Compiled by ‘Kostur’
'Increase your Knowledge'
Birds Find Their Way
Like NASA space
shuttles, birds have several back-up systems for orientation and
navigation that they can call
Landmarks are particularly important. Often birds circle a nest or
roost site before leaving as if refreshing their memory
of the geography of the place. They observe the position of the Sun
and crosscheck it with their biological clocks. If the Sun is behind
clouds, but a little blue sky is visible, they can detect the changing
angle of polarised light as the Sun crosses the sky and orientate using
that. Night flyers have the stars to guide them, and night migrants flying
in the Northern Hemisphere use the fixed position of the Pole Star to find
If the sky is overcast, there is another almost fail-safe system.
Thanks to tiny particles of magnetic material in their heads and necks,
birds can detect the lines of force that make up the Earth's magnetic
field. The lines rise at an angle to the Earth's surface, so, in
perceiving the angle at which lines intersect the ground, a bird can
pinpoint its position on the planet with considerable accuracy.
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