From giant toads to highly-adaptable hybrid snakes, let’s take a look at 8 of Florida’s
most invasive species: Number 8 Nile Crocodile
Even though they aren’t an established species, the mere idea of Nile crocodiles calling Florida
their home is terrifying.
In the past, several were found in the state’s south but they’d most likely escaped captivity
and weren’t considered evidence of an invasive process.
Even so, Florida officials were given the green light to shoot any Nile crocodiles on
sight, to eliminate any chance they might have of reproducing.
That’s because these creatures are among the most dangerous predators in the animal
kingdom.
They're massive crocodilians with heavily armored skin which are second in size only
to saltwater crocodiles.
There have been reports of some over 16.5 feet in length and 1,650 pounds in weight.
With an extremely powerful bite, and once their jaws grip you it’s almost impossible
to escape.
They can apply high levels of force for an extended period of time, which is useful in
their native environment when they’re drowning large prey.
In Africa, these highly aggressive animals have earned a reputation as man-eaters and
they’re responsible for hundreds of human fatalities every year.
Their fearsome reputation dwarfs that of the American alligator, which would arguably be
inferior to Nile crocodiles should the two ever compete for food.
Number 7 New Guinea Flatworm Much like their name implies, this flatworm
species is native to the island of New Guinea.
They've been observed preying on earthworms, land snails, slugs and other invertebrates.
In Florida, New Guinea flatworms were first observed in Miami-Dade County, in 2012.
Since then, reports have been coming in from over 40 counties.
As an invasive species, the New Guinea flatworm has reduced the Hawaiian tree snail population
in Oahu and is a known land snail predator in Japan.
In Florida, it can consume threatened or endangered snail species.
The flatworm is also a carrier for the rat lungworm parasite, which can be transmitted
to people via ingestion.
However, so far, there haven’t been any confirmed reports of rat lungworm infection
in Florida’s human population.
Number 6 Argentine Black and White Tegu The Argentine Black and White Tegu is a large
lizard, native to South America.
Found in Brazil, northern Argentina, Paraguay and eastern Uruguay.
Reproducing tegu populations are established in Florida, mainly in Miami-Dade and Hillsborough
Counties, but reported sightings have been coming in from other counties as well.
Like other animals on our list, their introduction in the wild was a consequence of the ever-booming
pet trade which takes place in the state.
Tegus can reach almost 4ft in total length and weigh close to 10 pounds.
On average, females lay about 36 eggs each year.
Once hatched, they grow rapidly and can live up to 20 years.
As adults, these creatures have few natural predators.
Tegus are omnivorous lizards that consume insects, fruits, eggs and small animal such
as rodents and reptiles.
They’re a threat to local wildlife due to their habits of preying upon the nests of
other animals, they’re known to eat young gopher tortoises, animals which are considered
threatened.
They also eat agriculturally valuable foods and, according to recent evidence, their population
seems to be expanding.
Number 5 Giant Toad This invasive amphibian secretes a potent
toxin as a defensive mechanism against predators.
The giant toad, also known as the cane toad, can grow to be 6 to 9 inches in length.
First introduced to Florida in the 1930s and 1940s as a means of controlling agricultural
pests.
They breed year-round in standing water, canals, ditches and streams.
Currently, breeding populations are found in central and south Florida.
Giant toads secrete a milky-white toxin from glands which are located behind their ears.
They can sicken and even kill domestic pets and native animals that bite on them.
For people who handle these toads, their secretions may irritate the skin or burn the eyes.
Number 4 Nile Monitor Nile monitors are among the largest lizards
in Africa, reaching over 7ft and weights in excess of 33 pounds.
Monitor lizards have strong legs, muscular bodies and powerful jaws.
Their sharp claws are used for digging, climbing or tearing at their prey.
They’re an invasive species in Florida, with the most concentrated population located
in Cape Coral, in Lee County.
They tend to inhabit water edges and their spread is facilitated by South Florida’s
extensive canal system.
Monitor lizards negatively impact the areas they inhabit, due to a combination of factors.
They have a generalist diet, a high reproduction rate and travel both in fresh and saltwater.
