Glossary Home Birds are an anatomical paradox. They are powerful enough to fly for miles, but very delicate because of the physical effort it takes to stay aloft.
Birds have hollow bones and are astoundingly light.
Once we have caught a bird in our mist nets, we have to delicately remove it and take various measurements as indicators of its condition. Above are two of the tools we use to take measurements. To the left are a pair of digital calipers and to the right is a special rulers. The calipers are used to measure the length of the beak and tarsus, or foot bone, to the nearest one-hundredth millimeter. We use the ruler to measure the length of our temporary captive's wings and tail to the nearest one-half millimeter.