Woodpeckers’ skulls are particularly sturdy to withstand the force of the blows as they hammer with their beaks. They are further aided by strong neck muscles to support their heads.

Scientists currently have two hypotheses to explain the homing flight of pigeons. Neither has been proved to the satisfaction of all the experts. The first hypothesis involves an “odor map.” This theory proposes that young pigeons learn how to return to their original point of departure by smelling different odors that reach their home in the winds from varying directions. They would, for example, learn that a certain odor is carried on winds blowing from the east. If a pigeon were transported eastward, the odor would tell it to fly westward to return home. The second hypothesis proposes that a bird may be able to extract its home’s latitude and longitude from Earth’s magnetic field. It may be proven in the future that neither theory explains the pigeon’s navigational abilities or that some synthesis of the two theories is plausible.