From the Fall 2009 Conservationist for Kids
History of New York State Invasives
By Gina Jack
What is an invasive species? How do they get here?
We call them alien, exotic and non-native. They are the plants and animals that have arrived here from somewhere else and established a new home. Some cause no serious problems and live in harmony with our native species. Others create major challenges for native plants and animals, and for people. Having lots of variety in an ecosystem helps to keep things in balance. Invasive plants and animals limit the variety and upset the balance. If we learn about invasive species-what they are, how they travel and the features they have that give them their competitive edge-we can help stop them from spreading.
Alien, exotic or non-native: a living species originating from somewhere else
Invasive: an alien species that causes problems in its new environment.
Many species of plants and animals in New York State are non-native. Some, like honeybees, are very helpful. Some, like dandelions, are considered to be a nuisance but do no real harm. Others are like biological bullies. They arrive and take over, out-competing local species for space, or causing great damage. They don't bring their natural predators with them, so their numbers can get out of control. These bullies are the ones we call "invasive." They are very good at competing with our native organisms and winning. They take over and offer little or no benefit. They may even cause a great deal of harm.
Plants and animals arrive here in many ways. Sometimes they arrive by accident, such as when an insect is in the wood of a packing crate or aquatic animals are carried in the ballast water of ocean-going ships and unintentionally released into waters around the world.
European starlings were introduced (released on purpose) in New York City's Central Park in 1890 by fans of William Shakespeare who wanted to bring in each kind of bird mentioned in his writings. They've spread across North America, and can now be found from Alaska to Mexico. Starlings are so well established now, it's as if they are native. We say they are naturalized.
Purple loosestrife and Norway maple are non-native plants that have been sold at garden centers for use in landscaping. Their seeds traveled away from the gardens and the plants "escaped" and spread into wild areas. They crowd out native plants and don't provide food for native wildlife.