How to find which species found in one place are not found within another place?

I thought it would be a good idea to try to fill out the species list of the city I’m currently living in. I was wondering if it would be possible to see which species have been observed in Ontario, but haven’t been observed in Guelph (the city), similarly to how one can see which species haven’t been observed by a certain user. Is there currently a way to do this?

Have a browse through here


A good link, but unfortunately I didn’t see any filters that do what I’m looking for. I found one that eliminated all observations within Guelph from the search results, but it didn’t eliminate all species that have been seen in Guelph from the search results.

The only way I can think to do this would be to search for all the species in Guelph, and then manually add the taxon ID for each to the URL to exclude them from the Ontario search, but obviously this isn’t really feasible.

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It’s a little brute force, there is no way I know of to limit it taxonomically but this url will compare the Wellington county checklist with the Ontario list✓&with=7219

So long as you know the place number which you can get to by going to see its url, you can replace Ontario which is the 7219 bit with something a little more viable like Hamilton couny, Halton etc.

I’m not sure why, but the mapping of the city of Guelph does not have checklists enabled, I could turn that on, but I can’t vouch for the accuracy of the map entered, even though it is 45 minutes from home.

@mws if you’re referring to species that have been observed on iNaturalist (and not all species ever found in a place), you have to break it into taxonomic chunks that have fewer than 500 descendants, but the Compare tool is otherwise great for this.

Here’s a link that compares bees that have been found in Ontario, but not in Guelph:

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This link will also get you to a filterable interface for species you haven’t observed. For example here are the amphibians that have been observed in Ontario that you haven’t observed:

One note on that approach, it may or may not matter to the user but it is not geographic specific. Thus it will exclude species which you have seen, but not in Ontario. So for example if you saw something in Quebec, but not Ontario, and your interest is in your Ontario, it wont be in that report.

It is basically the Ontario list filtered against everything you have ever seen in every place.

Good point. I misread the initial question as asking for the place comparison AND (separately) for comparison versus ones the user has observed.

This link is nice, though a bit hard to follow. Additionally, doesn’t it rely on people adding all the observed species to the checklist?

I’m currently living here, and the map is fairly accurate. There’s a few houses on the outskirts of the map polygon that aren’t included, but nothing major.

This feature is one I’m familiar with. I’ve used it a lot to find new lifer objectives, as well as monthly goals. Your amphibians example is also relevant to me, because I’m currently trying to observe all the frog species in Ontario. Only three left now.

This is very similar to what I’m looking for, though the 500 descendants sounds like a very frustrating limit. My goal is to get a list that tells me what I should be looking for. This doesn’t work very well if I have to select genus or family sized groups to compare.

Ontario has what is a very complete checklist done by NatureServe of species known to be in the province. You can see the completeness based on the fact there are roughly 9000 species on the checklist which have no records in iNat.

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It’s 500 descendants that have been observed in that search filter, so they are pretty big chunks really. What I do is make all the URLs and then save them somewhere, so it’s just one slightly frustrating set-up period.

You can also use the without_taxon_id to find “other” groups. So while there are too many vertebrates to show them all in one filter, you can query something like vertebrates but without birds.

OK. I used the API to generate species lists for both Guelph and Ontario then generated the list of taxa that have been observed on iNat for Ontario but not Guelph (over 10,000 species). You can then batch upload these taxa files to a list for yourself. I had to split it into 6 chunks since it didn’t like large uploads…it won’t let me share CSV files on the forum so you can private message your email if you want them.

Here’s the list that I already test uploaded:

Unfortunately this is a static list and enough of a pain that you probably wouldn’t want to redo this regularly.

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This might be the most useful link since it shows Ontario species in order of observations and filterable that are included in that static list:

Note that this might contain descendant taxa of higher level taxa so the list above will be the most accurate.

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Oh, 500 observed descendants is much better, thanks for pointing that out. The “without taxon id” also sounds great.

These are great, thank you ! I’ll send you a message about the CSV files.

Pretty sure this search query is also limited to 500 (?) results though (but definitely nice to be able to see the top observed to compare).

Yes, you’re right that the query on that page has the same 500 limit. The list is complete and has some search function with all 10K+ taxa shown but is not live updating.