Dispersal by Animals (Zoochory)

Zoochory is dispersal of seeds and fruits by animals — birds, mammals and other creatures, including human beings, who all play an important role in moving plant propagules around, sometimes over very long distances. The textbook groups zoochory into three distinct mechanical devices. Hooked fruits carry hooks (e.g. Xanthium), barbs (e.g. Andropogon), or spines (e.g. Aristida) on their surface that snag onto the fur of passing animals or the clothing of people, hitching a ride until they eventually fall off somewhere new. Sticky fruits and seeds use a different attachment strategy: some develop sticky glandular hairs that adhere directly to the fur of grazing animals (e.g. Boerhaavia, Cleome), while others coat themselves in a viscid (sticky) layer that adheres to a bird's beak as it feeds — the bird later rubs its beak clean against a tree branch elsewhere, depositing and effectively planting the seed in a new location (e.g. Cordia, Alangium). Fleshy fruits, the third device, rely on being eaten rather than hitchhiking: brightly-coloured, conspicuous fleshy fruits (e.g. mango, Diplocyclos) are consumed by animals or people and later deposited, undigested, at a dist …