Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Xinjiang Tianshan' has mentioned 'Birds' in the following places:
Occurrence Sentence Text Source
Among the vegetation colonizing the Tian Shan came, likely via birds from the east, the ancestors of what we know as the "sweet" apple.
Birds, of course, eat all manner of fruit.
But most birds eat seedsxe2x80x94a dietary feature not conducive either to the selection or spread of a fruit tree.
Sweet apples are often eviscerated by birds, but the seeds are frequently left in the empty shell of the pome.
The reason is that apple (and pear and quince) seeds are rich in cyanoglycosides, which are highly repellent, particularly to birds...