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 the American island of Guam shortly after World War II; it has decimated the native birds, mammals and lizards of Guam, such that only a few small species remain. Guam has now lost 10 of its 12 native forest birds, most of its bats, and about half of its native lizards. Burmese pythons introduction to Florida have been linked to severe mammal declines in Everglades National Park.
None of these snakes pose more than minimal risk to human safety. Human fatalities from non-venomous snakes in the wild are very rare, probably only a few per year worldwide. All known fatalities in the United States are from captive snakes. Predatory attacks by invasive pythons are a possibility, though the rarity of such attacks suggests that they are highly unlikely.
Learn more: USGS Invasive Animals
Related Content
Are there invasive reptiles other than Burmese pythons in the United States that people should be concerned about?
Free-ranging, non-native reptiles representing dozens of species from around the world escape or are illegally released in the United States every year. Many of these species fail to establish reproductive populations, but some are successful. Florida is a major transportation hub and has a climate that’s suitable for many invasive species, so the state has the world’s largest number of...
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...
How have invasive pythons impacted Florida ecosystems?
Non-native Burmese pythons have established a breeding population in South Florida and are one of the most concerning invasive species in Everglades National Park. Pythons compete with native wildlife for food, which includes mammals, birds, and other reptiles. Severe mammal declines in Everglades National Park have been linked to Burmese pythons.The most severe declines in native species have...
Could invasive pythons move into cities?
Boa constrictors and northern African pythons live in or adjacent to the Miami metropolitan area, and in their native ranges various python species and the boa constrictor are often found living in suburban and urban areas. As with alligators, the risk of human attack in urban areas is very low but not absent.
Are large constrictor snakes such as Burmese pythons able to kill people? What is the risk? Would this be in the wild, or in backyards?
Human fatalities from non-venomous snakes are very rare, probably averaging one or two per year worldwide. All known constrictor-snake fatalities in the United States are from captive snakes; these are split between deaths of snake owners who were purposefully interacting with their pet and deaths of small children or infants in homes where a snake was kept captive as a pet. There have been no...
Where are Burmese pythons or other large constrictors distributed in Florida?
The Burmese python is now distributed across more than a thousand square miles of southern Florida, including all of Everglades National Park and areas to the north including Big Cypress National Preserve and Collier-Seminole State Forest. A number of Burmese pythons have been found in the Florida Keys, but there is not yet confirmation of a breeding population in the Keys. A population of boa...
Related Content
- FAQ
Are there invasive reptiles other than Burmese pythons in the United States that people should be concerned about?
Free-ranging, non-native reptiles representing dozens of species from around the world escape or are illegally released in the United States every year. Many of these species fail to establish reproductive populations, but some are successful. Florida is a major transportation hub and has a climate that’s suitable for many invasive species, so the state has the world’s largest number of...
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...
How have invasive pythons impacted Florida ecosystems?
Non-native Burmese pythons have established a breeding population in South Florida and are one of the most concerning invasive species in Everglades National Park. Pythons compete with native wildlife for food, which includes mammals, birds, and other reptiles. Severe mammal declines in Everglades National Park have been linked to Burmese pythons.The most severe declines in native species have...
Could invasive pythons move into cities?
Boa constrictors and northern African pythons live in or adjacent to the Miami metropolitan area, and in their native ranges various python species and the boa constrictor are often found living in suburban and urban areas. As with alligators, the risk of human attack in urban areas is very low but not absent.
Are large constrictor snakes such as Burmese pythons able to kill people? What is the risk? Would this be in the wild, or in backyards?
Human fatalities from non-venomous snakes are very rare, probably averaging one or two per year worldwide. All known constrictor-snake fatalities in the United States are from captive snakes; these are split between deaths of snake owners who were purposefully interacting with their pet and deaths of small children or infants in homes where a snake was kept captive as a pet. There have been no...
Where are Burmese pythons or other large constrictors distributed in Florida?
The Burmese python is now distributed across more than a thousand square miles of southern Florida, including all of Everglades National Park and areas to the north including Big Cypress National Preserve and Collier-Seminole State Forest. A number of Burmese pythons have been found in the Florida Keys, but there is not yet confirmation of a breeding population in the Keys. A population of boa...
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