Introduction

Invasive Species Defined

What's Being Done

 National Invasive Species Information Center

Submodule 5: Invasive Animals

Invasive Vertebrates

The bulk of invasive animals in this group are fish, mammals, and birds.

• Amphibians – freshwater animals that are generally introduced accidentally by pet owners or dealers, or intentionally for control of other invasive organisms. They can be very destructive to native animal species, preying on other amphibians and small mammals. Examples include the Cane toad (Bufo marinus) found primarily in Florida and the coqui frog (Eleutherodactylus coqui) in Hawaii.


• Reptiles – these organisms can occupy fresh, brackish, or salt water. They are general introduced to new habitats as released exotic pets or by pet dealers. Like amphibians, the major destruction caused by these animals is damage to native animals through predation. An example includes the brown tree snake (Boiga irregularis) that has caused much destruction in Guam.


• Fish – invasive fish are known to occupy all aquatic environments from fresh water to salt water. These animals cause damage to their new habitat by preying on native species, altering habitat, and perhaps introducing new diseases to native organisms. They are often intentionally introduced for sport fishing, or discarded by aquarium owners and pet dealers. The release of baitfishes by anglers has been devastating to some areas. An example is the sea lamprey (Petromyzon marinus) that has invaded the Great Lakes.


• Birds – invasive birds have been introduced to this country both intentionally, for pest control, or unintentionally, through the release of pet birds. Their impact ranges from competition with native birds for nesting sites to crop destruction. An example is the European starling (Sturnus vulgaris) found throughout the U.S. mainland.


• Mammals – invasive mammals usually include small animals and commonly rodents, such as rats and mice. Most were introduced unintentionally through shipping and human migration. A major nuisance species that was intentionally introduced but unintentionally released is the nutria (Myocastor coypus), a South American rodent imported for fur production.