The Invasive Species Of The Everglades

The Florida Everglades are home to more than 400 species of animals, ranging from reptiles to mammals. All of these animals, and their surrounding environments, are threatened by invasive species. Invasive species start out as non-native species, which are animals that did not originally live in Florida. The state of Florida has documented over 1170 non-native plant species and over 450 non-native wildlife and fish species. Some of these invasive species are the green iguana, the Cuban tree frog, and the worst one of all, the Burmese python. Almost all non-native species are brought to Florida by humans. The primary way non-native species get into our environment is when the owners of these animals allow them to escape, or release them into the environment. Another main way that non-native species make it to the Everglades is when ships come to Florida. As ships travel, they collect ballast water. This is foreign water and it can contain a variety of foreign species. When the ships dock, they release the ballast water and along with it, the foreign species. Another way non-native species make it to Florida is through packaging materials such as crates. The animals stay inside these crates throughout the journey to Florida, and once the crates are opened, the non-native species are free to roam. An example of a non-native species that was introduced to Florida through packaging materials would be the Cuban tree frog. In 1931 it was introduced through packaging materials and is now considered an invasive species. A non-native species becomes an invasive species when it begins to live in the environment with the native species and has a negative effect on the lifestyle of other animals and plants. Invasive species cause a multitude of problems. In many cases, they will prey on the native species and force them out of their habitat. They are also known for destroying certain habitats. An example would be the green iguana, which is notorious for causing significant economic damage to landscape plants. There many on going efforts to help reduce the number of invasive species in Florida, specifically the Everglades. These efforts range from trappers, who come in and trap the animals and later release them into their natural environment, to awareness groups who make the public aware that they should not release or allow their exotic pets to escape into the environment. Invasive species cause the United States more than $1 billion a year due to the economic loss they cause. Also, 42% of the endangered species in the United States are endangered because of non-native and invasive species (Invasive Species 101, para 1). As shown, invasive species are becoming a huge problem for Florida, specifically the Everglades.

One of the primary invasive species in the Florida Everglades is the Cuban tree frog. The Cuban tree frog is the largest frog in North America. Their size ranges from 4-14 centimeters and their skin is usually bronze, green, or gray (eNature, para. 2). The Cuban tree frog’s native habitats are the Bahamas, the Cayman Islands, and Cuba. They can be distinguished from native frogs by their large toe pads on their feet. The Cuban tree frogs were introduced to Florida in 1931. They were brought here by ships that were carrying packaging materials from their native habitats (most likely Cuba). By the 1970s, Cuban tree frogs were wildly rampant in southern Florida, specifically the Everglades, and this is when the problem began. The Cuban tree frogs are a nocturnal species and spend a majority of their time in trees where they prey on their food which includes insects, mice, snakes, lizards, hatchling birds, native frogs, and occasionally, other Cuban tree frogs. These predators cause numerous problems in the areas that they inhabit; specific problems are home invasion and population impacts on the native species. They primarily live in areas like the neighborhoods where they prey on the local frogs on that area. In fact, many homeowners have commented that they have noticed an increase population of Cuban tree frogs and a decreased population of the native frogs. The Cuban tree frogs also live throughout large areas of the Everglades. When they are in the Everglades, they can cause two main problems for the native frogs. They will either push the native frogs out of their habitats, causing them to find new shelter and food, or, they will just devour the native frogs. Both of these are leading to a rapid decline in the population of native frogs because the native frogs do not have time to reproduce when they are too busy being pushed out or eaten by the Cuban tree frogs.

