NATURE NOTE - Number 91                                                                               April 28, 2024


Invasive Species is almost a “dirty word” in many circles of nature lovers and environmentalists.  Many groups, including scouts, dig, pull, and whack away at invasive plant species whenever they can.  We may have visions of the snakehead fish, that can walk on land, coming up our front steps.  Everybody is against them. But hold on.  First, let’s define…

Our Current Topic:  Invasive species

Normally it is an introduced plant, animal, or disease that is not native to the new area, but establishes itself in the new area and expands from its original site of introduction and causes harm to native species, humans, or the economy, and competes with native species for food and habitat. 

Sometimes the introduction of invasive species has been intentional.  Sometime it has been unintentional.  Sometimes there was a good reason – at the time - for the introduction, such as controlling roadside erosion by state highway departments when they introduced Kudzu vines.  Or maybe when the early settlers brought over the House sparrow (same as the English sparrow) to remind them of the sounds of nature from their old homeland.  Then there were the fox hunters who brought in the Red fox to provide them with sport.  The blight from Asia that decimated the American Chestnut, or even COVID, are examples of diseases.  Sometimes a species was introduced from its native range somewhere else in North America to new area, where it flourished.  For example the yucca plant from the southwest, or the Purple Finch from out west to New York (originally).  Even the National Park Service introduced non-native trout to parks out west to attract more sports fishermen, then had to backtrack when they found out the new species were pushing out the native species.  Other species have been released by humans when they didn’t know what else to do with an unwanted pet, such as the pythons currently overrunning the Florida Everglades, or domestic animals that became feral, such as the wild boar.  Fishermen have played a large role in introducing invasive species of fish and amphibians (used as bait) into native streams from somewhere else.

Some species show up in a new area by their own movement from an established range, such as coyotes and now the Armadillo (See NN # 52). These are not technically invasive species since they moved on their own initiative, but might be treated as such if they become a nuisance or threaten native species.

We Americans aren’t innocent in this species transfer either.  Examples of North American wildlife going outbound include the Grey squirrel to UK and Europe replacing the native red squirrel, and the exportation of the American Bullfrog to overseas locations to provide for commercial sale of frog legs as food.  Many escape into the wild, multiply and eat native prey. 

So what can we do about invasive species?  Can we eradicate them?  Probably not.  In most cases, unless detected very early in their new home, they are too well established for hope of total elimination.  Can we control, to some extent, the additional spread?  Maybe.  But it can be expensive and very complex.  Think about totally eradicating the Kudzu vine, or the Starling, or the Ailanthus (Tree of Heaven) from our landscape.  A very complex program of cooperation would be needed between the scientific community, many parts of society, legal issues, and whoever is paying the bill.  Probably not very realistic in most cases, so we might just plan to live with invasive species and control them as best as we can.  Obviously the best solution is to not allow any additional invasions.  This is where programs like the Department of Agriculture’s Animal and Plant Inspection Service (APHIS) are so important it catching potential invaders at the border.  State agencies try to prevent the spread of insects such as the Spotted lantern fly, or the Gypsy moth, or the Emerald ash borer from one section of the country to another.  There has been some success in doing this, but it has not totally stopped the spread.  Also, to complicate matters more, many species have been brought into this country in the past  that could be defined as introduced “invasive” that are now routine in our life, like potatoes (South America), pears (Central Asia), boxwoods (Egypt), tulips (Central Asia) and many more.  Maybe these are not harmful, but they compete with native plants. Then there are all sorts of tropical fish, birds, and reptiles that we  call pets, as well as domesticated mammals.  The bottom line is that most invasive species are here to stay, welcome or not, so learn to live with them, and control them as you can in the right circumstances.  To think we can rid our environment of them may be unrealistic.


It might be interesting to have your scouts make a list of invasive species and discuss them, in terms of how they got here, what harm they cause, what native species they compete with, and what can be done about them.  (Don’t forget the stink bug.)  I’m sure if you bring up the subject, most scouts will have comments about how they are bad and we need to eliminate them.  Maybe your troop has been involved in a project to eliminate (control?) some unwanted plant.  Make sure they understand the depth to which most invasive species have become ingrained into our ecosystems and society, and how elimination is virtually impossible.  Maybe with a lot of time, energy and money, some can be controlled. But the main thing the scouts need to understand is that they should never take any action to make matters worse by transporting firewood into our area from a Gypsy moth infested area, or releasing a pet into a natural area, or sneaking some plant or moss in from a foreign country.  If we all do our part maybe we can help control it in the future. 

Thanks for reading NATURE NOTES again.  Contact me with thoughts, ideas or questions.

Bob Garst

This email address is being protected from spambots. You need JavaScript enabled to view it.