group of buzzards rising in an updraft; pillar of buzzards
Refers to a flock of buzzards or similar raptors spiraling upward in a thermal, often seen during autumn migration. The literal gloss 'pillar of buzzards' describes the column-like shape.
In autumn, you can sometimes see a pillar of buzzards.
A large group of buzzards appeared in the sky, spiraling upward.
Compound of 鷹 (taka, 'hawk' or 'buzzard') and 柱 (hashira, 'pillar'), describing the column-like shape of the flock.