You have probably been somewhere sometime when someone said to you, "You're not from around here, are you?"
It is usually not a compliment. Many people feel the same way about anything that is not from their home town, home state or home country. But, non-native isn't always bad.
When you think of things that are non-native to the U.S., it is easy to think of Kudzu, Burmese pythons, Asian carp, or some other non-native species that has wreaked havoc on the American environment. But we depend on many non-native species every day.
The only native meat that we regularly consume is turkey. Beef, pork, lamb, chicken and most fish on our dinner tables all originally came from other countries. Of most of the fruits and vegetables that we eat, only beans, squash and blueberries originated in North America. Peaches, apples and citrus came from China. Green beans, potatoes and tomatoes were developed in South America. Broccoli came from Italy and wheat from Turkey. Even American corn came from Mexico. Sure, they are all grown here now, but Toyotas and Hondas are made here now, too. Still some people will only drive a Ford or Chevy because they are "American" cars. If you stick with that philosophy for food, you will be limited to beans, squash and blueberries.
However, some non-native species really can become invasive and get out of control. Kudzu is one. This plant was originally brought to the United States and planted on purpose to help control erosion. It probably seemed like a good idea at the time, but here, kudzu quickly covers every plant in its path and kills native plants by blocking out the sunlight. Many other non-native plants have caused problems here, too. Chinese privet, Japanese honeysuckle, Japanese stiltgrass and multi-flora rose are some of the names you might have heard. Potentially, one of the worst is Bradford pear. Bradford pear trees, with their beautiful white blossoms, were developed from Callery pear trees and they were originally bred to be sterile. However, in recent years the Bradford pear trees have cross bred with other introduced pear species and they are now producing fruit spreading uncontrolled. Do some research on Bradford pear trees and you may want to cut yours down tomorrow.
When non-native species are introduced into a new environment, they often come without their native checks and balances that keep them under control in their original surroundings. Bacteria, fungi, beetles and wasps that evolved with a species help keep things in balance. Gypsy moths, hemlock woolly adelgids and fire ants are non-native species that initially flourished unchecked in the U.S. Now scientists are finding that predator beetles and wasps are better at controlling the non-natives than chemicals.
There are some common animals that we forget are not native to North America. Horses and pigs were not here until they were brought here by the early Spanish explorers. Wild horses in the West and wild pigs all over the country are out of control. The state bird of South Dakota is the ring-necked pheasant, a native of China. Rainbow trout came from the Pacific Northwest and brown trout came from Europe. Only brook trout are native to the Eastern U.S. Honeybees are from Africa and Europe. There are plenty of native American bees that don't live in large hives and are excellent at pollinating native beans, squash and blueberries. House cats are originally from Egypt and now there are millions running wild and killing native birds and mammals.
And finally, here are a couple of the worst non-native invasive species. The chestnut blight, a fungus, killed every American chestnut tree. Asian chestnut trees evolved with the fungus and learned to live with it. The Burmese python can grow up to 20-feet-long and 200 pounds and it is destroying many native species in the Everglades. The European house sparrow caused the decline of Eastern bluebirds by 90% in the first half of the 20th century. And white-nose syndrome, another fungus, threatens to wipe out many North American bat species. All of these species were not a problem in their native countries.
But, it is not a one-way street. There are American species that are causing just as much trouble in other countries around the world. If you visit the UK, don't ask anyone how they like our American gray squirrels. They don't like gray squirrels any more than we like European starlings. It is a complicated world out there.
Non-natives can be good or bad. But when a non-native moves in and takes over it often means bad news for the natives. Just ask any Native American.
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