Another invasive species of the Everglades is the Nile Monitor. The Nile Monitor is a large lizard that can grow up to 7.5 feet and their weight can exceed 25 pounds. They are characterized by their heavy body, long-forked tongues, and long tails. Their native home is throughout central and southern Africa, including Sudan and a small portion of central Egypt (USGS, 2007, para. 1-4). The Nile Monitors were brought to America to be used as pets, but because of their aggressive nature and large size that they grow to, owners end up releasing them into the environment, not realizing what they are doing. Once they were released they spread all through southern Florida, specifically the Everglades. Once there, they began reproducing, and the population spread as they began to become a dominant creature, devouring whatever they pleased. The Nile Monitor is almost always diurnal and they are a carnivore. Their diet consists of fruit, invertebrates, mammals, birds, fish, carrion, and eggs (New World Encyclopedia, 2008). These large lizards are very aggressive and have a powerful bite, thus, most people that own them eventually release them into the environment, and this is where the problem begins. Nile Monitors that live in the Everglades use American Crocodile and American Alligator eggs as one of their primary food sources. The Nile Monitors raid the nests of the American Alligator and American Crocodile and devour their eggs. By eating these eggs, they are reducing the number of crocodiles and alligators born each year. This is having a large impact on the population of American Alligators and American Crocodiles. The Nile Monitors also use burrowing owls and gopher tortoises, both of which are a legally protected species, as another primary food supply, and this, like that of the American Alligator and American Crocodile, is having a large impact on the population of these two species. Along with creating a large problem with the population of other species, the Nile Monitor harbors exotic parasites that could possibly have an impact on indigenous vertebrates and humans. Overall, the Nile Monitor is a very aggressive lizard that is slowly reducing the populations of American Alligators, American Crocodiles, Burrowing Owls, and Gopher Tortoises.

Lastly, but most certainly not least, is the Burmese Python. The Burmese python is native throughout Southeast Asia including Burma, Thailand, Vietnam, southern China, and Indonesia (Anapsid, 2009, para. 4). They are one of the largest snakes in the world, growing up to 20 feet in length and up to 200 pounds. The Burmese Python slithered into the Florida Everglades around the late 1990s. The Burmese Python in the Everglades is primarily fueled by private owners. Each year, Miami receives 12,000 shipments of wildlife to be sold as exotic pets, Burmese Pythons among them (National Parks, 2010, pg. 24). Most Burmese Python owners soon realize that they are not fit to handle such an animal. A majority of the owners end up setting their pythons free into the environment, or in some cases the python will escape. Another large amount of the Burmese Pythons in the Everglades was freed from a snake importer’s warehouse during the 1992 Hurricane Andrew. All of these snakes migrate to the Everglades because it provides everything they need; a warm climate, vegetation for shelter, trees for the baby pythons to clime and waterways that provide the pythons with quick travel. All of these perfect habitat factors lead the snakes to begin spreading out into the multiple Everglades ecosystems. The snakes then began to reproduce. The Burmese Python is a very large problem for the Everglades the surrounding areas because it is a predator that conquers almost all other animals in its habitat. Burmese Pythons are known to eat white ibises, bobcats, great egrets, cotton rats, Key Largo wood rats, round-tailed muskrats, limpkins and even the all mighty American alligator. As you can see, this snake has no enemy, which allows it to push out all other native species, making it the dominant species of that area. The Burmese Python problem is growing bigger and bigger because Burmese Pythons reproduce very quickly. A single female Burmese Python can lay more than 30 eggs at a time. A recent study shows that the average female lays around 36 eggs per site. The females reproduce annually, so 36 eggs per year, compounded eventually add up to one big problem for the Everglades.

As you can see, the Everglades aren’t just home to a wide range of native species. They also house a large number of invasive and non-native species, specifically the Cuban tree frog, the Nile Monitor, and the Burmese Python. Although these 3 species are completely different in almost every aspect, the one common factor that they share is that they are a problem. When they slithered and crawled into the Everglades, they became a problem. Through their aggressive nature and out right dominancy on the animals in their part of the food web, they have created a severe impact on the species of animals that live amongst them. They devour almost all animals that they come across, and they prevent the native species from being able to reproduce in their habitats. This is causing the populations of the native species, such as the American Alligator, American Crocodile, native frogs, Burrowing Owls and Gopher Tortoises, to have a drastic drop. If these invasive species continue to cause this population decrease, they could eventually lead to the extinction of a species. Once a species is extinct, it will be impossible to get it back, and most will regret ever letting these animals take over. Never the less, invasive specie such as the Cuban tree frog, Nile Monitor, and Burmese python are a growing problem in the Florida Everglades, and something needs to be done to stop this problem.