Using iNat for invasive species monitoring?

Hey folks, I’m giving a talk to Cal-IPC on using iNat for invasive species monitoring in a month, and I was hoping some of you could tell me stories about your own use of iNat for this or related purposes. Specifically, if you have used iNat for invasive / introduced species detection and/or monitoring,

  1. Can you provide specific success stories? E.g. we noticed the introduction of species X and were able to get an early start on managing it as a result.
  2. Can you provide specific failure stories? E.g. we thought this would be a good tool for detecting novel introductions but manually monitoring new records on the site turned out to be too laborious.
  3. What other tools do you use in addition to or instead of iNat? How do the different tools serve different purposes?

Right now I’m probably going to argue that the large volume of iNat records in some places makes iNat good for early detection if and only if you can devote the person-hours to monitoring new observations on the site, and that it’s pretty bad at mapping populations. Am I wrong?


Check out the mapping for healthy forests Vermont project. Like you said it’s a great place to find and keep tabs on new occurrences and distributions of invasives as well as phenology and which habitats they are invading but yeah we haven’t used it to revisit the same populations repeatably on a consistent basis and as discussed often here there’s no easy way to collect negative Data.

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I’m the admin for the Invasive Species of the Coachella Valley project for the Low Desert Weed Management Area in Riverside County, CA. I think the project has been useful as an outreach tool both for presentations to the public and by letting iNat user know that some of the things they’re discovering aren’t necessarily supposed to be there. I can’t find them now, but I’ve had a couple conversations in observation page comments about the best way to remove fountain grass, etc.

@kueda I think your closing point is correct in that it requires a lot of time monitoring new observations and adding them to the (old-style) project to be useful. It would be great if observations of invasives would be accompanied by something more eye-catching than the little pink exclamation point to raise awareness of some of these species.

We have used inat observations on at least a few occasions as a rapid response tool to respond to Stinknet infestations in our area. I spotted the new observation on iNat and we removed the plants the next day. However, I think in most cases our hands are already full with the infestations we know about, so mapping new ones is not adding much value. I’ve also been exploring using iNaturalist for mapping populations by just making lots of observations - I think I have the (very much unwanted) distinction of being the world top observer of Sahara mustard, tamarisk, fountain grass, and schismus.

We’re starting to use the Calflora weed mapper tool as well, but I don’t have enough experience with it yet to report back any useful information. Unfortunately I can’t make it to the Cal-IPC conference, but there should be plenty of other LDWMA folks there - I’m looking forward to hearing their thoughts on your talk!


In my opinion, the iNat database provides the most complete dot maps for two invasive animals in western North America that I’m interested in: Red-eared Slider and American Bullfrog. No success story associated with these, but in terms of providing info on where they are and where they’re likely established, the iNat maps are where I go.


For regional context, Dittrichia graveolens is one of the highest priority weeds on Mt. Tam due to its affinity for nutrient-poor compacted soils and gravels – usually this restricts it to roadsides and such but that also describes serpentine soil, with rare plant implications… It’s also mostly absent from the core of Mt. Tam despite its commonness along adjacent urban thoroughfares. Really a perfect early detection/rapid response target. I manage something like 2 dozen patches on the mountain but had not known of this one. Now it will get annual attention (2-3 visits through the summer, as the plant may germinate in waves) until it’s eradicated.

And yes, you may infer by the Calflora link in the comments that iNat doesn’t serve me well for the level of mapping resolution that my protocol requires. My org uses the professional-grade subscription side of Calflora for mapping, labor tracking, population history stacking, and treatment data. I think you’re spot-on in your thesis.

iNat projects may also help cut through the noise, as many involved in early detection have a species watchlist that can be plugged in. (side note is there a way to upload a plant list to a project without manual taxon by taxon pasting?)


Thanks for the input and stories so far, please keep them coming if you have them!

For traditional projects, if you go to the project list you should see an Add Batch option that will show you this:

…and that might still work. I would definitely try it on a test project before trying it on a real project, though. I don’t believe we have functionality like that for rules on a collection project, though.

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Probably not helpful, but users will in general once in a while post observations of an invasive species (eg. Lantana camara in Hong Kong) so overall there may be some decent data in terms of distribution, time period etc. So maybe you might find something if you search for observations of a certain invasive species in a particular location.

