World’s largest rattlesnakes are dying off, but Columbia’s zoo is trying to save them – via Herp Digest

By Noah Feit, 12/30/19, The State, South Carolina

Go to https://bit.ly/2SIWKMG, home page for various videos and photos.

Such as a video of a rattlesnake swimming in the Florida Keys.

Ted Wilson, a captain with the Islamorada Fishing Guide, came across a five-foot Eastern diamondback rattlesnake swimming in the waters near the Florida Keys. The Eastern diamondback is the heaviest though not the longest venomous snake in the Ame by McClatchy

Ted Wilson, a captain with the Islamorada Fishing Guide, came across a five-foot Eastern diamondback rattlesnake swimming in the waters near the Florida Keys. The Eastern diamondback is the heaviest though not the longest venomous snake in the Ame by McClatchy

The world’s largest rattlesnakes can be found in South Carolina, but the eastern diamondback’s population is declining

While this might seem like good news to people afraid of snakes, officials at Riverbanks Zoo disagree.

In fact the Columbia zoo is teaming up with the South Carolina Department of Natural Resources to help stave off the trend and better support remaining eastern diamondback rattlesnakes.

The zoo said it is collaborating with DNR to conduct research on diamondback rattlesnake populations in South Carolina.

Once fairly common, populations of eastern diamondback rattlesnakes have declined dramatically. 

Riverbanks is helping the South Carolina Department of Natural Resources conduct research on diamondback populations in this state. The goal is to attempt to learn enough about the biology and natural history of these snakes to allow us to manage the remaining populations, and prevent us from losing a part of our natural heritage, and a potentially important component of the long-leaf pine ecosystem.

The goal of the study is to learn about the biology and natural history of the snakes, according to the zoo. That would allow researchers to better manage the remaining populations, and prevent eastern diamondbacks from dwindling to the point of extinction, zoo officials said.

While the population is dwindling, the rattlesnakes are in the category of “Least Concern,” on the International Union for Conservation of Nature’s Red List for threatened species.

Still, the zoo contends the declining population is a threat to “our natural heritage, and a potentially important component of the long-leaf pine ecosystem.”

The snakes are valuable to humans because they are natural exterminators that preys on household pests, the Florida Museum reported. Their prey includes rats, mice, rabbits, squirrels and birds, according to the Smithsonian’s National Zoo & Conservation Biology Institute.

The snakes are threatened by indiscriminate killing in rattlesnake roundups, widespread loss of habitat from development, and hunting,” according to National Geographic. Agriculture and changes in forestry practices have also been a factor in the population decline, according to the zoo.

The eastern diamondback is found in the Southeast, from North Carolina to south Florida, according to the International Union for Conservation of Nature. In South Carolina, the rattlesnakes are most commonly located from the eastern Midlands to the coast, including the Lowcountry and Grand Strand regions, the organization said.

The snake’s average length is between 3 to 6 feet, but some grow as large as 8 feet, according to the Smithsonian.

The rattlesnake can strike as far as two-thirds of its body length, and it “tends to release a lot of venom with each bite, making it a very deadly snake,” the Smithsonian said.

The bites are “extremely painful and can be fatal to humans,” according to National Geographic.

According to the University of Florida’s Department of Wildlife Ecology & Conservation, the odds of dying from a snake bite in the U.S. are 1-in-50 million, which is about five or six deaths a year. More people die on an average annual basis from spider bites; dog attacks; hornet, wasp or bee stings; and lightning strikes than snake bites, the university said.

In spite of those statistics, at least two Southerners died after snake bites in May this year.

Oliver “Chum” Baker was an Alabama man who died days after he was bitten by a snake over Memorial Day weekend, The State reported. The 52-year-old was unconscious minutes after he was bitten by a copperhead, according to The State.

Georgia resident Priscilla Meridith died in June, weeks after a Timber rattlesnake bit the 62-year-old as she attempted to sit down in a garden, The State reported.

In 2016, Columbia-area conservationist Wayne M. Grooms died after suffering a rattlesnake bite at a Clarendon County wildlife preserve, according to The State. Grooms died within 15 minutes of the snake bite at Santee National Wildlife Refuge.

While there is mixed reaction to the snakes, feedback on Riverbanks’ posts have been supportive of the effort.

“Keep up the great work, Riverbanks! Despite not being a fan of snakes, I completely understand their importance to the environment and appreciate what you are doing to help them,” one comment said.

Another person said “Thanks, Riverbanks, for all you do to keep these handsome guys in our lives!”

Eastern diamondbacks are on display at the zoo’s Aquarium Reptile Complex. Other snakes housed there include king cobras and green mambas.