In Africa, they’re known to raid crocodile nests, eat eggs and prey on small crocodiles.
This can affect Florida’s indigenous crocodiles, such as the American alligator and the American
crocodile.
In Cape Coral the lizards have been connected to the disappearances of livestock and domestic
pets.
Since their diet is so broad, it means that federally protected species, such as sea turtles,
gopher tortoises or wading birds, are also in danger.
Number 3 Lionfish The first reports of invasive lionfish came
in 1985, off Florida’s Atlantic Coast, near Dania Beach.
The exact circumstances of their introduction aren’t clear but it’s suspected that they
were discarded from aquariums.
As of 2010, they began turning up in areas were no lionfish had previously been recorded,
such as the northern Gulf of New Mexico.
As a predatory reef fish, this creature can reduce important native fish populations,
such as herbivorous species that keep the algae levels in check.
In fact, the lionfish is considered the greatest threat to coral reefs in the region and could
be reducing Atlantic reef diversity by up to 80%.
Lionfish, which are usually 12 to 15 inches in length, tend to be larger in areas where
they aren’t indigenous, exceeding 18 inches.
They also have venomous spines on their fins which can cause you painful injuries if the
fish aren’t handled properly.
Number 2 Gambian Pouched Rat With lengths of up to 3 feet from head to
tail, the Gambian pouched rat is one of the largest rat species in the world and it enjoys
a wide distribution in Sub-Saharan Africa.
The species’ common name was inspired by its habit of storing food in its cheek pouches.
In Florida, the rats were introduced through the pet trade and some were bred in captivity
on Grassy Keys.
Then, at some point, several rats either escaped or were released on purpose, and established
a breeding population in the area.
As an invasive species the Gambian pouched rat is of high concern.
Females can produce litters up to five times over the course of nine months and each litter
features an average of four young.
So far, the rats have been contained to Grassy Keys but, should they reach mainland, they
might pose a threat to the agricultural industry in the south of Florida.
Native rat species, such as the Key Largo wood rat, the silver rice rat or the cotton
rat, might also suffer because the invasive species is larger than them and may out-compete
them for food.
There are also several health concerns.
The African rodent was responsible for the 2003 outbreak of monkeypox in the US.
All of the 71 reported monkeypox cases were traced back to Gambian pouch rats, imported
from Ghana by an exotic pet distributor.
The suspicion is that the rats, which are known carriers, had spread it to prairie dogs
which were then purchased as pets.
The infectious disease has a 10% risk of death and, in the aftermath of the outbreak, the
importation of Gambian pouched rats was banned.
Fortunately, no deaths were recorded but patients did experience fever, muscle aches, headaches
and rashes.
Number 1 Hybrid Snakes Burmese pythons are giant constrictor snakes
that can reach over 15 feet in length.
Because of their size, they face few predators, with the exceptions of humans and alligators.
Over the course of a decade, starting from 2001, scientists have examined the tissue
from 400 invasive Burmese pythons, captured in Florida’s Everglades.
It’s worth mentioning that pythons have been breeding in the area ever since the 1980s,
with a devastating impact on the local small-mammal population.
When they were analyzed from a genetic perspective, 13 of them were discovered to have been a
cross-breed between the Burmese python and the Indian rock python.
The latter is smaller, faster and arguably more aggressive than the Burmese python and
tends to prefer a higher and drier environment.
The interbreeding most likely took place before the snakes became established in South Florida.
The discovery is worrisome because the hybrid species displays signs of increased adaptability,
both in dry and wet habitats.
This is due to something called ‘hybrid vigor’ which occurs when the best traits
of the interbreeding species have been passed on to their offspring.
In this case, it might mean that these invasive pythons will exhibit a broader and faster
distribution.
This doesn’t bode well for Florida’s wildlife officials, who’ve already faced difficulties
in eliminating the snakes from the Everglades region.
There are close to 150,000 pythons wreaking havoc on native species, such as bobcats,
foxes, raccoons and rabbits.
In this context, the threat of a super-adaptable python spreading through Florida is most definitely
cause for concern.
Thanks for watching!
Which invasive species do you think has the greatest impact on Florida?
Let us know in the comment section below!