The definition of endemic

@earthknight, @wdvanhem Yes the word endemic makes more sense at a small scale (e.g. Kilimanjaro , Lake Tanganyika, Madagascar) than at the scale of Africa for instance. Sadly, the places on inaturalist are rather political entities than natural regions so many endemic are not recognized as such.

@earthknight

Getting back to your specific examples though, I’d suggest that endemic is the correct term for the Asian Cheetah as species change over time (for any number of reasons) and it is currently native to only one place. If you start going into the history side (depending on how far back you go) then nothing is endemic to anywhere as species move around and change.

The point that I was raising is not how long ago it had undergone a drastic range reduction, but that this range reduction is entirely due to anthropogenic means.

There are relict species that had a large distribution in the past and have undergone a drastic range reduction due to natural phenomena such as climate or competition (e.g. Rupicapra pyrenaica ssp. ornata, Liquidambar orientalis). But their native range (i.e. the range which is the product of natural phenomena) is restricted to a specific place so they can be qualified as endemic.

@annemirdl Yes I did place the European rabbit as endemic to the Mediterranean region. They are extreme examples of endemic species that have been massively introduced elsewhere:

These cases are not different from Speleomantes italicus but the extent of their introductions immediately raises concern if one want to qualify them as endemic.

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An endemic is a taxa unique to a place or region, occurring in a limited area, not naturally found outside of it. Depending on the adopted criterion, the endemic may be a taxa with a range smaller than a specific area (e.g. 10,000 km2) or a taxa whose range is within the limits of a specific geographical area or habitat type. Species that occur mainly in a specific geographical zone or area, but extend slightly beyond this area and occur in close proximity to their main area of occurrence, are called sub-endemic species. Endemic can also be defined as taxa higher than the species if their occurrence is actually limited to a specific, relatively small area (islands, mountain ranges or lakes) …

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So I had a discussion with @jdmore who advocated that, according to inaturalist definition of endemism, if an endemic species is introduced outside its native range it loses its endemic status since it does occur somewhere else. For me, this is a too literal interpretation of “native and occurs nowhere else” which should be interpreted as “nowhere else natively

Anyway I think this definition should be something like “the native range of this taxon is restricted to [this place name]cf. my first post.

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Instead of trying to bend the existing definition of Endemic to an interpretation that does not fit its current very plain language, I suggest that you submit a Feature Request (using the required template) to change the language of the definition to something like, “native here and nowhere else.” Then the community can properly debate the pros and cons of the proposal, and the iNat staff will perhaps weigh in with a decision one way or the other.

Otherwise, debating it here will likely just encourage different users to apply Endemic establishment means inconsistently throughout the site, according to their personal favorite “interpretation.” Unless and until iNaturalist staff agree to make a change, I think we all need to follow the plain language of the current definitions, and not read anything else into them:

Any definition is fine so long as the range in concern is defined by geographical boundaries (eg. Borneo or "the Sulawesi subregion) rather than political boundaries (eg. “Malaysia” or “Indonesia”), because the latter are a human construct that wasn’t intended for making sense of natural landscapes

Of course, this thread is only to share views on this definition.
I just wanted to make a point and to ask your opinions on it:

Endemism is a natural phenomenon, humans can neither destroy (by introduction) nor create (by extirpation) an endemic species.

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Endemism is a human concept whether it is applied to natural geographic boundaries or to political boundaries. Humans decide which geographic boundaries to use, just as they decide which political boundaries to use, when calling something endemic.

While calling something endemic based on a political boundary may seem artificial and “unnatural,” it can have huge positive conservation implications, because conservation and management is often determined by political jurisdiction. When a jurisdiction has a species “unique” to their area, that can generate a lot of popular support for its protection. If that species has been widely introduced elsewhere, though, it unfortunately isn’t as easy to generate such support, whether or not we continue calling the species endemic there. It begins to dilute the meaning of “endemic” (to the general public) when the documented geographic distribution appears to contradict it.

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Endemism is a human concept whether it is applied to natural geographic boundaries or to political boundaries.

