I’m having a rather heated debate with a certain friend about the definitions of “endemic” and “indigenous”, particularly in relation to plants and animals. My understanding is that “indigenous” means something can be found naturally in an area, but also in other places as well, but “endemic” is something that can be found *only *in a specific area. For example, the American Heffalump is endemic to the whole of the United States, but the Arizona Woozle is endemic only to Arizona.
The point of contention is that said friend is claiming that a tree found only within 40 ha of forests in a single island cannot be defined as indigenous to the island, it can only be endemic to those 40 ha. I take the opposite opinion, that since those 40 hectares are part of the island, then the tree is endemic *specifically *to those 40 ha, but indigenous to the entire island. I illustrated this by drawing a circle marked A, I split the circle in half, one half marked “B” and one marked “C”. I drew a figure of the specific tree in B, and species of trees common to the entire island in both B and C.
Following this, if said tree is transplanted from B to C, then the tree will no longer be an endemic species to C, but still an indigenous species to A. Common trees can be moved to either B or C, and provided none exist outside of A, are both endemic *and *indigenous to A. If I move any of the trees outside A, all become neither indigenous nor endemic. In a nutshell: The term “indigenous” encompasses everything within its area including all “endemic” objects therein. Something can be indigenous without being endemic, but nothing can be endemic without being indigenous.
Is there something wrong with my understanding or is there some better example to illustrate this?
For something to be (ecologically speaking) indigenous, it has to occur within that ecosystem naturally. If it’s found only there, it’s also endemic to that ecosystem.
It’s possible to be both indigenous and endemic at the same time, sure.
I’m trying to figure out if part of what you two are arguing about is whether or not a given ecosystem encompasses the whole island or just the (sub-?) region where the tree is found…
Is your friend suggesting the tree is indigenous only to those 40 ha? That sort of discussion would break down into an argument of how to define the region/ecosystem where you are saying the tree is indigenous, but in that case the tree is both indigenous and endemic to those 40 ha if it occurs there naturally and is not found anywhere else.
You are basically correct; however, “indigenous” says nothing about whether or not a species is confined to a particular area. It just indicates the species is native or naturally-occurring there.
From Merriam Webster:
In your first example, the American Heffalump is endemic to the whole of the United States, and also indigenous to the entire area. If it naturally occurs in Arizona, it is indigenous there but not endemic. The Arizona Woozle is both indigenous and endemic to its Arizona range.
In your second example, you are both wrong, however. The tree is indigenous and endemic only to the 40 hectares where it occurs. (Of course, you can say in a loose sense that it is endemic and also indigenous to the island as a whole. This is often the sense in which the terms are used.)
I’m not going to try to sort out your third paragraph. Any place the tree is transplanted (not naturally occurring) it is neither endemic nor indigenous. However, transplantation does not affect its status as endemic or indigenous in its area of native occurrence; it can still be considered to have that status. A good example is the Ginkgo. It was originally endemic to central China. It is now widely planted on city streets. However, it can still be considered a Chinese endemic.
I am also not aware that endemism technically requires the species to be indigenous. In theory a species transplanted by humans to a non-indigenous region would be endemic to that region if it ceased to exist elsewhere, I suppose, although I don’t think the term is ever actually used that way by naturalists, who are using the term to suggest a natural event (even if that’s not technically in the definition).
Colibri?
I’m not an ecologist; I just got drawn into this because it seems like such a pedantic argument.
Which is something I’ve considered. The specific tree is called the Cebu cinnamon tree, Cinnamonum cebuense, and while the tree is found only in such a small area there is nothing intrinsically unique about that area in the island it is located (that is, its conditions would be more or less similar to other areas in the island with similar geographic conditions - only with no such trees in it). The trees existing in the small area can be said to be the only ones that survived from vast primary growth forests.
The argument basically came from his objection to transplanting “indigenous” plants in denuded forests, which he then goes on to say won’t “survive there” because they aren’t endemic. Which then leads up to my attempt to explain that indigenous would mean trees that were naturally there all along, and by definition include endemic species also. He then goes on to confuse the term “indigenous” with “introduced” - going into a soujorn that ultimately everything is “indigenous” if you look into a system large enough. Hence planting “indigenous” species would also mean species not suited for that environment.
While I admit that on some level it holds merit, I’m sure there’s an error here somewhere. What’s stopping an African elephant from not being “indigenous” to Asia, for example, if “looking at large enough systems” is enough to decide? They’re both on the same planet. You can imagine arguing with this person had been very frustrating.
No, as used by biologists “endemic” means native to and naturally occurring in an area. An introduced population is no longer endemic, even if the species no longer occurs elsewhere.
“Endemic” can be a little confusing, since it actually has two meanings, the first of which overlaps with “indigenous.”
From Merriam Webster:
So the first definition just means native to, basically the same as indigenous. But the second sense, restricted to, is the sense usually used by biologists.
Sometimes pseudo-endemism can be created by range reductions caused by humans. For example, today the Whooping Crane is restricted as a naturally breeding species to a small area of Canada. However, it is not really a true Canada endemic because it formerly bred through much of North America. (The situation is further complicated by a re-introduced breeding population in Wisconsin, within the species’ original natural range.)
Au contraire! I would find it a delight. He sounds like such an insufferable pedant.
To your point about how large a system: Exactly so, until the word loses meaning.
We are all indigenous to the Universe (as far as we know), right?
The reason we need folks like Colibri is to let us know what the practical range of use is for the terms in order for them to retain meaning useful to experts in those areas. If you just used a dictionary definition as an arbiter, indigenous would be fine for use with the entire earth as the “ecosystem” and “endemic” could be used for some zoo containing the last remaining passenger pigeon. Neither of those are very useful practical applications of the words.
If you are talking about practical conservation, no one actually in the field would take the approach espoused by your friend. Most conservationists are going to take a pragmatic approach, rather than depending on arbitrary definitions.
Conservationists are going to take into account historical considerations as well. If this tree probably or possibly once occurred in these degraded forests, they would be very likely to attempt planting it there, regardless of whether there was definite information on whether it once occurred there.
I used to work for the New Zealand Wildlife Service. The bird I worked with was the Hihi or Stitchbird. (The first reference on the Wiki page was written by me, and the last one by one of my students.) At one time it was found all over the North Island. In the 1880s it became extinct everywhere but on one small island, Little Barrier.
As part of the conservation program, in the 1980s we started introducing the species to other predator-free offshore islands, even though there was no record of the species ever having occurred there. Unfortunately, they haven’t done too well, mainly because the islands are small and don’t have the diversity of food resources. More recently, the species has been reintroduced to parts of its original range on the North Island. It remains to be seen whether these will persist.
