Texas is a massive state, second only in size to Alaska. The state’s warm climate and many different climate zones provide a home for a variety of wildlife, many of which aren’t really supposed to be there. These are called invasive species, which means they aren’t native to the state and arrived in an unnatural way. In this article we’re going to look at some of the most commonly known invasive species in Texas.
We’ll get right to it, but first let’s more clearly define exactly what constitutes an exotic species.
What is an invasive species?
An invasive species is any organism that has established a breeding population in an environment where it isn’t native.
12 different invasive species in Texas
There are hundreds of invasive species in Texas, but here are the twelve most interesting.
1. Red Imported Fire Ants
Scientific name: Solenopsis invicta
If you have ever made the mistake of stepping onto a fire ant hill, you likely know one of the major impacts of fire ants. If you haven’t, let’s just say it hurts, really bad. Their stingers carry a neurotoxic venom that can kill small animals and other insects, but also can cause fever and other issues in humans if you are sensitive to their bites.
These ants have no known predators in Texas and they are very aggressive, attacking any animal that dares walk across their mound home. In addition to their bites, they can also cause devastation to lawns and crop fields with their extensive mound nests.
2. Mediterranean House Geckos
Scientific name: Hemidactylus turcicus
On the opposite end of the spectrum is the Mediterranean house gecko. These small geckos are invasive, but as far as anyone can tell, they have very little impact on the native environment. They mostly live and reproduce in cities around homes and other buildings.
They feed on moths, roaches, and other insects. While many species on this list are displacing natives or eating natives, the house gecko seems to just be filling a niche that was left open.
Scientific name: Myocastor coypus
These cute beaver-like rodents have established themselves in over 20 states! With fast maturation and quick reproduction rates, they are a major threat to the environments they have found themselves in.
Nutria were brought to the US in the late 1800s from South America to be used in the fur trade. When the farms raising them were unsuccessful, many were released into the wild or sold for jobs they weren’t suited to.
Texas was one of several states that brought in nutria to control problematic vegetation and control weeds. Unfortunately, that plan didn’t quite pan out and the Nutria went after the sugar cane and other crops instead, causing an estimated 1 million dollars in damage annually.
Scientific name: Sus scrofa
Another widely distributed invasive is the feral pig. Originally introduced by Spanish explorers, they are now established in 29 states. Breeding year-round in Texas, they reproduce quickly and can cause significant damage to native flora and crops.
With very few natural predators in Texas, the main method of controlling feral pigs is hunting. If you encounter a feral pig in the wild, it’s important you maintain a safe distance and try not to make it feel threatened. Feral pigs can be very dangerous if provoked, especially during the breeding season and when sows have litters of piglets.
5. Cuban Tree Frogs
Scientific name: Osteopilus septentrionalis
The Cuban tree frog is both damaging to native wildlife and a danger to humans and pets. With high reproductive rates and a voracious appetite, Cuban tree frogs both outcompete and eat native frog species in addition to other small animals and insects.
In addition to their aggressive feeding behaviors, they also secrete a mild toxin from their skin that can irritate the skin and eyes of humans. Be sure to keep these frogs away from your cats and dogs as eating them can also cause nausea and vomiting.
If you find a Cuban tree frog and you are sure of the species, it’s recommended you humanely euthanize the animal. This can be done by applying around an inch of benzocaine ointment to the animal’s back. Once the frog is unconscious, you then place it in your freezer for 3 days. This is the kindest method of euthanasia for frogs and will help keep your native frog population safe.
6. Brown Tree Snake
Scientific name: Boiga irregularis
Originally from Australia, these snakes have been introduced to several states, but to know the damage they are capable of, we must look at their effect on Guam. There, they are thought to be responsible for the extinction of several bird and lizard species and the decline of the remaining species. This has also caused a trickle-down effect that is affecting native plant pollination as well.
7. European Starling
Scientific name: Sternum vulgaris
These birds were introduced in the late 1800s as part of a project meant to introduce the birds of Shakespeare to the US. What started out as a rather innocent project has led to a widespread environmental issue.
The starling’s behavior of taking over the nests of other birds has led to a decline in many native species. These birds reproduce quickly and are very opportunistic feeders, frequently begging for food in parking lots across the US.
8. Eurasian Collared Dove
Scientific name: Streptopelia decaocto
These birds are known to be monogamous and can have 3 or more clutches of eggs a year. This prolific breeding has played a factor in their spread across the US and the northern reaches of Texas.
Though there aren’t any obvious negative effects on the ecosystem caused by the doves, it is believed they may defend their preferred feeding and nesting spots from native doves.
They are also a potential host for Trichimonas gallinae which is potentially deadly for native dove populations.
Scientific name: Pterois volitans
It’s unknown how the lionfish ended up in coastal waters off of Florida and Texas. One theory is that a large fish tank was destroyed during Hurricane Andrew and this destruction washed the fish in the tank into the Gulf. While it’s possible this did happen, it’s unlikely aquariums are the only source of the fish in our waters.
The danger of lionfish is their opportunistic and aggressive feeding behaviors and their lack of natural predators due to their venomous spines. Lionfish will feed on any fish and crustaceans they can catch, and even nibble on corals. With female lionfish able to produce close to 2 million eggs a year, this is a problem that could get out of hand quickly.
Recently there has been a movement to promote lionfish as a popular food item. This has led to more fishermen spearing the fish for food and cutting down on the population.
10. European Eel
Scientific name: Anguilla anguilla
The main threat European Eels pose to native species is actually not a direct threat at all. As a natural host for a nematode known as Anguillicola crassus these eels can transmit parasites to our native eels quite easily. While the European eel seems to have some built-in immunity to these nematodes, our eels have none and are very susceptible to the damage caused by them.
Other than their parasitic friends, European eels are actually quite interesting, with the oldest known specimen living to be 85 years of age. They go through several stages of life, with some being dependent on a change in salinity from freshwater to saltwater and back again.
11. Giant African Land Snail
Scientific name: Lissachatina fulica
Thankfully, these voracious giants aren’t quite established as invasive species in Texas, but they have been found in Texas and they do have the potential to be devastating.
If you have ever had snails in your garden, it’s likely you know the damage they can cause in just a short period of time. Now picture those snails are 10-15 times larger and willing to eat bark and stucco if other plants aren’t available. These mollusks are also potential carriers of a parasite that can transmit meningitis to humans. This is one invasive species I’m very glad hasn’t found its foothold!
Scientific name: Felis cactus
If you are a cat lover like me, you likely aren’t happy seeing cats on this list, but unfortunately, feral cats cause an overwhelming amount of ecological damage every year. Cats are one of the few animals that will catch and kill prey for fun, catching native birds, lizards, frogs, snakes, rodents, and even butterflies. If you have cats, please do nature a favor and keep them inside or keep them in an enclosed area while outside.