protects seed (= embryo) as it passes through birds digestive tract bird defecates seed with a supply of &quot;fertilizer&quot; (feces and urine) e.g., songbirds feeding on black cherries in forest&#151;trees grow best in light gaps (tree falls)&#151;birds visit these sites mammal dispersed : seeds have spines with hooks or barbs&#151;stick to fur of mammals&#151;moved to new location by locomotion of mammal e.g., squirrels eat acorns (seeds of oak trees), but may cache (store;
(tree; falls; ) (it; passes; through birds) (squirrels; may cache; store) (squirrels; eat; acorns) (birds; mammal dispersed; ) (songbirds; feeding; on black cherries in forest)
tree it squirrels squirrels birds songbirds
falls passes may cache eat mammal dispersed feeding
through birds
store
acorns
on black cherries in forest