Seed predation

Granivores are found across many families of vertebrates (especially mammals and birds) as well as invertebrates (mainly insects);[2] thus, seed predation occurs in virtually all terrestrial ecosystems.

Seeds contain food storage organs (e.g., endosperm) that provide nutrients to the developing plant embryo (cotyledon).

Other physical defenses include spines, hairs, fibrous seed coats and hard endosperm.

These chemicals include toxic non-protein amino acids, cyanogenic glycosides, protease and amylase inhibitors, and phytohemaglutinins.

[1] Plants may face trade-offs between allocation toward defenses and the size and number of seeds produced.

Chili seeds in turn have higher survival if they pass through a bird's stomach than if they fall to the ground.

[9] Pre-dispersal seed predation takes place when seeds are removed from the parent plant before dispersal, and it has been most often reported in invertebrates, birds, and in granivorous rodents that clip fruits directly from trees and herbaceous plants.

[1] These predators belong to a diverse array of animals, such as ants, beetles, crabs, fish, rodents and birds.

Insect groups containing many pre-dispersal seed predators are Coleoptera, Hemiptera, Hymenoptera and Lepidoptera.

[1] The complex relationship between seed predation and plant demography is an important topic of plant-animal interactive studies.

In many cases this relationship depends on the type of seed predator (specialist vs. generalist) or the particular habitat in which the interaction is taking place.

However, in grassland habitat the seed predator had little effect on the plant population because it was safe site limited.