Tegu lizards threaten native species around Riverview- Tampa, Florida – via Herp Digest

The invasive lizards, which can reach five feet in length, are well established in east Hillsborough.

TAMPA — The Argentine black and white tegu lizard isn’t something you’re likely to forget if you see one in your yard, not only because of its vivid pattern but also because of its size; a full-grown tegu can stretch five feet from the tip of its snout to the tip of its tail.

The invasive species is well established in two Florida locations, the Homestead area of South Florida and the Riverview area of east Hillsborough County.

Though it has a mean bite if aggravated or cornered, it’s not venomous. But it joins a host of exotic reptiles, especially the Everglades’ Burmese pythons, that are wreaking havoc on the Florida ecosystem, said Todd Campbell, a University of Tampa biologist and expert on both the tegu and the monitor lizard, a three- to seven-foot long carnivore that has overrun the city of Cape Coral.

“We’ve got pythons, over 50 species of lizards, a couple of frogs — the Cuban tree frog, the greenhouse frog and the cane toad — so in terms of reptiles and amphibians, Florida is the most invaded area on earth that I know of,’’ Campbell said.

The tegu is an omnivore. It eats fruits, vegetables, dog and cat food, insects and small animals. But because it especially loves eggs, it’s devastating to turtles, alligators and ground-nesting birds. Of course, it will happily eat the live babies, too.

The tegus work the environment almost like a bear, Campbell said. “Think about a bear. They eat nuts and berries, they forage for food, and then if they’ve got a chance to get a mammal, to kill something, they will. They’re opportunistic that way.’’

The state’s biggest population is in extreme South Florida. “They are completely infested in there. They’ve caught hundreds of these animals,’’ Campbell said.

It’s harder to get a sense of how many are foraging around east Hillsborough County. The Florida Fish and Wildlife Conservation Commission has compiled reports of 307 tegu sightings, according to a spokeswoman, and have trapped and removed 128, but it has no estimate of how many are really out there. Captured lizards are euthanized.

Campbell thinks the Riverview population numbers in the thousands. He suspects they were well established there by the year 2000.

"It’s proven difficult to sort of manage them, figure out where we’re going to trap, find the little routes where we could trap them,’’ he said.

Researchers figure these invasive animal species get established in Florida after escaping from or being released by a pet owner or pet dealer. A sudden explosion of an invasive species population in an area indicates that a bunch were released at once, possibly by a dealer who has gone bankrupt and decided to set the inventory free, Campbell said.

In 2007, Campbell called on scientists to make a full-bore effort to save the state from invasive amphibians and reptiles.

  

"Amphibian and reptile introductions are reaching epidemic proportions in Florida, largely due to irresponsible behavior by pet owners and the pet industry, but also due to ineffective preventive policies and actions,'' he stated in a paper delivered at a symposium on managing vertebrate invasive species.

 "Prevention of additional amphibian and reptile introductions in Florida will require a comprehensive approach involving legal restrictions of certain problematic species, a massive public education effort, and a well-funded and staffed Early Detection and Rapid Response (EDRR) program.’'

Campbell said he worries that if the invasive species aren’t eradicated, it could lead to eventually to what he calls “biotic homogenization.’’

He can imagine it happening around the world. "As we transport critters all around the planet, and those critters we transport cause the extinction of critters in those new locations, we’re just going to end up with one big globe of sameness. That’s a little dramatic, but you could make a logical leap to that end point: we’re going to end up with a couple of hundred species that are very, very dominant everywhere on earth.’’

To get a better grasp of the threat to the state and develop strategies to fight it, the Florida Fish and Wildlife Conservation Commission has set up a toll-free number for people to call if they see an invasive reptile or amphibian – 1-888-IVE-GOT1 (888-483-4681). From those reports, scientists can determine the size of the problem in a given area.

Department of Biological Sciences helps target invasive species (The Tegu Lizard now in Georgia digging up Gopher Tortoise Eggs) - via Herp Digest

The George-Anne-Georgia Southern University 

by Nathan Woodruff , Aug 26, 2019

Statesboro, GA — Faculty and students at the Georgia Southern University Department of Biological Sciences are helping state and federal agencies target the Tegu lizard, an invasive species in Tattnall and Toombs county. 

An invasive species is one that is not native to a specific location and that has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health. 

Lance McBrayer, Ph.D., professor of General Biology and Herpetology, graduate student Jada Daniels and undergraduates Michael Brennen and Noah Osterhoudt are involved on the project. 

The Tegu lizard has been deemed a threat because they are especially good at hunting and finding eggs, specifically that of the gopher tortoise, which is listed as a vulnerable threatened species, as well as small animals. 

"We are worried about losing our already threatened species and they will go and hunt other small animals as well that we should be concerned about,” Brennen said.