Video- Venomous or harmless? How to tell the difference between Carolina snakes

The snakes are coming out for the spring season in the Carolinas. Watch how to tell the difference between a deadly cottonmouth snake and a nonvenomous rat snake in this video.

Scientists warn bloodsucking worms found in Florida rattlesnakes may spread – via Herp Digest

 DELAND, Fla. — 4/18/19 WESH2

A biology professor at Stetson University has discovered bloodsucking worms inside three dead rattlesnakes and there is concern the worms could spread to the rest of the country in a matter of years.

Dr. Terence Farrell said that while he was examining a dead rattlesnake, live, parasitic worms began crawling out of its mouth. He described the situation as “pretty alarming.”

The worms have been found in pythons in South Florida – but now that they are in Central Florida there are increased worries for the rest of the country.

The DNA sequences of the parasites found in the pygmy rattlesnakes were consistent with the parasite species from southeast Asia, which is normally found in Burmese pythons.

Farrell and his team of researchers have found the parasites in Central Florida, which is more than 100 miles away from where the Burmese pythons reside in the southern portion of the state.

“Our research shows that the parasites are moving north rapidly along the peninsula and appear to have some major health effects on pygmy rattlesnakes,” said Farrell.

The major concern is the potential impact on the ecosystem if too many of snakes are killed by the parasite.

“This parasite isn’t just a Florida problem. We have no idea how much of the U.S. this parasite will spread and move into, which may cause it to become a nationwide problem in a few years,” Farrell said.

Potential snake gassing ban killed by Texas Parks and Wildlife – via Herp Digest

By Asher Price - American-Statesman Staff, 10/24/16

Sidestepping recommendations from their staff and outside scientists, Texas Parks and Wildlife commissioners have quietly killed a proposal to ban rattlesnake gassing.

Commission Chairman Dan Friedkin, under pressure from key state lawmakers, removed the item from the agenda of the commission’s November meeting, seemingly ending several years of deliberations about the practice, in which gasoline is pumped or sprayed into caves and crevices to drive snakes from their winter dens for capture.

The seized snakes are then featured in rattlesnake roundups — old-fashioned carnivals in which snakes might be put on display, “milked” for venom or used in daredevil stunts.

The commissioners had long been in a political bind: Their own staffers have said gassing is a threat to snakes and other animals that live in the sinkholes, crevices and underground caverns found in wide swaths of the state. But rural lawmakers who represent towns with the popular rattlesnake festivals tried to stymie any ban.

The collection of snakes by gassing “generates passionate appeals from those on both sides,” said Friedkin, who made the decision in consultation with the department’s top staff. Lacking consensus on the matter or support from lawmakers, “any attempt to move forward with this proposal would be futile.”

Friedkin said he has asked Parks and Wildlife Department staffers to find ways to collect rattlesnakes that do not harm other species and “do not carry the adverse economic impacts that an outright ban could have on communities that thrive on rattlesnake roundups.”

Commercial collection of rattlesnakes takes place in dozens of Texas counties, including Williamson, Burnet and Llano, according to the parks department.

A 2013 petition supported by biologists, zoologists, herpetologists and ecologists from Texas and elsewhere triggered a closer look at the issue by the Parks and Wildlife Department, eventually leading to the ban proposal.

Researchers have shown that exposure to gas can cause short-term impairment or death for snakes, toads and lizards.

The commission “has decided that, at this time, there is insufficient support from legislative oversight or the potentially regulated community for the department to move forward with regulating the use of gasoline to collect rattlesnakes,” John Davis, wildlife diversity program director at the Parks and Wildlife Department, said Monday.

Among the lawmakers who have registered their opposition to a ban is state Sen. Charles Perry, R-Lubbock, who represents Sweetwater, home to the largest roundup, and is chairman of the state Senate Agriculture, Water and Rural Affairs Committee.

“It is not necessary for the state to overreact by prohibiting a common practice that has not been conclusively shown to harm wildlife and habitats in its controlled, targeted use,” Perry and other lawmakers wrote to the Parks and Wildlife Department in 2014.

Perry and state Rep. Susan King, R-Abilene, whose district also includes Sweetwater, wrote legislation in 2015 that made it harder to change state rules through petitions.

Perry’s office said he was unavailable Monday, and King did not return a request for comment.

At least 29 states have banned the use of gas or toxic substances to collect or harass nongame wildlife, including the four states bordering Texas — Arkansas, Louisiana, New Mexico and Oklahoma, according to information from environmentalists who were pushing for a ban.

But in Texas, the wildlife commissioners never appeared keen to take action on the ban proposal. The commission tabled a decision in 2014 after lawmakers weighed in and instead, in an apparent attempt at finding political cover, called for a working group to examine the issue. But the working group provided no cover, unable itself to come to consensus on key issues.

