A new global database is using photographs submitted by citizen scientists to map who eats whom in nature. The project, called Who Eats Whom, brings together feeding relationships from iNaturalist, a citizen science platform where people can share observations of plants, animals, fungi and other organisms, usually with a photograph and location. By early 2026, the new Who Eats Whom database already contained 1,863 species connected by 1,607 unique interactions. The American researchers hope to make scattered observations of predation, herbivory, parasitism and other feeding relationships more accessible for ecological research (Plos Biology, 22 September).
Since its launch in 2019, nearly two thousand observers from more than a hundred countries have contributed almost 14,000 observations of such interactions. Participants upload individual observations of consumer and food source, and then link them to one another. The website only uses photographs for which the species identifications have received sufficient support from the iNaturalist community.
Ecologists can use the database, for example, to identify previously undocumented or rare feeding relationships, find natural enemies, or explore food webs around invasive species. The authors do stress, however, that it does not constitute a representative overview of all feeding relationships.