The GS team is using several approaches, including posting flyers on ATV trails, social media outreach, with over 70,000 people reached. The second thing they are doing is using chicken eggs to bait the lizards and use a camera to spot the lizards.

“We’ll bait a trap and leave it closed, so we don’t catch anything but then have a game camera on that trap so if something comes by and smells it or trips the sensor then we realize they are there,” McBrayer said. “We are going to increase our efforts in that kind of trapping.”

The sightings cover about 150 square miles which are confirmed through sightings on the game cameras. Eyewitness reports have also helped pinpoint the lizards’s exact location. Sightings of the Tegu lizard can be reported at the Georgia Invasives website.

The idea among area officials is that this problem was caused by pet releases and perhaps relocations.

“Most of them this far north are pet releases,” McBrayer said. “Someone was probably raising them in outdoor pens, that was the rumor we have, and then they let them all go.”

Reduction or eradication of the Tegu population in Georgia before more damage is done is the ultimate goal of the program.

The lizard is native to Argentina and Brazil, and it has found a home in Georgia because it is on a similar latitude in the Northern Hemisphere that the lizard’s habitat would be in in the Southern Hemisphere.

The warm and loving tegu lizard becomes a genetic resource

The tegu, a South American lizard with its own heating system, has had its genome sequenced to an unprecedented level of quality

Date:  November 27, 2018

Source:  GigaScience

Published today in the open-access journal GigaScience is an article that presents the genome of the tegu lizard, which has mastered a trick that is highly unusual in the reptile world: it can turn on its own heating system.

Most reptiles are not able to control their body temperature like mammals do and instead must rely on its environment, such as available sun and shade, to attain an optimal body temperature. The tegu, Salvator merianae, however, has taken a step towards being full-blown warm-blooded: It can raise its own body temperature by up to 10°C above its surroundings. Another, but more negative, aspect of the tegu is that is an invasive species and poses a serious threat to endangered species. Although it is a native of South American rain forests and savannas, the charismatic nature of the tegu -- and that it can even achieve some level of house training, makes it an extremely charming pet that is much beloved by reptile aficionados. Unfortunately, international trade in exotic pets are one of the primary reasons that species enter new environments where they can become a menace to the native species. Given the tegu's unique biological characteristics and its potential peril to the environment, the availability of an extremely high-quality genome sequence of this large lizard serves as a rich resource for identifying and analyzing the underlying molecular basis of these aspects.

The tegu genome sequence, provided by a team of researchers led by Michael Hiller at the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden (Germany), is of unprecedented quality. To accomplish this the researchers used state-of-the-art technology to read the tegu's DNA and assemble its genome sequence. The newly released genome sequence of S. merianae is more than two billion DNA letters long and contains more than 22,000 genes. It is the most complete assembly of any reptile genome so far and will also aid scientists to study other lizards and snakes.

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Tegu lizards warm up for mating season – via Herp Digest

by Helen Thompspn, 1/22/16, Science News

Despite their cold-blooded reputation, tegu lizards boost their body heat while on the prowl for a mate, biologists report January 22 in Science Advances.

Like other ectotherms, South American tegu lizards (Tupinambis merianae) draw heat from their environment, sunning themselves in spring and summer and hibernating in autumn and winter. Upon waking from their seasonal slumber, the reptiles search for a mate.

Researchers from Canada and Brazil monitored body temperature in a group of captive lizards through these seasonal shifts. At night during mating season, their bodies stayed significantly warmer (by up to 10 degrees Celsius) than the air. The lizards maintained this temperature difference for up to eight days without the help of sunlight.

Researchers saw a steady rise in heart rate and body temperature, suggesting that tegu lizards have an unusual ability to produce and sustain body heat. Though the exact mechanism remains unclear, metabolic changes that come with reproduction could drive up the lizards’ body temperatures, the researcher suspect. The work lends credence to the idea that reproduction played a role in the evolution of warm-bloodedness.

The Everglades has a new villain: omnivorous lizards

Metre-long tegu lizards may be even more damaging to the ecology of the Everglades than giant pythons.

MIAMI—The Argentine tegu lizard doesn’t grow nearly as big as a Burmese python but it may be a greater threat to South Florida’s native animals.

At a maximum size of 1.2 metres, a tegu can’t gobble down a full-grown deer or alligator with its rapier-sharp teeth. But the invasive, black and white reptiles have the potential to cause even more ecological damage than the giant snakes that have drawn international media attention in recent years.

And now, scientists say, it’s too late to eradicate them.

“When we first found out about them in 2008, we thought we had a chance to nip this population in the bud,” said the National Park Service’s Tony Pernas, who co-chairs the Everglades Cooperative Invasive Species Management Area group. “Now we’ve changed from eradication mode to containment mode.”

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