Hello! There has been something I have been pondering lately and its the use of the label ‘Endemic’ on inaturalist. I know endemic is often used for species confined to a small geographic range, but on inat it seems to be occasionally used to refer to species found exclusively or almost exclusively in one country, even if their range spans half a continent. Take the scarlet oak for example:
Found throughout most of the Eastern 3rd of the US and parts of Canada, but listed as endemic. Does this mean that any other species with a similar range are also endemic and not just native to the U.S.?
Is there another part of the endemic definition that I am missing here? Maybe I am just worrying over semantics, what are your thoughts?
Your understanding is correct. I think iNat stretches the definition a little with some species that are widespread within a country but still confined to just that country. It might be meaningful to some users and in terms of conservation efforts but I tend to consider endemism a more relevant term for species with a rather restricted range defined by a topographic feature such as a mountain range or an island.
Saying that a life form is endemic to X is the same as saying it “occurs naturally only in X and nowhere else”. The X could be a particular forest, province, country, continent, hemisphere… or even planet. The last case would be extreme in the sense that it wouldn’t be very useful, but my point is that it wouldn’t be a misuse of the vocabulary to say a sentence like: “all forms of life so far discovered are endemic to Planet Earth”.
Certainly the concept of endemicity is mainly brought into play for more localised areas because it’s for the flora and fauna of restricted distribution that we are most interested in the concept. The term “endemic” is very frequently used at the level of nation states simply for the reason that species checklists are often compiled for a specific country, or field guides published for a particular country, or wildlife laws declared for a particular country, for various social and political reasons of human convenience.
So, yes, the term “endemic” is basically meaningless without some contextualisation of scale (“endemic to X”). Without such explicit qualification, I personally would always assume the scale of reference was nation states.
“Endemic” doesn’t have a meaning without saying what area it’s endemic to. For your oak example above, it’s endemic to North America.
For the most part endemic is used to refer to small geographic areas like islands or mountain ranges, to distinguish between species that are restricted to those areas and those that may be native but are also widespread in other places. For example, most Hawaiian native plants are endemic to Hawaii, but quite a few – especially those found in coastal areas or with highly dispersible wind- or bird-dispersed seeds – are regarded as indigenous, meaning the same species is also found elsewhere.
In your scarlet oak example, it looks like there are records from Ontario but perhaps these are cultivated. If a native population is verified in Canada then immediately the species would no longer be endemic to the US. So it’s a rather artificial designation for this species since it’s based on a political boundary.
Hm ok, I think I understand now. So while endemic is usually associated with species with restricted ranges, it can also be used more broadly. Thank you all for your explanations!
And as if that wasn’t enough confusion, the same word has an entirely different meaning when discussing diseases. If we say, “Yellow fever is endemic in Angola,” we do not mean that it is found there and only there. What we mean is that it exists there at a relatively constant incidence, as opposed to epidemic, meaning that a disease suddenly increases in incidence.
A professor of mine tried to get different language introduced but it never took hold. Maybe iNat could adopt Frank’s terminology and abandon the word “endemic”.
Endemics and Epidemics of Shibboleths and other things Causing Chaos
Edited for clarity after getting shunted to another topic momentarily. Lesson learned? Don’t rely on which reply button you press to keep the discussion organized. Quoting is a better option if replying to something that’s not the most recent post. (threading and subthreading is not handled well in this forum).