Environmental groups again filed a petition in March to push the agency to ban the practice. And in June, the commission’s vice chairman, Ralph Duggins, suggested that agency staffers return with the proposed ban in November, giving commissioners another opportunity to publish the proposal and take public comment on it.

“I’m deeply disappointed that the commission once again caved to pressure from rattlesnake hunters,” said Collette Adkins, a biologist and senior attorney at the nonprofit Center for Biological Diversity.

Rattlesnakes have reduced their repertoire of venoms-Reptiles’ common ancestor possessed greater variety of toxic proteins – via Herp Digest

Science News by Laurel Hamers 9/15/16

Modern rattlesnakes have pared down their weaponry stockpile from their ancestor’s massive arsenal. Today’s rattlers have irreversibly lost entire toxin-producing genes over the course of evolution, narrowing the range of toxins in their venom, scientists report September 15 in Current Biology.

“After going through all the work of evolving powerful toxins, over time, some snakes have dispensed with them,” says study coauthor Sean B. Carroll, an investigator with the Howard Hughes Medical Institute who is at the University of Wisconsin–Madison. These modern rattlesnakes produce smaller sets of toxins that might be more specialized to their prey.

Carroll, an evolutionary biologist, and his colleagues focused on a family of enzymes called phospholipase A2, or PLA2. Genes in the PLA2 family are one of the main sources of toxic proteins in the deadly cocktail of rattlesnake venom. This set of genes can be shuffled around, added to and deleted from to yield different collections of toxins.

Data from the genome — the complete catalog of an organism’s genetic material — can reveal how those genetic gymnastics have played out over time. Carroll’s team looked at the relevant genome regions in three modern rattlesnake species (western diamondback, eastern diamondback and Mojave) and also measured molecules that help turn genetic instructions into proteins. That showed not just how the genes were arranged, but which genes the snakes were actually using. Then, the scientists blended that data with genetic information about other closely related rattlesnakes to construct a potential evolutionary story for the loss of PLA2 genes in one group of snakes.

The most recent common ancestor of this group probably had a large suite of PLA2 genes 22 million years ago, the scientists found. That collection of genes, which probably came about through many gene duplications, coded for toxins affecting the brain, blood and muscles of the snake’s prey. But 4 million to 7 million years ago, some rattlesnake species independently dropped different combinations of those genes to get smaller and more specialized sets of venom toxins. For instance, three closely related rattlesnake species in the group lost the genes that made their venom neurotoxic.

“The surprise is [the genes’] wholesale loss at two levels: complete disappearance from the venom and complete disappearance from the genome,” Carroll says. In other words, some of the genes are still lurking in the genome but aren’t turned on. The proteins those genes produce don’t show up in the venom in modern snakes. But other genes have left the genome entirely — a more dramatic strategy than simple changes in gene regulation.

Environmental shifts might have encouraged this offloading of evolutionary baggage, Carroll says. If a certain snake species’ main food source stopped responding to a neurotoxin, the snake would waste energy producing a protein that didn’t do anything helpful.

Plus, a rattlesnake doesn’t just invest in producing venom. It also needs to produce antibodies and other proteins to protect itself from its own poison, says Todd Castoe, an evolutionary biologist at the University of Texas at Arlington who wasn’t involved in the study. As a snake’s weapon becomes more complex, its shield does too — and that protection can use up resources.

Researchers also found that venom genes might not be consistent even within a single species of rattlesnake, perhaps because snakes in different areas specialize in different prey. One western diamondback rattlesnake that Carroll’s team sampled had unexpected extra genes that the other western diamondbacks didn’t have. His lab is currently looking into these within-species differences in venom composition to see how dynamic the PLA2 genome region still is today.

As for the ancestral rattlesnake, it’s impossible to say exactly how powerful the now-extinct reptile’s venom was, Carroll says. But the wider variety of enzymes this rattlesnake could hypothetically produce would have given it more flexibility to adapt its poison to environmental curveballs — an ability that Castoe describes as “the pinnacle of nastiness.”

Editor's note: Sean B. Carroll is on the board of trustees of Society for Science & the Public, which publishes Science News.

Citations

N. Dowell et al. The deep origin and recent loss of venom toxin genes in rattlesnakes. Current Biology. Published online September 15, 2016. doi:10.1016/j.cub/2016.07.038.

Further Reading

T.H. Saey. Evolution of venom, binge eating seen in snake DNA. Science News, Vol. 185, January 11, 2014, p. 7.

L. Sanders. Venom hunters. Science News. Vol. 176, August 15, 2009, p. 16.