An invasive species is a non-native species that could outcompete native creatures for food and other resources. Invasive species can be introduced in a variety of ways - some are exotic pets released into the wild by well-meaning owners, some hitch a ride on ships, trains, and planes coming from distant lands, and some even arrive by mail. Sanibel is a haven for its native wildlife, but our island is certainly not immune to these invaders. Let's talk about a few of them:
Reptile: The Brown Anole
If you have ever been to Sanibel Island, chances are you have come across the brown anole. These lizards were introduced to Florida from Cuba and the Bahamas. The native species of anole, the green anole, has been negatively affected by this alien species to the point that it is now rare to find one of these beautiful green lizards in your yard.
Amphibian: The Cane Toad
Have you ever been asleep on Sanibel in the early spring, and all of a sudden it sounds like a space ship is landing outside your window? This sound continues throughout the entire night and you wake up the next morning feeling tired and frustrated. The loud sound is coming from a very large toad called the cane toad. This animal was introduced on purpose to rid agricultural operations of pests, but it ended up becoming one itself. The large poison glands located behind its eyes kills many things that ingest the bufo-toxins secreted from them. Both pets and wildlife have been affected by this newly introduced species.
Fish: The Lionfish
Lionfish are native to the Indo-Pacific and, because of their beauty, are popular in the aquarium trade. These fish are wreaking havoc on our shores. Releasing around 15,000 eggs every four days, they reproduce rapidly and reach maturity at a young age of less than a year. Their abundance is not the only thing that makes this alien species bad for the ecosystem - they are vacuum cleaners of the sea and suck up as many native fish as possible, depleting populations and competing with other predators for valuable prey.
Plants: The Australian Pine
The Australian pine was introduced from Australia to Florida in the 1890s. To many locals, the breezy silhouette and shade provided by these trees is a charming part of our island home. Although magnificent, not everything about them is good. These pines will take over coastal areas, displacing native plants that are important to our native ecosystems, which support many endangered and threatened animals. The shallow root system was originally thought to help prevent beach erosion, but it did just the opposite, when other, more effective beach protecting plants started disappearing. Additionally, Australian pine roots make it impossible for turtles and American alligators to build nests in coastal communities.
Birds: The House Sparrow and The European Starling
The House Sparrow and The European Starling were introduced around 200 years ago in an interesting manner. Shakespearean troops in the United States wanted to make their plays as authentic as possible, so they would would release these birds during the shows. Although it took some time for them to settle in, these birds started breeding and making homes in urbanized areas. Both species inhabit urban areas, where they compete with native species. Additionally, they will seek out and destroy small urban crop farms and residential potted plants.