ABSTRACT
Seed of most North American trees are dispersed by wind. Although around 30 of the tree genera have species distributed by animals, wind is mostly used by the genera with large numbers of species. Wind-dispersed tree seed are designed either as autogyros, plane-winged projectiles, or parachutes. Animals move viable seed away from trees incidentally in the course of consuming fruit and through sloppy predation. Tree-frugivor and tree-predator relationships are different in many ecological respects and therefore will be treated separately. Frugivors use the pulpy part of fruits as a source of nutrition. The degree and nature of their seed dispersal are influenced by food processing and ranging behavior. In contrast to frugivors, seed predators are after the seed's energy and nutrients. In the course of this pursuit, they may move seed away from parent trees, and some of these seed escape being eaten due to predator incompetence or over-enthusiastic hoarding.
