One, and only one

I was going to title the thread, “One,” but then I remembered that the site settings don’t allow such a short title.

I wonder how many taxa are represented on iNaturalist by one, and only one observation? Yesterday, I wanted to look at the Congo Peafowl, and this is what I found.

Three-and-a-half years, nine agreeing identifications, and it is the only one.

Has anyone else found a taxon like this?


I’d bet a good number of the observations in this project are the only observations for their taxa:


If my ID is correct, then I have an observation that is an only one:

Edit: Species is Callirhytis elliptica, a root gall wasp


From my observations:
I’m sure from insects there’re hundreds of such species, if not thousands.
Quick check of African observations and 14 species of birds with 1 observation on iNat, probably same number of mammals. From interesting ones are records from 1980 2007 2008 2009
And this unique-looking wagtail


It’d be cool if there was an easy way to search for these taxa. Or for the ones that have no observations at all, so we can go hunt for them in particular.

I found this species completely by accident recently, and so far it’s the only observation:

Assuming my ID is correct, this is also an only observation:


A lot of my observations have been the only one of the species (or even genus in a few cases). Over time as we’ve gotten more observations in my area I have fewer and fewer observations where mine is the only one.

When I made them these were the only observations of the species on iNat:

There are a bunch more, but I’m not going to go through and hunt down the rest that were or still are the only observations though.


Very much my ID discovery highlight so far: Bill Gates’ Flower Fly (Eristalis gatesi) · iNaturalist endemic to Costa Rica.


My only one for the list. Except for probably some fish I think you’ll be hard pressed to find other European vertebrates without multiple observations:

Here’s one for which I could add a second:

btw… How come that has been renamed? I have never heard anything but Hula painted frog as common name. Much more precise and the established, widely accepted name. Appears someone has taken it upon him- or herself to apply a political renaming that, quite frankly, seems entirely out of place on iNat

Why does the number of observations appear as the descriptive text for the species?

“Doleschallia dascon is a species of insects with 1 observation”

That makes no sense.

edit: Just noticed this applies to a lot of these species. Doesn’t make it any more meaningful.

That project also includes at least one observation that shouldn’t be in it, though:

Bcause there’s no linked Wiki article.


Why if it’s underscribed species and there could be no other photos?

So if someone adds a second observation the text will automatically update accordingly?

Oh well… while I don’t see how that text provides any value I guess it doesn’t do any actual harm either, so okay

Okay, sorry.

Somehow I missed the “undescribed” comment, hence I thought it was just a random specimen that hadn’t been identified beyond the level of genus. My bad.

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That’s a pretty cool observation! eBird only has a single image of the species too, and it’s from a camera trap. However, there are some other captive observations of Congo Peafowl on iNat.

Yes, it just stays there to cover space, you or anybody else can create a Wiki article about taxon and it’d take the place, there was a post somewhere on the forum about such initiative.


Their are probably a lot of microscopic taxa with only one observation, (, here is one that I have made personally with only one observation


I found out some people have created a WUNDERKAMMER for their observations:

I have a couple…
Aubrieta thessalia
Campanula oreadum

It seems someone used my photo for the Campanula as the default photo. I’m glad they did. I didn’t have the guts to put it up myself because I’m a little paranoid about misidentifications. I’m wondering if I should put my Aubrieta observation as the default photo for that species, but I’d like it to at least be research grade before I do so. What do you guys think?