An invasive species is one that is not natural or native to a particular habitat but has been aggressive in its adaptation to the new habitat. Most of the time, the invasive species drive out the native ones and affects the ecosystem of their new habitat.
An example of a place with invasive species is the Florida Everglades. The Everglades is an enormous watershed that is fed by Kissimmee River and drains excess water from Lake Okeechobee. The habitat has several ecosystems that thrive close to urban areas. The environment is full of freshwater and home to many animal species. Invasive species are easy to find their way into the Everglades due to its proximity to human populations.
These trees were introduced to the Everglades back in 1906 in order to improve the landscape and to help in draining some overly flooded areas. The problem arose when the authorities realized that the trees grew significantly taller and denser than in their native habitats of Australia, New Guinea, and the Solomon Islands. As a result, birds that have a large wingspan were unable to fly as freely. In addition, the trees are extremely tolerant of fire and floods and could reproduce at a significant rate. Eventually, the authorities began getting rid of them through felling, herbicide, and introducing pests such as melaleuca psyllid to kill young trees.
In North America, there have been Asiatic clams for a long time but they were introduced to the Everglades in 1961. Native to Eastern Asia, these clams reproduce rapidly and do not need high qualities of water to thrive. It is possible that Asian workers introduced them as a source of food. Due to their high rate of reproduction, they displace native creatures, starving them of food and places to nest. The clams, whether alive or dead, also flourish around pipes, canals locks, and other places that may be problematic. However, they have become important in cleaning the water and a major source of food for ducks.
Native to Africa, Nile monitors have made an establishment in an area around Cape Coral, Florida, after they were introduced to the region through importation as pets. Introduced in the period around 1990, these reptiles are excellent swimmers and climbers who eat eggs. Because of this, they have affected egg-laying animals and birds like owls, and turtles. These opportunistic predators also prey on fish, other reptiles, small mammals, and other small prey. Native egg-laying species threatened by this monitor include diamondback terrapins and brown pelicans.
The Monk Parakeet is a small bird that is native to South America, especially in Argentina, Uruguay, and Brazil. Introduced to the Everglades in the late 1960s as pets, the birds are deemed to be pests who are detrimental to agriculture. Their classification as being invasive is based on their ability to populate rapidly and occupy large areas. In Florida, they are estimated to number up to half a million. In urban areas, they are known to make their nests in inconvenient places, like power lines.
These insatiable opportunists, which are native to Europe and Africa, were introduced to Florida back in the 16th century as a food source. Primarily, they require significant portions of vegetation for food and occasionally prey on smaller animals. Wild boars are known to be carriers of 45 communicable diseases or parasites, like the eastern equine encephalitis. One example of an affected native animal is the critically endangered Florida panther, which has been affected by trichinosis spread by the boars. However, the same affected panthers and other animals have come to depend on the boars for food.
Old World Climbing Fern
The Old World climbing fern has severely affected trees in the northern region of the Everglades. The fern, which was introduced in the late 1950s for unknown reasons, affects vegetation by creating a sun-proof blanket over them. Smaller animals such as deer and turtles have also been known to be trapped by the fern until death. The authorities have had a difficult time in coming up with a sound strategy of getting rid of the plants. Fire may work but it will spread rapidly and may end up doing more harm than good. A sound, albeit infective plan, is the introduction of biological agents that feed on the fern, which is native to tropical Asia, Australia, and Africa.
Native to Central America and Mexico, the Mayan cichlid was introduced to the Everglades around 1983. The fish spread widely from two initial habitats to occupying almost every water body in the Everglades. Introduced after being discarded from aquariums, the fish have the potential to grow to be quite large. Consequently, they became popular for sports fishing. They feed on grasses and a number of small creatures such as fish and eggs. The rare Everglades snail kite, which is a type of bird, is further threatened as their eggs are also eaten.
Lobate Lac Scale
While their method of introduction is unknown, the insect is known to infect a minimum of 94 native tree species in the Everglades like the wax myrtle. The insects may end up killing the vegetation they infest. Native to India and Sri Lanka, the insects were introduced to the Everglades in the late 1990s. The long-term effects are still under study.
This python is native to Southeast Asia and was introduced in Florida in 1979 through pet trade. This voracious snake has rapidly depleted local animal populations since its introduction and constantly battles with alligators. They prey on 41 rare species and 39 endangered ones. The park authorities are constantly removing them from the ecosystem.
This fish prefers habitats with slow-moving water, ponds, and similar places. Native to South America, the fish is an excellent water cleaner. In the wild, they usually grow larger than those in captivity do. The main sources of food include algae and weeds, which it competes for with birds and other smaller fish. Introduced after being removed from aquariums in the 1950s, these fish have been known to strangle birds that have tried to swallow them whole. Studies show that they are not disruptive of local fish populations in the Everglades.