2020 is a year of environmental threats

First we had murder hornets threatening the west coast honeybees. Then zombie cicadas threatened each other. Finally, unknown, unsolicited seeds started showing up in people's mailboxes. 2020 has been a troubling environmental year for everyone and just when we thought we could close it out without another threat, the Argentinian tegu lizard is moving north. This large reptile, native to Argentina and South America is a often kept by reptile lovers. At least, until it grows to over four feet in length with an appetite to match.

The Argentinean tegu lizard is a popular pet

The giant tegu lizard is a beautiful creature. The banded and spotted black and white skin is striking and the lizards make good pets. They are favorites among the reptile-keeping community because they are docile and like human companionship. As crazy as it sounds, they are even intelligent enough to housebreak and walk on a leash. The problem is, a four foot dog-like lizard is difficult to keep in a normal household, so when they outgrow their living space, many of them are simply set loose in warm climates. They have established themselves with a breeding population in south Florida and are now moving north. Tegus have been spotted in Georgia and South Carolina this year and their population explosion is worrying environmentalists.

Tegu lizards are an invasive threat

Tegus are big lizards and are omnivorous. This means they consider just about anything food. The young ones love insects, spiders and other small invertebrates and this isn't so bad. However, as they grow, they develop a liking for protein and fruit. Wild ones also become predatory. Ground-nesting birds are especially vulnerable, as their eggs are considered a treat. This is also true for turtle eggs and other reptiles like the rare American crocodile. Tegus will also hunt small mammals and will see no difference between a rat and your puppy or kitten. They have no natural enemies here, so as long as they like the weather, they set up housekeeping and reproduce. Even the cooler winters further north than south Florida don't faze them. Tegus like to burrow, so they simply dig a hole and wait the winter out underground.

Armadillos are another South American invasive

This reminds me of the armadillo, (another invasive species) that was originally found in South America and Mexico. It has gradually been moving north since the 19th Century and is now found throughout the South and even into the Midwest. People scoffed at the idea that this little anteater relative would move into areas with freezing winters because they weren't supposed to survive temperatures below 28 degrees Fahrenheit. Tell that to the west Kentucky armadillo population. They survive much colder winter temperatures than that here and have been spotted as far north as Nebraska. More than likely, they just burrow down when cold weather hits, like the tegu does. Invasive species are adaptable and that is why they can conform to different climate and environmental situations.

Insect pests that overwinter

Other invasives that have adapted are the Asian ladybeetle and the brown marmorated stink bug. They have hitched rides on container ships and have settled right in here in North America. They search out sheltered spots in cracks and crevices to spend the winter and often find their way indoors. They have no natural predators, except for the vacuum cleaner as we suck them off walls and ceilings. They send out pheromones that attract all of their friends and relatives and soon you have a house full of unwanted insect guests. They are troublesome, have an unpleasant odor and are impossible to get rid of.

giant tegu lizard

Exotic pets are fine until released into the ecosystem

People do not realize what damage owning an exotic pet can have. They think that they will never be the one to contribute to the problem and even if they do release such a pet into the wild, they just think it is only one, so what's the harm? Non-native animals have no natural enemies and given favorable circumstances, the population explodes at a much faster rate than native species. They use resources that our natives need to survive and no predator bothers them. They then have a comfy place to raise their young and expand their range even further. The tegus are doing that right now. And while they haven't increased their northern population enough to be considered an uncontrollable threat, that day is coming.

Early containment is the key to controlling invasives

Just like the murder hornets that the west coast is trying to contain, we should be vigilant for the tegu. News reports show that they have actually found at least one murder hornet nest with a queen, so that means there are probably more. If you spot a tegu, try and grab a picture of it and note the location. Contact your state's Department of Natural Resources and give them all the information you can. Someone will come out and try to capture it. The more of them we can eliminate from the wild, the less chance we have of them over-running our native wildlife. Their ravenous appetites threaten many egg-laying species and small animals, so it is best to get them out of the ecosystem quickly.

Southerners, be on the lookout for tegu lizards and notify the authorities

Invasive species are no joke and the tegus should be taken seriously. They are past the point of controlling them in south Florida. There are too many of them and too many places for them to hide and breed. The best we can hope for is to prevent their march north. People in the southeast states should be on the lookout. Some have even been spotted as roadkill and hitting a four foot lizard with your car will probably give your insurance agent a headache. While they are not aggressive, they will bite if threatened. Their bite isn't poisonous, however it can leave a substantial mark, especially on a child. Every time we bring in a non-native animal or plant into our ecosystem, we run the risk of it escaping and doing irreparable damage to what belongs here. Exotic pets and garden plants are cool, however if they cannot be contained responsibly, we should enjoy them in settings where the experts manage them with care.