Who Eats Whom? A new site for searching iNaturalist feeding interactions

Hi everyone,

I have finished a working prototype of a site that allows you to search the common name of a species and figure out what it eats, based on iNaturalist feeding observations. You can check it out here: https://whoeatswhom.org/

My ultimate goal is to make a kind of global food web that users can manipulate to see how species are connected to others. I also want to introduce a more robust search mechanism (searching at higher taxonomic levels, at specific spatial scales, etc.).

It’s still a work in progress and pretty glitchy but I would love to know what the community thinks about it. Specifically:

  1. Are there particular communities that might find this information particularly useful/beneficial/interesting?

  2. What features would you add to the site?

  3. What are the most obvious bugs that need fixing?

  4. What do you think about the process of adding observations to the database? I know it’s cumbersome to add URLs to the two observations to match them…

Any thoughts/feedback would be greatly appreciated! I love this community and I’ve always thought it would be useful to centralize the interaction data you get in some of the observations. I’m applying for some grants to try and get funding to develop this further. If you have any feeding observations, please add them to the project!


Are there any particular fields you prefer we use to help this effort?


Great stuff! You may be interested in the previous discussion here, asking for something like this for the site: https://forum.inaturalist.org/t/add-interactions-to-species-pages/433

My main suggestion is to not limit yourself to observations from a single project, and to make use of the existing observation fields that record interactions.


Depending on the breadth of your use of “Eat”, you might be interested in the project I set up for wood-decay macrofungi; specifically aimed at trying to document the host range of different species



What’s behind the limitation to common names? Is it that one can only search for species, not higher taxa? I’d be interested in using scientific names as well as looking for interactions at the genus ir family level.


Right, yeah a next step will definitely be allowing users to search at coarser taxonomic scales (genus, class, etc.). It was just easier to set up the coding for common names of species, for now.


Good question. Yes the protocol for submitting to the project is here: https://www.inaturalist.org/projects/who-eats-whom/journal/86064-website-update

Basically, you need to upload two observations to the “Who Eats Whom” iNaturalist project: one of the “eater” and another of the organism being eaten. There are three Observation Fields associated with this project:

  1. Is the observation meant for the “eater” or organism being eaten?
  2. Is observation a special type of feeding interaction (pollinating, scavenging, etc.)?
  3. [MOST IMPORTANT] URL for the “partner” observation

Thanks @deboas! That’s a really useful thread. I went around and around about the right flow for incorporating observations. A lot of the existing projects focused on documenting interactions rely on the observer to supply the “partner” in the interaction (“interaction: eating → common milkweed”). The issue with that is that there isn’t a way to verify that the observer-submitted ID is correct. So that’s why I made a new project to feed into the website.

I would love to bring in existing observations from other projects in the future though if I can figure out a way to make sure the iNat community agrees on the ID for both eater and organism being eaten…

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Great idea! I started looking for observations I could upload… and realised that:

  • I have to know the organism being eaten to species level
  • both species need to have English common names
    …that complicates things a lot.
    I have a few observations of mantis eating… something. I can say Hymenoptera, but that’s about it. And not all Spanish insects (in case I get them identified) have common names.

Very interesting use case. Hmm. I don’t know a ton about mycology: anytime a mushroom is growing on a log in that way is the mycelia definitely obtaining nutrients from the log, rather than potentially just using the log to anchor itself/give it a place to live?

I could potentially add a new option for “special” feeding types that includes “fungal decomposition.” But a lot of times the mushrooms are growing on living trees, right? So is that parasitism instead or decomposition…? So much to think about! Would love to know what you and others think about this.

You don’t have to do the IDs yourself! You upload the observations to the iNaturalist project (https://www.inaturalist.org/projects/who-eats-whom). If the iNat community IDs them to research-grade at species-level they will go to the site.

Good point about some species not having common names. I just found a case where this happens (search “Who is eaten by” “Marbled Cellar Spider”). It looks like it just reports it as “undefined.” It should be a pretty easy coding fix for me to swap common name for scientific name if common name is undefined. Thanks!


This looks cool!

Also, I’m now humming “Who Eats Whom?” to the tune of AC/DC’s “Who Made Who”.


That would be nice. For example, the “Bird Food” project likely has many that would meet your criteria (e.g. this one of mine). It seems the key things you need are a field that identifies the interaction, and another field that links to the observation of the interacting species. Wouldn’t it be possible to search for those without constraining yourself to projects?

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I really love the idea of this - very useful for teaching biology. If you are aiming for this to be an international tool, it would be great if you could include scientific names. For international users, English common names are not shown in the inat interface, and you would have to google the scientific name first to find the input for your site.


This looks really neat!

  1. Does an observation like this belong in the project, even though the “eating” doesn’t occur until later? https://www.inaturalist.org/observations/188774219

  2. Seems like an opportunity to link up with https://www.inaturalist.org/projects/spotted-lanternfly-predation-in-the-u-s

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I agree that displaying the scientific name would be a welcome addition, but thankfully in the meantime inputting the common name in another language seems to correctly redirect (tried with French) [Edit: it works for scientific names too].

Honestly I’m grateful for any excuse to be more thorough and systematic with how I organise my observations. I’ll also keep a close eye on it since I was thinking about something similar with kleptotrichy and kleptoptily.

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That’s a great point. Adding scientific names will definitely be a key next step. I didn’t even realize that scientific names still brings up the corresponding English common name, for now, as @bvcz pointed out. That definitely wasn’t intentional but I’m glad it’s an ok workaround for now!

Good question. I think for now I’d like to limit observations to where the “eating” is present-tense, basically. E.g., it’s possible that the wasp didn’t end up ovipositing, or the eggs were infertile or something. If we start projecting into the future it could introduce some uncertainty.

Definitely a good idea to link up with that spotted lanternfly project, thanks for sharing that!


This could be really useful.

Looks like a huge job that has the propensity to blow out. I wish you a long life.

Couple of thought bubbles.

Plants get eaten by animals.
Plants get eaten by plants
Animals get eaten by plants.

Will you include decomposers and nutrient recyclers, or just macro organisms eating live stuff?

Common names - (rant alert) Common names are misleading and confusing.
The same name used for lots of organisms not even in the same order.
Lots of different names for the same organism.
So I’d hope you give preference and emphasize scientific names, at least be able to search on scientific name, at any level of Linnaean heirarchy.

I’d be inclined to include that. Justifying it from an evo / behavoural point of view, it’s a pretty good bet that the wasp will somehow eat the cicada, either tearing it to bits to take back to feed grubs, or laying an egg directly into it. (So in this case, feed it’s children). My thought is that your site is a repository of data, and researchers can filter out what they don’t like, same as I filter out plant obs with poor location data.

Nice project.

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This is awesome, but really needs to include scientific names, the requirement to use common names makes the thousands of species with no common name unsearchable

EDIT: well the idea is awesome, but all it does when I hit “search” is reload itself

EDIT 2: That is when it does anything, the search bar doesn’t even click now