As the crow flies

As the crow flies, similar to in a beeline, is an idiom for the most direct path between two points. This meaning is attested from the early 19th century,[1][2] and appeared in Charles Dickens's 1838 novel Oliver Twist:

We cut over the fields at the back with him between us – straight as the crow flies – through hedge and ditch.[1]

A crow flying across the terrain

Crows do conspicuously fly alone across open country, but neither crows nor bees (as in “beeline”) fly in particularly straight lines.[3] Crows do not swoop in the air like swallows or starlings, and often circle above their nests.[3]

One suggested origin of the term is that before modern navigational methods were introduced, cages of crows were kept upon ships and a bird would be released from the crow's nest when required to assist navigation, in the hope that it would fly directly towards land.[1] However, the earliest recorded uses of the term are not nautical in nature, and the crow's nest of a ship is thought to derive from its shape and position rather than its use as a platform for releasing crows.[1] It has also been suggested that crows would not travel well in cages, as they fight if confined.[4]