Compass Orientation

The position of the sun or the stars in the sky can be used as a compass. The sun appears, due to the earth’s spin, to move through the sky from the eastern to the western horizon. At the equator, this path travels through the vertical azimuth; away from the equator the the sun’s path is not vertical, but the sun remains a strong directional cue except very near the poles.
To the earth-bound observer, the stars appear to be fixed on the inner surface of a rotating sphere. It’s as if we are standing in the center of ball which rotates around us; the stars are points of light on the inside of the ball. The celestial axis of rotation (the southern and northern points at which there is no apparent movement of the stars) correspond to the north star (Polaris) and the Southern Cross. Sailors, of course, used these points to help determine their position prior to the invention of modern navigational methods, such as global position systems. Animals are equally capable to cueing in on the sun or the stars and using them as navigational reference points.
The spin of the earth creates a problem; reference points may appear to move through the daily cycle of rotation. This apparent motion of the sun and stars is predictable on a daily basis and animals can compensate for it by integrating a clock mechanism with their navigational system. That animals do this is easily demonstrated by time-shifting animals in artificial light environments (habituating them to a day-night cycle that is a few hours displaced from the natural cycle) and then observing their orientation behavior when they are moved to a field situation (Dickerson and Dyer, 1996; Wiltschko and Wiltschko, 1999).
Long distance navigators, such as migrating birds, use geomagnetic cues to calibrate their compass. By using interacting cues, a more accurate course can be set than could be obtained by using any one cue.

Dickerson, J. and Dyer, F. 1996. How insects learn about the sun’s course: alternative modelling approaches. in Maes, P., Mafaric, J. J., Meyer, J., Pollock, J., and Wilson, S. Animals to animats. vol. 4. MIT Press, Cambridge, MA.
Wiltschko R, Wiltschko W 1999 The orientation system of birds - I. Compass mechanisms. Journal Fur Ornithologie 140: (1) 1-40