# Replace hybrid ranks with a hybrid\_level property **URL:** \ **Category:** Feature Requests\ **Created:** [January 29, 2026, 7:00pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172 "2026-01-29T19:00:46Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![cyanfox](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/cyanfox/32/35771_2.png) [@cyanfox](https://forum.inaturalist.org/u/cyanfox)\ **Post date:** [January 29, 2026, 7:00pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/1 "2026-01-29T19:00:46Z")
**Platform(s)**, such as mobile, website, API, other: All **URLs** (aka web addresses) of any pages, if relevant: [https://forum.inaturalist.org/t/species-search-doesnt-include-intergrade-observations/57768](https://forum.inaturalist.org/t/species-search-doesnt-include-intergrade-observations/57768) **Description of need** : The way hybrids are currently implemented is lacking. Because there are separate ranks for hybrids, hybrids can only be added for those ranks which have a hybrid counterpart (genus, species, subspecies, variety and form). This prevents things like family hybrids (like [Icteridae × Icteriidae](https://www.inaturalist.org/taxa/1124188-Icteria---Icterus)) and section hybrids (like [Rubus × Ursini](https://www.inaturalist.org/taxa/1383492-Rubus-ursinus---armeniacus)) from being added. And the search cannot distinguish between hybrids of different levels, such as an intraspecific hybrid between subspecies (most infrahybrids) and an interspecific hybrid between subspecies ([these ones](https://www.inaturalist.org/lists/4485547-Interspecies-infrahybrids)). For the issues with this, see the above bug report. **Feature request details** : Any taxon of the rank “hybrid” should be automatically changed to “species”, and its hybrid\_level set to 10 (the rank\_level of species and hybrid), though this can be changed manually if necessary. Any taxon of the rank “genushybrid” should be automatically changed to “genus”, and its hybrid\_level set to 20 (the rank\_level of genus and genushybrid), though this can be changed manually if necessary. Any taxon of the rank “infrahybrid” should be automatically changed to “subspecies”, and its hybrid\_level set to 5 (the rank\_level of subspecies, variety, form and infrahybrid), though both of these can be changed manually if necessary. For example, _[Anser anser domesticus](https://www.inaturalist.org/taxa/1122690-Anser-anser-domesticus---cygnoides-domesticus)_[× _cygnoides domesticus_](https://www.inaturalist.org/taxa/1122690-Anser-anser-domesticus---cygnoides-domesticus) will need a rank of variety and a hybrid\_level of 10. Non-hybrids should have their hybrid\_level set to 0 (not currently used as a rank\_level, and won’t be able to be used as one in the future if this is implemented). Hybrids between ranks that previously weren’t possible should be added. ---
**Author:** ![upupa-epops](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/upupa-epops/32/1972_2.png) [@upupa-epops](https://forum.inaturalist.org/u/upupa-epops)\ **Post date:** [January 29, 2026, 7:16pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/2 "2026-01-29T19:16:14Z")
I feel like the ideal situation would be that when you create a new hybrid, there are 2(+) taxon fields where you can select any taxa. Once you choose one, the other(s) must be of the same rank. ---
**Author:** ![rynxs](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/rynxs/32/22529_2.png) [@rynxs](https://forum.inaturalist.org/u/rynxs)\ **Post date:** [January 29, 2026, 7:41pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/3 "2026-01-29T19:41:54Z")
> [@upupa-epops](#): > > Once you choose one, the other(s) must be of the same rank. Unfortunately this does not work well for plants, where some groups have infraspecific × species combinations, e.g. _Asplenium_ × _inexpectatum_ (_A_. _rhizophyllum_ × _ruta-muraria_ var. _cryptolepis_) or more complex nothospecies situations like _Carex_ × _flavicans_, where nothovar. _flavicans_ is _C_. _aquatilis_ var. _aquatilis_ × _subspathacea_ and nothovar. _substans_ is _C_. _aquatilis_ var. _minor_ × _subspathacea_. ---
**Author:** ![upupa-epops](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/upupa-epops/32/1972_2.png) [@upupa-epops](https://forum.inaturalist.org/u/upupa-epops)\ **Post date:** [January 29, 2026, 7:53pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/4 "2026-01-29T19:53:37Z")
Now that I think about it, it doesn’t technically work for other taxa either. For example you could have a hybrid with Canada Goose and a domestic goose where you can’t tell if both Greylag and Swan Goose are involved (i.e. _Branta canadensis_ × _Anser_). However even though that option could theoretically exist now as far as I know, it doesn’t and so that example would be forced to [_Branta_ × _Anser_](https://www.inaturalist.org/taxa/508128-Branta---Anser). Looking at the species page for _[Asplenium × inexpectatum](https://www.inaturalist.org/taxa/170516-Asplenium---inexpectatum)_, it looks like the hybrid formula is presented as _Asplenium rhizophyllum × ruta-muraria_ so it seems like maybe the same curation rules are being used for plants as well? ---
