Free-ranging reptiles representing dozens of species from around the world are detected in the United States in any given year, usually as a result of escape or illegal release. Fortunately, many of these individuals fail to establish reproductive populations, but all non-native species can potentially pose risks when introduced.
Florida is a major transportation hub and has a climate that’s suitable for many invasive species. As a result, the state has the world’s largest number of established, non-indigenous reptile and amphibian species (3 frogs, 4 turtles, 1 crocodilian, 43 lizards, and 5 snakes). Of the vast number of lizard species, one group of specific concern are tegu lizards because of the threat posed to native fauna. Two species of tegus are now established in Florida - Salvator merianae (Argentine black and white tegu) and Tupinambis teguixin (gold tegu) – and a third has been recorded here— S. rufescens (red tegu). Georgia is the only other state with a confirmed population of Black and white tegus lizards. Tegus have been removed from several counties in Florida and Georgia, and most recently in South Carolina and Alabama, but large portions of the U.S. contain suitable habitat and conditions for tegu lizards.
Green iguanas (Iguana iguana) are another invasive lizard of concern with populations established in Hawaii, Texas, Puerto Rico, and the U.S. Virgin Islands. Green iguanas are known to eat a variety of native plants including plants that are important for endangered species.
Any animal can be problematic when released in places where it is not native. The safest policy is to find an appropriate home for any animal that is no longer wanted because disposal or release in the wild can do great environmental harm.
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Are invasive snakes dangerous?
Free-ranging snakes representing dozens of species from around the world are discovered in the United States in any given year, usually as a result of escapees or releases from the pet trade, but most of these don't appear to have established a reproductive population. Any animal can be problematic when released in places where it is not native. For example, the brown tree snake was introduced to...
Can invasive pythons be eradicated?
The odds of eradicating an introduced population of reptiles once it has spread across a large area are very low, pointing to the importance of prevention, early detection and rapid response. And with the Burmese python now distributed across more than a thousand square miles of southern Florida, including all of Everglades National Park and areas to the north such as Big Cypress National Preserve...
What is an invasive species and why are they a problem?
An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health. A few well-known examples include the unintentional introduction of the West Nile virus, chestnut blight, the South American...
What is the brown treesnake?
The brown treesnake is native to parts of Indonesia, the Solomon Islands, New Guinea, and Australia. The snake was first sighted on the island of Guam in the 1950s, probably after stowing away on cargo ships coming from New Guinea. In 2020, a population of brown treesnakes was discovered on Cocos Island, a small atoll of the southern shore of Guam, which represents the first instance of brown...
How is the USGS helping to prevent the spread of the brown treesnake?
Preventing the spread of the invasive brown treesnake is paramount. It is much cheaper than intervention once a snake population is established. Without rigorous prevention, control (let alone removal) of an introduced reptile species is extremely difficult. In the case of the brown treesnake, prevention efforts include working to detect stowaway snakes before they leave the island, as well as...
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- FAQ
Are invasive snakes dangerous?
Free-ranging snakes representing dozens of species from around the world are discovered in the United States in any given year, usually as a result of escapees or releases from the pet trade, but most of these don't appear to have established a reproductive population. Any animal can be problematic when released in places where it is not native. For example, the brown tree snake was introduced to...
Can invasive pythons be eradicated?
The odds of eradicating an introduced population of reptiles once it has spread across a large area are very low, pointing to the importance of prevention, early detection and rapid response. And with the Burmese python now distributed across more than a thousand square miles of southern Florida, including all of Everglades National Park and areas to the north such as Big Cypress National Preserve...
What is an invasive species and why are they a problem?
An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health. A few well-known examples include the unintentional introduction of the West Nile virus, chestnut blight, the South American...
What is the brown treesnake?
The brown treesnake is native to parts of Indonesia, the Solomon Islands, New Guinea, and Australia. The snake was first sighted on the island of Guam in the 1950s, probably after stowing away on cargo ships coming from New Guinea. In 2020, a population of brown treesnakes was discovered on Cocos Island, a small atoll of the southern shore of Guam, which represents the first instance of brown...
How is the USGS helping to prevent the spread of the brown treesnake?
Preventing the spread of the invasive brown treesnake is paramount. It is much cheaper than intervention once a snake population is established. Without rigorous prevention, control (let alone removal) of an introduced reptile species is extremely difficult. In the case of the brown treesnake, prevention efforts include working to detect stowaway snakes before they leave the island, as well as...
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