Taken from the National Geographic
June 1991, Vol. 179, No. 6
Written by Michael E. Long
Pictures by James L. Amos
Despite frosted lenses placed over its eyes to deprive it of visual landmarks, a pigeon will still return to the vicinity of its loft.
Biologist Klaus Schmidt-Koenig supervises the release of pigeons in a field near Tubingen, Germany. In pioneer work published in 1958, he first documented the existence of a time-compensated sun compass in homing pigeons.