**Author:** ![rynxs](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/rynxs/32/22529_2.png) [@rynxs](https://forum.inaturalist.org/u/rynxs)\ **Post date:** [January 29, 2026, 8:15pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/5 "2026-01-29T20:15:52Z")
I think the person who added the hybrid formula name just didn’t specify the variety. I edited the hybrid formula. We try to be as specific as possible with plants because there is a tendency for infraspecifics to gain momentum into becoming full species. I’m not familiar with your goose example so I can’t say how it compares, but hybrids in plants involving infraspecifics tend to be more significant than one might expect due to the aforementioned momentum. If you want to see some funny hybrid formulae, search _Asplenium trichomanes_, which contains a bunch of cryptic speciated lineages that all hybridize with each other and most other sympatric _Asplenium_. 40 taxa for the price of one species search! ---
**Author:** ![upupa-epops](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/upupa-epops/32/1972_2.png) [@upupa-epops](https://forum.inaturalist.org/u/upupa-epops)\ **Post date:** [January 29, 2026, 10:20pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/6 "2026-01-29T22:20:54Z")
Interesting, are there different hybrid names for hybrids of _A. rhizophyllum_ with different varieties of _ruta-muraria_? From my zoology perspective it seems strange to formalize that information as part of the nothospecies name definition rather than having it at a lower rank below the hybrid or even just in publications associated with the hybrid name. I’m curious if there are any examples of animals where multiple distinctive subspecies of one species hybridize with a second monotypic species. The closest example I can think of was the observation description of [this observation](https://www.inaturalist.org/observations/200480233) which refers to _Junco phaeonotus_ × _J. hyemalis dorsalis_, but technically _J. p. palliatus_ × _J. h. dorsalis_ would be more precise. Anyone using scientific names would usually just say _J. phaeonotus_ × _J. hyemalis_ rather than including subspecies since there’s only one subspecies of each species breeding where their ranges overlap as far as I know. ---
**Author:** ![cyanfox](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/cyanfox/32/35771_2.png) [@cyanfox](https://forum.inaturalist.org/u/cyanfox)\ **Post date:** [January 30, 2026, 10:23am UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/7 "2026-01-30T10:23:40Z")
That was a previous feature request of mine. [https://forum.inaturalist.org/t/list-parents-of-hybrids/46968](https://forum.inaturalist.org/t/list-parents-of-hybrids/46968) P.S. And I’d say there are some situations in which you’d want to have mixed-rank hybrids, like _[Setophaga coronata auduboni](https://www.inaturalist.org/taxa/509064-Setophaga-coronata-auduboni---setophaga-townsendi)_[× _setophaga townsendi_](https://www.inaturalist.org/taxa/509064-Setophaga-coronata-auduboni---setophaga-townsendi), which I wish hadn’t been deactivated. But the reason a mixed-rank hybrid is warranted in this case is due to _[Setophaga townsendi](https://www.inaturalist.org/taxa/145255-Setophaga-townsendi)_ being monotypic. I suppose such cases could be exempted from the general rule that mixed-rank hybrids aren’t allowed. But it seems chaotic. What happens if someone adds subspecies to such a monotypic species? Anyway, I don’t think having parents of hybrids listed should be the only way for iNaturalist to know something’s a hybrid. In the beginning, the parents will probably have to be added manually for at least some hybrids. ---
**Author:** ![upupa-epops](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/upupa-epops/32/1972_2.png) [@upupa-epops](https://forum.inaturalist.org/u/upupa-epops)\ **Post date:** [January 30, 2026, 3:38pm UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/8 "2026-01-30T15:38:04Z")
Aha thank you for this warbler example. And from the [flag discussion](https://www.inaturalist.org/flags/527769) on it, yes, the Curator Guide says that hybrids should be between taxa of the same rank. ---
**Author:** ![ericakeklak](https://avatars.discourse-cdn.com/v4/letter/e/9dc877/32.png) [@ericakeklak](https://forum.inaturalist.org/u/ericakeklak)\ **Post date:** [January 31, 2026, 5:57am UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/9 "2026-01-31T05:57:45Z")
The Curator Guide can be revised if the framework regarding hybrids is revised. > [@upupa-epops](#): > > I feel like the ideal situation would be that when you create a new hybrid, there are 2(+) taxon fields where you can select any taxa. Once you choose one, the other(s) must be of the same rank. > [@cyanfox](#): > > Anyway, I don’t think having parents of hybrids listed should be the only way for iNaturalist to know something’s a hybrid. In the beginning, the parents will probably have to be added manually for at least some hybrids. I do like the idea of allowing a user to select the taxa of the parents, but at some point we do have to consider organisms that: - do horizontal gene transfer (usually asexual organisms) - can have more than two biological parents - are hybrids of fertile hybrids (say a coywolf that is a cross between a “purebred” _Canis latrans_ and “purebred” wild _Canis lupus_ has a litter with a domestic dog…totally possible in the United States if the coywolf doesn’t eat the dog) - are a part of a ring species or something where it’s common for every organism to be a “hybrid” of “hybrids” of “hybrids” that are still fertile, such as certain salamanders - are polyploid and can have more than one possible option of the number of sets of chromosomes they receive from parents, which may affect how biologists classify a hybrid since some have more of parent A than parent B - (extremely