It's a mystery that has baffled scientists for many years.
Scientists have just cracked the code on the monarch butterfly, thanks to a model circuit.
The great migration of monarchs every year from Canada to Mexico is one of the most baffling things to scientists — how do these insects coordinate such a vast migration, they have wondered for years. Now, a team of biologists and mathematicians have figured it out, according to a University of Washington report.
The biologists were able to record directly from neurons in the antennae and eyes of the butterfly, figuring out that input cues depend on the sun. This provides the butterflies with an internal compass. Then, the mathematicians set about creating a model system of this internal compass to simulate it.
They created a timekeeping “clock” neuron for one control mechanism, and the other was the azimuth neurons from their eyes that monitor the position of the sun.
“Their compass integrates two pieces of information — the time of day and the sun’s position on the horizon — to find the southerly direction,” Eli Shlizerman, a University of Washington assistant professor, said in the statement.
“The location of this point in the monarch butterfly’s visual field changes throughout the day,” added Shlizerman. “And our model predicts that the monarch will not cross this point when it makes a course correction to head back southwest.
“In experiments with monarchs at different times of the day, you do see occasions where their turns in course corrections are unusually long, slow or meandering,” Shlizerman continued. “These could be cases where they can’t do a shorter turn because it would require crossing the separation point.”
The findings were published in Cell Reports.