Plantgranivory

Plant granivory is the ecological interaction in which animals feed on plant seeds, influencing plant reproduction and community dynamics. The term covers a broad range of seed-eating organisms, including small mammals such as rodents, birds such as finches and jays, and invertebrates like beetles and ants, with occasional involvement of gastropods. Seed predation can occur before seeds are dispersed (pre-dispersal granivory) or after seeds have been dispersed (post-dispersal granivory), and the relative importance of these stages varies by species and habitat.

Granivory can markedly affect plant population dynamics by reducing seed survival, altering germination rates, and shaping spatial patterns of recruitment. It can drive selective pressures on seed traits, such as coat hardness, chemical defenses, dormancy, and timing of seed production. Some plants exhibit mast seeding, producing large seed crops in synchronous years to overwhelm seed predators, while others rely on physical or chemical defenses to deter consumers. In many systems, seed predators also contribute to seed dispersal, either by caching seeds in hidden locations or by forgetting caches, thereby providing a potential if variable, dispersal service.

Interactions with seed dispersal are complex. Predation and dispersal can both limit or enhance plant fitness depending on ecological context, predator density, and the relative rates of consumption versus effective dispersal. Research typically uses seed removals, exclusion experiments, camera monitoring, and long-term demographic data to quantify granivory's impact on plant communities.

Evolutionary and management implications include understanding coevolutionary dynamics between plants and seed predators, and applying insights to conserve plant diversity, manage invasive species, and predict responses to environmental change.