How to handle global conservation statuses for non-native taxa

Green ash, Fraxinus pennsylvanica is considered Critically Endangered by the IUCN, a status that is technically global in scope as I understand it. However, it’s an introduced species in Europe.

On observations in Europe, it ends up looking like this, where the red CR indicates it is a threatened species and the pink exclamation point indicates it is introduced in the location the observation was made:

Should the conservation status be edited to reflect only North America, should there be a way to automatically suppress global conservation statuses on observations in places where the taxon is introduced, should it stay how it is, does it depend on the taxon/situation, or something else?

Also I have a bit of deja vu so perhaps this has been brought up before, but may have been on the Google Group or in an old flag or something.

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should stay like this, as this expresses the situation clearly

If the dangers/ threats it faces are global, it really shouldn’t matter if it is introduced or not, should it? Or is there some conservation philosophy that something should only be preserved where it is native?

Generally speaking, preserving a species within its native range makes usually more sense, as the genetic diversity within the native range is usually higher than that of introduced populations. Introduced populations are however sometimes all that is left of a species. Introduced and cultivated - captive populations can therefore be seen as important backups in the current extinction crisis.


This is an interesting question and one that deserves a lot more attention.

Another good example of the failings of the global ranking system is the case of Delonix regia

It’s listed as Least Concern because it’s widely planted as an ornamental tree around the world, but that ignores the fact that in its native habitat in Madagascar it’s endemic to the dry deciduous forests and is locally endangered.

This means that a tree that’s in danger of becoming extinct in its own habitat is being ignored because people like planting it as a street tree in regions far removed from the environment it is an integral part of.


If you have a look into the IUCN assessment of this species, you will see e.g. on the map given there, that introduced populations of Delonix regia were not included in the assessment.

If you find an error in the data presented in the assessment, or if you have data on (wild!) population size and trends of the species, then we should have a closer look at this.

I am pretty familiar with the IUCN assessment process, having gone through it with the species I’m working with and, due to that, I also have an unfortunately deep knowledge of how slowly and inaccurately the Red List is updated.

The critical sentence in the assessment portion of Delonix regia is the following:

There is no precise information to assess the population size and trends of the species.

In cases like that assessment is left at LC or Data Deficient until more info is gathered.

They do acknowledge that more work is done to properly assess the species:

However, its native habitat the dry forest, is fragmented and degraded, and continues to decrease in quality and extent; these trends should be monitored to determine whether the population of this species is declining.

Within Madagascar the species is reported as listed as Endangered (local areas respond more quickly to changes in status than the sometimes decade plus that the IUCN Red List takes), but I can’t find a Madagascar based list to provide as a source. I may have to mail some friends working there to see where the gov portal for that sort of info is.

The IUCN Red List is so inaccurate on certain species that I’ve stopped recommending it as a reliable source of info. It’s a good quick overview, but it’s updated far too infrequently to hold relevant info in many cases.

That’s unfortunate, as it’s still one of the only places of consolidated information to go to.

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I like our discussion but it might be off-topic. will pm you earthknight

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I agree with @mreith that it should stay as it is. I think it is good to know when one is looking at a species that is endangered in its native range but introduced beyond that range.

Where it gets sticky, though, is if obscured taxon geoprivacy is needed because of conditions in the native range. In most such cases, I would think it preferable not to obscure such taxa in the introduced portions of their ranges, but only where native and endangered. Knowing precise locations of introduced individuals or populations of endangered species could be very helpful for conservation purposes. (An exception to that might be for introductions made specifically to create refugial populations that are themselves vulnerable.)

So in most such cases, I’m thinking the following might be appropriate:

  • Create a global IUCN status for the taxon, with open taxon geoprivacy.
  • Create a second, geographically constrained IUCN status for the same taxon for its native range, with taxon geoprivacy set to obscured. (or as many such duplicate statuses as needed to cover the entire native range)

Not having tested it, I think the result would be taxon obscuration for observations within the native range, and open taxon geoprivacy everywhere else (while still showing the endangered status).

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