Invertebrate endozoochory: An overlooked pathway of seed dispersal

Seed dispersal is a key process in plant regeneration and persistence. While vertebrates such as birds and mammals are widely recognised as endozoochores, a growing body of evidence reveals that invertebrates also contribute meaningfully to seed dispersal through ingestion and defaecation. This review extends the prevailing vertebrate-centred paradigm, arguing that invertebrate gut passage is a recurrent, testable, and ecologically meaningful process. We synthesise current findings on invertebrate-mediated endozoochory across arthropods, gastropods, and other groups, highlighting their effectiveness, ecological relevance, and overlooked roles in shaping plant recruitment, especially in insular or fragmented systems. We adapt the seed dispersal effectiveness framework to invertebrate-mediated dispersal, identify key knowledge gaps, and call for systematic integration of invertebrates into seed-dispersal research and conservation planning.