Originally Posted by Snipe
Originally Posted by ewest
native range - yellow
non-native area - red/brown
Does this actually mean invasive? No.. Means introduced there. Some feel that is however invasive.
Not dogging ewest, just using that key as an example. ....

No problem smile Just using the right word. This is not a cut and dry issue by any means. I did not use invasive on purpose and must comment on non-native. The way both are determined is very uncertain. Example - different studies including tracing genetics back have different interpretations on what native range is for many species. On SMB see the chart and how many rivers are involved. Fish can easily move by rivers, live there for generations, die out in that area and later reestablish. So is that species in that location, native or non-native ? Does it depend on if the second introduction is by man stocking or by fish swimming? In most places, close to native range, can one be sure how the fish got there?

Of course, some situations are clear. IIRC there were no LMB west of the Rockies until man moved them there - clearly non-native.