The Migratory Habits of Arctic Terns
No, terns don’t move from Point A to Point B in a linear fashion. Terns loop back and forth, practicing an almost revisonary method of flight, moving up and down longitudal lines and across latitudes in helixical patterns. Their internal sonar, (which is sometimes compromised by the vagaries of civilization) and the power of magnetism pull them, push them, compel them in their flight patterns. Yet any little wind can often blow this small bird with its enormous wing-span, this avian marathoner covers more territory than any other migratory creature on the planet, off course.
Terns just can't seem to take a direct route to any where. Sometimes this penchant for side-trips and aerial loopy-de-loops is a delight as it brings unexpected vistas and new possibilities never considered to the tern.
Yet other times, these often spontaneous flights can lead to disaster – can distract the tern from her true goal. She flies here and there, first pursuing this direction, then that, following one pull, then another. She is never sure which direction to take. She starts off north, then turns southeast, only to turn west and loop back north again. Then she may suddenly stop, in mid-air, and float on the currents, pondering which direction to take. As she hovers in mid-air, she may search the sea for clues, and then suddenly – she swoops off to the west again - flap/flap/flap - and gliding again, she drifts off toward some ill-defined destination - guided not by goal or direction, but some mysterious pull that even she cannot identify. Or sometimes, she is guided not at all, but is merely moving at the whim of the air currents, allowing external forces to dictate her path.
Of course, terns are also quite ferocious and persistent when actually focused on a goal (for example, a juicy piece of fish, particularly shrimp – a tern favorite). And when they are sure of their purpose, they are swift and accurate.