An invasive species is an animal that is not originally from a specific ecosystem that has increased in numbers enough to cause harm to the environment.
In order to qualify as invasive species, the animal itself must
- Reproduce quickly
- Grow quickly
- Spread in population aggressively
Invasive species can be harmful to native animals that already live in that ecosystem through many different ways.
- Eating other native animals
- Eating food resources of native animals
- Carrying diseases that can affect other native animals
- Eating or crushing the eggs of native species, making it harder for them to reproduce
Invasive Species can end up in new eco-systems through many different ways
- The Pet Trade (Many Burmese pythons were either lost or intentionally freed into the Florida everglades where they are now an invasive species there and have become a threat to the local alligator population)
- Intentional Introduction (the cane toad was introduced into Australia to stop beetles from eating crops, but now has aggressively spread throughout northern and western Australia)
- Ships (rats stowed away on various ships and ended up on a variety of tropical islands where they quickly spread and multiplied, consuming the islands resources.)