hypothetical) are offspring of superfecund parents where some gene transfer between developing fraternal twins where at least one twin comes from a father of a different species. This is definitely not something that can be done on iNat unless someone genetically tests two members of the same litter. Most people who genetically test their observations are in microbiology or mycology and not general veterinary science where this is probably most likely to occur and be observable. However, it is important to consider - people’s familiarity with how hybrids work on iNaturalist, with some users reluctant to follow new best practice I can’t make any complaints about how such a revision to the hybrid framework would affect the computer vision model because it doesn’t work well for a lot of hybrids anyway. The best I’ve seen it do is identify hybrids in the birds of _Baeolophus_. The only intuitive way I could see this implemented is if every ID was of the taxa of an organism’s parents, where non-hybrids have redundant values for each parent because they are of identical kind. It is also extremely unlikely that we can actually do anything about implementing this framework since there are millions upon millions of existing iNaturalist observations, converting the data structure used to hold taxon IDs would take a long time and possibly add significant bloat to the size of the databases. If iNaturalist decides to make the father’s ID come before the mother’s ID as is typical when trying to describe the exact parentage of a hybrid (think mules vs. hinnies), then there would be a separation between the correct taxon ID for a mule (_Equus africanus asinus_ × _Equus ferus caballus_) than a hinny (_Equus ferus caballus_ × _Equus africanus asinus_) that didn’t exist before. If this is seen as a problem, especially if it’s too much work for something that doesn’t really matter, they can be lumped together as the same taxon and the order of parents would not matter. Regarding the original post up to and excluding inter-rank hybrids, I like the idea overall. This will add a column or two to some table somewhere in the database, but I can’t predict how much of a hassle it would be to have to expand storage to fit all preexisting observations with a hybrid level. It will also require a whole lot of taxon flags because people with very specific pet taxa will want to flag and add their even more granular hybrid where a more general hybrid exists and is not of great biological importance. If someone can accurately estimate how much a hybrid\_level property would cost to the back end, please reply because my vote depends on this idea being implemented efficiently. ---
**Author:** ![cyanfox](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.inaturalist.org/cyanfox/32/35771_2.png) [@cyanfox](https://forum.inaturalist.org/u/cyanfox)\ **Post date:** [February 2, 2026, 4:02am UTC](https://forum.inaturalist.org/t/replace-hybrid-ranks-with-a-hybrid-level-property/75172/10 "2026-02-02T04:02:08Z")
Another thing I’d like to add is that I also want the rank\_level of variety lowered (perhaps to ~~3~~ 4), and the rank\_level of form set to an even lower number (maybe 2), but of course, both should remain positive. Only subspecies should get to keep the 5. I want this done at the same time as the implementation of associating hybrids with their parents and the addition of the hybrid\_level propery, and the removal of the hybrid-specific ranks. By the way, I’d like the system to automatically assign hybrids to parents based on their scientific names or hybrid formulae. If an infrahybrid has varieties or forms assigned to it as parents, its rank should be set to that rank, rather than subspecies. The lowest rank prevails, which is why variety must be recognised as below subspecies and form must be recognised as below variety. Any hybrid which the system could not assign to parents should be automatically flagged, as it probably needs curator attention. The hybrid\_level property should be set according to rank\_level at which the parents diverge. If the parents have been set, it should be possible to do this automatically. When a curator adds parents to a hybrid, the system should require the parents to be the same rank as the hybrid, with an exception for eligible taxa of a higher rank. This exception only applies if the hybrid is below species. The excepted higher taxon must be species or below, and must not have any children at or above the rank of the hybrid. In other words, an eligible taxon cannot contain eligible taxa. However, the parents can’t all be eligible higher taxa. At least one must be the same rank as the hybrid. There’s no such thing as eligible lower taxa. The hybrid’s rank must be the same as its lowest parent. With the lowering of the rank\_levels for variety and form, and the removal of genushybrid, hybrid and infrahybrid, there would be no ranks with the same rank\_level. By the way, some plant species don’t have subspecies, only varieties. Under my proposal, these species would be allowed hybrids with subspecies, because they are monotypic as they don’t have subspecies, and variety is below, not equal, to subspecies. P.S. Variety should be rank\_level 4, not 3, because of the possibility of adding subvariety. P.P.S. [https://forum.inaturalist.org/t/adjust-rank-hierarchy-so-subspecies-variety-and-forma-are-not-at-same-level/60159](https://forum.inaturalist.org/t/adjust-rank-hierarchy-so-subspecies-variety-and-forma-are-not-at-same-level/60159)