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Here’s an article I published a month ago featuring data from iNaturalist to track further expansion of a non-native spider species in the U.S.:

I wouldn’t necessarily call it an “invasive species” as it’s hard to tell if it’s displacing native species or not. I also used data from BugGuide.


NZ’s Dirty Dozen campaign:

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For Lycorma delicatula in North America, I got the impression from some records that professionals may be monitoring the records from affected/potential states, as the circumference of reports widens here. If you browse those records (particularly the farthest outliers) you may be able see and contact one of them for comment.

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The National Invasive Species Council folks are fans of iNat and have been trying to use it in the DC area in this Invader Detectives project.

In their case, they have lots of non-native, well-established species that they don’t care about, so they want to exclude those (along with all of the natives). This means they have an extensive list of exclusions. Being able to automatically exclude the native taxa would be a big help, as right now the project is predominantly catching those. I think they have 18K species on their exclusion list.

They have been working with iNat data for a while (5 years?) through an EOL-based tool called FreshData. My understanding is that it allowed them to more easily exclude their “boring list” to focus on the species that could represent new introductions to the area that require attention.

I’ll email a link to this thread to the folks I know who are involved so they can chime in and correct anything that I got wrong.


Our “Dirty Dozen” was a focused effort on the worst known invasives, but the idea of watching for new stuff emerging is interesting! I would imagine there would be url length restrictions that would prevent a search filter from excluding all known taxa from a location. Would it be possible to search on taxa that are not in a list, or to create a project on that basis? We have the New Zealand Checklist which is kept fairly up to date:


Literally the first observation I ever uploaded to iNaturalist was this documentation of Spotted Knapweed, a new invasive plant discovered on Balcones Canyonlands NWR on June 7, 2014:
At the time, it was the first documented record of this noxious weed for Texas. It was discovered on a Native Plant Society field trip to the Refuge and identified by Dr. Art Gibson who had recently moved to central Texas. I returned the next day, removed all the plants I could find, and notified Refuge staff to scour other similar areas. They found a few more plants and managed to nip the invasion in the bud. Continuing monitoring of the area suggests that those initial control efforts were successful. I am told that the story of this discovery and the control efforts made their way (as a success story for early intervention) into the book entitled “Unnatural Texas?” by Robin Doughty and Matt Turner (Texas A&M Press, 978-1-62349-705-7).

Happily, in this case, “monitoring” of this invasive species on Balcones Canyonlands NWR has produced no new observations to upload to iNaturalist! Hopefully that will continue to be the case in the future.



This year in Portugal an university started a project to monitor the appearance of invasive marine species in our south coast (Algarve). Here’s the link:

Recently there was also a surge of Asian wasps in Lisbon which led to closure of a public green area. There were records, I think some persons wanted help in identifying the species that were coming up in their verandas.



I have been trying to go through some iNaturalist records and have created a collection project to monitor the possibility of the African Spur-thighed Tortoise being introduced somewhere into the southern US through escaped pet tortoises. These are powerful tortoises that can get over 100lbs and often escape captivity by burrowing or even bulldozing their way out of captivity.

The problem I’m having is getting identifiers to discriminate between obviously captive tortoises that people post and legitimate records of escaped or possibly feral tortoises found wandering in the wild. A lot of identifiers simply see a record of this species and automatically mark it as captive/not wild without considering the circumstances of the discovery. So the data are obscured by these records being marked as casual.

I’m not sure if that is helpful to your project design/implementation, but it is a problem I have run into that complicates monitoring.


Emerald Ash Borer documented in North Central Texas is a pretty big deal and caused quite a splash:

It was just a pretty green beetle to the observer, but as it was ID’ed as the Emerald Ash Borer, then The Forest Service and other interested parties took action:


An observation on iNat was the first one in Canada of Cydalima perspectalis

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I’ve started adding records to iNat of Russian Sage, a popular ornamental shrub in my area, which I’ve found in a few situations where it was clearly not planted. Others have been doing the same. The shrub might have potential to be invasive in the Southwest U.S. so I’m interested in documenting where it occurs in a wild state.

Ah but doing it through a collection project is exactly what I want :\ I made a traditional project with a plant list but the old option to automatically aggregate observations isn’t there…

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Surely it would be time-effective for Cal-IPC to pull up an iNat map of RG sightings of each species of concern once a year and see if they find any surprises.

You could also show them maps of California RG sightings for a few species, and see if they find something useful. And glancing at iNat maps of sightings outside California might help them monitor the approach of problem species.

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