Saying that endemism is a “human concept” is true but provides no relevant information. You are right: the scale at which you define endemism can be subjective (albeit some endemism centers can be objectively defined!). However, if you mean that the concept of endemism is arbitrary or without any ecological reality, I strongly disagree.

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Every taxon is endemic somewhere. That is the ecological reality to me. What is arbitrary is the boundaries we choose - spatial, temporal, anthropogenic - by which to judge whether something is endemic at any given place and time.

Basing that choice on simple current geographic distribution (like the existing iNat definition) has its pros and cons. I mentioned one of the pros earlier, and so have others. The main con I have heard is that anthropogenic dispersal can change the boundaries of endemism.

Basing that choice on our best estimate of where something was native prior to the beginning of anthropogenic dispersal (what I believe you are advocating) also has its pros and cons.

Glad to see both debated, and I still think the context of a Feature Request would be a better place for it.

Yes, I will open a Feature Request but I wanted to discuss the purely biological aspects there first.

Then this is our divergence: I see it from an evolutionary and a biogeographical point of view. For me, endemism is not just a way of saying “this species occurs only there” but foremost the natural phenomenon by which a taxon is, or became, restricted to a particular place or set of places.

Endemism tells us many things about the past environment, biocenosis, climatic conditions, and even geology. Of course, there are definitely different types and degrees of endemism, but I maintain that there is much more objectivity than you suggest. With this biogeographical definition, there are obviously no anthropogenic boundaries. The “temporal boundaries” do not affect species that have always been naturally restricted to a particular place, while for relictual species by definition they had a broader natural range in the past*. For the spatial boundaries, first, there are fairly objective ways to define endemism centers. And second, given a particular place with spatial boundaries, there is no subjectivity in stating if the native range of a species is entirely contained inside or not. Only the biological relevance of this statement will vary as a function of the place.

For instance:

  • Salamandra lanzai is endemic to Italy (this statement is false: there are native populations outside italy)
  • Salamandra lanzai is endemic to the southeastern Alps glacial refugium (this statement is true and very relevant)
  • Salamandra lanzai is endemic to the Alps (this statement is true and relevant)
  • Salamandra lanzai is endemic to Europe (this statement is true but not relevant in most contexts)

This is why saying that Speleomantes italicus is no longer endemic to the Apennine because it was introduced to Germany or that the Asian Cheetah is endemic to central Iran because it has been extirpated from most of its wide range makes absolutely no sense for me.

*Of course there are species that expand their range without human introductions (e.g. Canis aureus). But these species usually have broad distributions in the first place, and modify their distribution usually in response to anthropogenic modification of the environment (climatic, land use, resources, etc.)

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This argument makes a lot of sense to me. Here in New Mexico, we have two species of plethodontid salamander (a Plethodon and an Aneides) that are found nowhere else in the world. While it’s correct to say that both are endemic to New Mexico, what’s really relevant is that one is endemic to a single mountain range in northern NM and the other is endemic to a different series of mountain ranges in south-central NM. Their endemism in two different mountainous areas is what’s evolutionarily/ecologically interesting.

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One clarification: if a species is defined as endemic to a particular political jurisdiction, such as a country or state/province, and that results in additional interest and efforts to conserve that organism, then I’m okay with emphasizing that status. It’s something that non-biologists who might be interested in their local natural heritage can appreciate.

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I think it’s worth considering that any line we draw on a map is a line we drew on a map. Political boundaries certainly aren’t intended to reflect patterns of biodiversity, sure. There is no taxon-agnostic natural classification of the landscape, though. If you want to capture variation in aquatic or wetland organisms, you’ll likely find a watershed-based landscape classification is the best bet. If you’re interested in alpine plants, you’ll probably find that the watershed boundaries are worse than useless, dividing every peak.

