantha began raiding chicken coops, she was easy to locate. Unfortunately, the actual details of her capture were never revealed.

Reticulated Pythons often adapt well to human presence, and occur even within Bangkok and Singapore, where dogs, rats, cats and livestock form part of their diets. Visiting Singapore Zoo keepers once told me that they lost an adult Cape Hunting Dog to a free-ranging Retic. I recently came across a fascinating article which revealed that 26% of the Philippine Agta men in one region have been attacked by Reticulated Pythons, with 6 deaths resulting. Please see this article for details.

Giant Snake Diets

Samantha proved quite calm as compared to other adult, wild-caught Retics I’ve worked with. Her diet was comprised of 25-30 pound pigs, one of which she consumed each 4-6 weeks. She was certainly capable of taking larger meals, but remained in good health on this feeding regime. At her death in November of 2002, Samantha measured 26 feet in length and tipped the scales at 275 pounds.

The largest snake meal I’ve witnessed was a 60 pound White-Tailed Deer taken by a wild Green Anaconda in Venezuela. I’ve observed and read about many others…please see this article, and post your own experiences below.

Other Giants

The internet is stocked with claims of giant snake sightings, but many border on the ridiculous…and cross that border! However, there are a few legitimate giants in zoos and private collections, including several that are well known by “first name” to snake fans – “Fluffy” and “Marcy” are especially popular.

Clifford Pope’s 1961 classic, The Giant Snakes, is a great resource for snake enthusiasts. His photo of the massive “Colossus” inspired many herpetologists of my generation.

What’s Next?

The Bronx Zoo’s $50,000 reward has been withdrawn, but I like to think that a 30-foot-long Anaconda or Retic is lurking somewhere even as I write these words. Please let me know your thoughts on this prospect, and I’d love to hear any stories, rumors or experiences you may have.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio