Non-native species?
 

This topic is being discussed in another thread, so I figured I would try to clear up some confusion in my own mind about the term "non-native".

What exactly defines an organism as being "non-native"? Physical boundaries being crossed intentionally or accidentally? Human hands must be involved? Or can any other organism that introduces another organism to some place it has never lived before play too? Is there some time limit as to when any "natural" form (whatever that might be) of migration of a species has to have already taken place before the door that considers them as being "native" is shut?

Seriously, this has always puzzled me. Sort of like the designation of "locality" animals. Are there any definitions that are not just arbitrary in nature, and push come to shove, a definition made up by a species that is itself non-native in most of the habitat it is now found in?

Nonnative has a variety of definitions. In general, the definition that wildlife biologists use is synonymous with exotic, e.g. a species that was either accidentally or intentionally introduced by humans to a novel area and/or environment. Nonnative by itself does not necessarily equate to bad, as many of our crops and domesticated animals are, by definition, nonnative.

In contrast, animals and plants that have undergone natural expansions into novel areas and/or habitats are generally managed as natives, unless those expansions were facilitated by human development. For example, cattle egrets got here by themselves all the way from Africa and are a recent addition to North American fauna (in the last 50 years).

Examples of nonnative species include woodchucks, coyotes, and armadillos. All have expanded into the southeastern United States due to anthropomorphic changes in habitat and/or social dynamics which allowed their establishment into new areas. Woodchucks utilized road corridors and other rights-of-way to expand into the Southeast and rarely occur outside these habitats. Armadillos are weird and I don't know their history. Historically, red wolves prevented coyotes from expanding into the Southeast, but with the human-led extirpation (and functional extinction from the wild) of the red wolf, coyotes expanded into an area that was vacant of a large canid carnivore. This has led to some challenges with white-tailed deer, wild turkey, and northern bobwhite management, so the coyote is considered (by some, mainly those in game management) as a nonnative predator.

Excellent post/explanation, Vanessa.

:iagree::iagree::iagree:

Hello snark.

Sent from my C6725 using Tapatalk

Are you using this comment to refer to an imaginary animal, or what?

There must be something that I am missing here..

LOL, it's nothing more than a snarky comment from a snarky user with a dubious rep. Not even clever.

Beats me.. :shrug01: Maybe I have an unknown admirer or something. Probably "or something"......

When I first read the comment I too thought it was just a mean spirited comment. Then, I looked up the word 'snark' and one of the meanings is 'imaginary animal'. So it is possible that this poster is agreeing that a 'locality' or 'non-native' animal may be an imaginary distinction in some cases.