sun compass

sun compass

[′sən ‚käm·pəs]
(navigation)
A device which utilizes the shadow of a shadow pin, or gnomon, and a suitable dial to facilitate use of the sun for determination of direction.
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Monarchs use a time-compensated sun compass in their antenna to help them make their 2,000 mile migratory journey to overwintering sites.
Monarchs use a time-compensated sun compass in their antennae to help them find their way along the 2,000-mile migratory trek.
Alderney-like crystals could really have been used as an accurate optical sun compass as an aid to ancient navigation, when the Sun was hidden by clouds or below the horizon," the team wrote.
Earlier work by Reppert's group found that monarchs rely on a time-compensated sun compass to direct their navigation south.
The only criticism of this book is probably a minor error of editing, although an alarming one, during the discussion of animals using a sun compass as a navigation tool, which confidently states that "the sun is an ideal visual reference: every day it rises in the west and sets in the east.
uk/da/20090 on the Viking Sun Compass - both provide more fascinating information and ideas on this subject.
Some 50 years ago, biologists discovered that both honeybees and starlings use the sun in navigating, so monarch biologists speculated that butterflies, too, might find some kind of sun compass in their subjects.
The new study at the University of Massachusetts Medical School confirmed what had been suspected, that the creatures use an internal ``circadian'' clock as part of their sun compass.
Sun compass orientation in the meadow vole, Microtus pennsylvanicus.
Explaining that the birds must use the loft's infrasonic homing beacon to get their bearing before setting the direction for their return flight according to their sun compass, Hagstrum said, "I am a bit surprised that after 36 years I finally answered Bill Keeton's question to the Cornell Geology Department", adding that he is particularly pleased that he was able to use Keeton's own data to solve the mystery.
In general, this sun compass mechanism proposes that skylight cues providing directional information are sensed by the eyes and that this sensory information is then transmitted to a sun compass system in the brain," said Dr.
We believe we are on the trail of an important directional cue for migrating monarchs, in addition to their well-defined use of a sun compass," said Reppert.