How about reporting extirpated or eradicated populations of endangered species'?

My question is about formerly know occurrences of rare plant species’ which have gone lost for several reasons, as for example approving extermination by expanding quarries.
The past days i searched for the few populations of the “European fur fern”, German “Pelzfarn” known in Austria:
While i could find Styrian populations of the poikilohydric, drought tolerating fern upon serpentine rocks, i had to confirm the ultimate lost of the sole former population in Burgenland. This occurrence had been first reported in 1962 at Burgenlaendische Heimatblaetter 24, while in 1992 there shall have been remained just 5 plants at the very edge of the rapidly grown serpentine quarry. Soon thereafter these will have got blasted away, thus eradicated.
When i inspected this quarry yesterday, the ultimate loss got soon clear. See the Steinbruch Postmann

Maybe it made sense to report the loss of rare species, but how could it be done in a useful way, without creating a mapped, but lost occurrence? There needed to be an own category for likewise extirpated observations.


If you saw something at that date, there’s no reason not to upload an observation (with or without photo), there’re thousands observations of specimens no longer existing.


Thanks, Marina!
For sure i saw other plants and took photos, but the eradicated fern and its place has gone, been blasted away, so there is nothing last to see or to documentate.
When creating a report with yesterday’s date, this was clearly misleading. I might perhaps take a past date, when it was observed by someone else, though this would not tell about the loss, what is my intention. We may well verify the presence, although not the absence of organisms.

If you want to document the abcence, you can create a trip and add the species in a target list, that way it will be shown as having no observations through the trip, otherwise, if you want to show species was there, you can create a casual observation with the date you saw it there the last time before eradication.


iNat doesn’t focus on absence records, so there isn’t a way to make an absence an observation. Absence data are always more difficult to document and use in some ways than presence data, since they are never as “definite” - we can’t be sure that a given organism isn’t there, only that we didn’t find/detect it at a given time/place. I do think the goal of documenting extirpations is a valuable one - iNat just isn’t the best place for these kinds of records.

I think @marina_gorbunova’s suggestion may be the best option for iNaturalist. You could also make a note on an observation that another species was not found with it, though I don’t think this accomplishes what you want.


Thanks, Chris! You’re right, iNat is not the best place to documentate extirpation, at least there is no propper way to do so, and such option was likely too much of effort in relation to it’s benefits. Since you argumented:

i liked to answer the following. This is right in general, although there are exceptions, as the above mentioned population of a very rare fern, which needs the special site conditions as given at the blasted rocks, which are obviously gone, together with the eradicated plant. In this case i may be sure, that the organism in question is no more present at the site.

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I’ve been tempted in cases of local extirpation of endangered species due to human activity to take a picture of the site, ID it as Homo sapiens, and explain in the description what human activity at the site led to the extirpation of the species that were there previously. Not sure if that is an appropriate use of iNat but that’s the best I can think of for now.


Best thanks for all responses! I do think that Marina’s suggestion to create a trip with added target list was a propper way to documentate the ultimate loss of species, or that such could not be found within an area at a certain date. However, i didn’t consider or try to create such trip, am still learning to use iNat.
It’s a pitty and a shame that a very rare, yet endangered species got lost in that place. Our human, economic ratio will always compare conflicting benefits. In this case: “how many people may earn their living by widening the quarry?” versus “for what use at all are those few ferns, no matter if rare or not?”

Kind regards