Scientist measures bird beak

Detailed Description
A scientist measures the beak, or culmen, of an American Avocet. Culmen length is frequently measured from the tip of the bill to the feather line.
Sources/Usage
Public Domain.
A scientist measures the beak, or culmen, of an American Avocet. Culmen length is frequently measured from the tip of the bill to the feather line.
Public Domain.