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I don’t think we diverge as much as you might think. I fully recognize and appreciate the scientific value of knowing where a species was most recently native without human influence. My “day job” as a Natural Heritage botanist for Nevada has given me the privilege of working for the past 31 years with about 140 endemic plant taxa, defined both by our state boundary and by their (usually) much smaller geographic ranges within. We also have two of the most prominent centers of endemism in North America (if not beyond): the Spring Mountains and Ash Meadows. And we pay just as much attention to another 160 or so taxa that we don’t call endemic because they also occur in neighboring states, but that are still just as vulnerable within their small natural ranges.

A few of our species have “lost” their endemic status over the years, mainly due to taxonomic re-interpretations. (And also gained a few by discovery of new species.) One example is a species that was formerly considered “objectively” endemic to the Spring Mountains of Nevada, but is now “objectively” considered conspecific with populations in the Wasatch Range of Utah. I use the term “objectively” advisedly here, because there is always an element of human judgment in such taxonomic decisions, and they are always subject to future further judgment as new research is conducted. All designations of “endemic” worldwide exist within a taxonomic context.

A few other species have “lost” endemic status to one area because apparently native populations have subsequently been discovered outside that area. We once thought we had dropped a state endemic because of an apparently introduced population that turned up along a California highway near our border. But that population ended up not becoming naturalized (so far). If it had, though, its formerly endemic status could still have been preserved, in an iNaturalist context, by marking it Native in its “naturally” endemic range, and Introduced outside of that.

My sense is that we wouldn’t be having this debate if species never became naturalized outside their “native” ranges by human-aided dispersal. Above I used the phrases “most recently native” and “without human influence” intentionally to illustrate the arbitrary decisions that are still unavoidable when defining endemism that way.

most recently native

Our designations of “endemic” depend on where we take our “snapshot in time.” As you noted, species ranges grow, shrink, and/or shift over time for a multitude of natural causes, not least of which “recently” have been Pleistocene climatic cycles. Some current centers of endemism, like strongly isolated “sky-island” mountain ranges, or actual oceanic islands, were probably centers of endemism throughout the Pleistocene (though their “taxonomic contents” may well have changed during that period). The Spring Mountains example fits here. Other current centers of endemism, climatically isolated wetlands like Ash Meadows for example, are likely more ephemeral in time and/or location, and less informative historically.

Where we take our snapshot in time:

without human influence

Very recent historical introductions are often (but not always) easy to identify. As one goes back a little farther, in some parts of the world the advent of human-aided dispersal is relatively easy to pinpoint in time. And the native ranges of species just prior to that pinpoint may in some cases be relatively easy to deduce. In other regions and for many other species, it only gets harder to make those calls. For these reasons I suggest that it is inherently impossible to determine where something is “native” objectively and consistently across the globe. It will always be subject to an element of human judgment.

So where does this leave things for iNaturalist? As I see it, we can go with either

  1. Endemic = “native here and nowhere else” and apply it easily to some species while having endless debates about many other species. Or,
  2. Endemic = “native and occurs nowhere else” and usually be able to objectively determine that status (spatially, if not taxonomically), and use the Native and Introduced options to add more information where possible and Endemic does not apply.
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My thoughts on “Endemic” are biased from having Howard Frank as an advisor. And he proposes dropping the term and using other terms. The problem of what exactly is meant my “here” remains though. Also, you can tell he worked on biological control from the divisions of adventive.
A. Native (= indigenous)

  • Precinctive (native and occurring only here)
  • Native but not precinctive (native and occurring elsewhere, too)

B. Adventive (= “non-indigenous”, arrived from somewhere else)

  • Immigrant (arrived uninvited).
  • Introduced (introduced deliberately by people)

More info https://ipm.ifas.ufl.edu/Education_Extension/gloss.shtml#5

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“Evolved in this region or arrived by non-anthropogenic means.”

If you think about it, this means that every species in the world was originally endemic to one locality – the locality where it first evolved. Probably one single hillside, or valley, or stream, or rock face. When we think of species so rare that they are known only from the type locality – that is how every species got started.

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Also many groups that are now endeic to one region were distributed much wider, so endemism is a concept of “here and now”.

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