But many insects and animals use a sun compass.
"By chance, the sun compass does work very well under this circumstance," he added.
Experiments with the parrot fish (Scarus) have demonstrated a Sun compass reaction that may also occur in other fishes.
He and his colleagues set out to determine whether, in fact, Arctic shorebirds could be using a sun compass.
Given where the birds studied by Dr. Alerstam are flying, Dr. Able added, "it certainly makes some sense that these birds would be using the sun compass".
They have been studying cryptochromes, light-sensitive proteins that help regulate the daily rhythm of the body's cells, and how they help set the sun compass by which monarchs navigate.
So their internal clocks quickly become out of phase with local time, and this, Dr. Alerstam said, introduces errors in their use of the sun compass that result in an approximation of a great circle route.
Thus, T. longicornis shows wavelength specific behavior by using only one of its visual pigments for sun compass orientation.
The cores were oriented in-situ using an orientation device equipped with both a magnetic compass and a sun compass.
Furthermore, they point to a global navigational cue employed by off-trail ants, perhaps some sort of a sun compass.
Resetting the time of their circadian rhythm in activity with either an altered light:dark or diel temperature cycle also reset the chronometric mechanism associated with sun compass.
