Scientists have finally understood the mechanisms guiding the monarch butterfly in its two thousand miles migration it goes through twice a year. The insects have a very accurate internal compass that guides them on their journey.
Every year at the end of the warm summer, millions of monarch butterflies fly across the United States to reach Mexico, over an incredible distance of more than two thousand miles. Experts from the University of Washington have taken a closer look at the journey of the insects, inspecting the way they orient themselves towards Mexico. It appears that their internal compass can determine the sun’s position on the sky, and thus the time of the day. In this way, the monarch butterfly can read this data and head in the good direction.
This information has been known to biologists for quite some years now, but the exact process of receiving this data and processing it has only now been unveiled. The experts have found that the monarch butterfly has an internal clock which is mediated by the clock genes’ natural rhythms. This timekeeping system is working in the antennae of the insects. After receiving the information, the data is sent to the brain for a thorough analysis and processing. The result is combined with information coming from the eyes of monarch butterflies.
According to Eli Shlizerman from the University of Washington,
“We created a model that incorporated this information — how the antennae and eyes send this information to the brain. Our goal was to model what type of control mechanism would be at work within the brain, and then asked whether our model could guarantee sustained navigation in the southwest direction.”
However, the insects do not turn the quickest direction for their desired path. When they are thrown off-course, the monarch butterflies have to use a certain separation point that allows them to decide whether they should turn right or left. Additionally, they will never cross this point which is in their field of vision when they have to alter their course. When they return in spring, the mechanism is simply reversed.
The numbers of the monarch butterfly have dropped over the last years because of the milkweed loss, which is the only food their larvae will consume. However, a recent study has shown that their population is on the mend.
The findings of the study were published in the Cell Reports journal.
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