Don't require `taxonIDReference`

[peterdesmet]

package.taxonomic currently has 3 required fields per taxon:

• taxonID
• scientificName
• taxonIDReference

For systems that want to infer the taxonomic scope for the observations (such as the IPT, see this discussion), it is possible to get the taxonID and scientificName, but not taxonIDReference. I think it would be better to relax the requirement for a taxonIDReference to support such systems.

[peterdesmet]

Maybe we also have to rename this term to reference or source to make it more broadly applicable (but still require a URL).

[peterdesmet]

Discussed with @kbubnicki. We suggest to:

Remove taxonIDReference

As it is currently only human readable. E.g. in the example dataset, the current value:

"taxonID": "5BSG3",
"taxonIDReference": "https://www.checklistbank.org/dataset/COL2023",

Is understandable to a human (COL2023 was used), but a machine cannot discern that both can be combined as {taxonIDReference}/taxon/{taxonID} to https://www.checklistbank.org/dataset/COL2023/taxon/5BSG3. It would be better if that URL was provided by the publisher in taxonID directly

Remove taxonID from observations

taxonID must currently be provided in observations (in combination with scientificName). The reasoning was to disambiguate homonyms in scientificName. However:

• Homonyms 1) are likely quite rare for camera trap datasets and 2) can be avoided by including the authorship in the scientific name (for homonyms). That should allow to uniquely link a scientificName in observations with the package.taxonomy using scientificName as the foreign key.
• Requiring a taxonID in the observations can be a burden for data providers (and thus adoption). They might revert to providing internal integers which isn't helpful
• Including a taxonID in observations (especially URLs, see point above) unnecessarily increases the file size for observations.

scientificName in observations should be sufficient, all other taxonomic information (taxonID, vernacular names, higher classification) can be provided (just once per taxon) in package.taxonomic

Don't require taxonID in package.taxonomic

To still support building a package.taxonomic (a required property) from the observations data (i.e. as in the IPT), we have to make taxonID an optional term (since it won't be provided any longer in observations). We can update the term definition to nudge users to provide a URL from a trusted source, e.g. https://www.checklistbank.org/dataset/COL2023/taxon/5BSG3