Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Jeff Brewer on 29/09/2009 12:30:04
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Jeff Brewer asked the Naked Scientists:
I understand that monarch butterflies in North America take three generations to migrate from Canada to Mexico, and then three generations to migrate back again.
Do scientists yet understand how knowledge of the routes is passed on from generation to generation?
What do you think?
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Hi Jeff
Monarchs individually migrate the complete 4000km every season from the northern USA and Canada to Mexico, where they breed. Survivors then migrate back north. They make this journey by using the Sun as a compass to guide them. They link their body clocks to their visual systems (surprisingly using their antennae rather than their eyes to detect the light, according to a paper by Steven Reppert in Science just last week). This way, as the Sun goes across the sky during the day, they correct for the Sun's changing position relative to time in order to stay on course.
Chris