It is possible using the unobserved_by_user_Id parameter in the observations view.
- if you do a species view, you are restricted to the 500 most frequently seen species unless you start filtering down (ie add birds or beetles etc)
- the ‘unseen’ is not geographic specific, it counts you as having seen it if you have seen it, but not in the location you specify.(so for example in the list below, Grey Kingbird will not appear, even though I have never observed one in Ontario, just elsewhere)
For excample this url shows all the birds reported from Ontario that I personally have not seen (or more accurately not recorded an iNat record for as I have actually seen some of them)
you can add additional filters for hrank and lrank equals species if you want to get rid of the genus level records.