Some people can do it, some bird species too. But never before had an invertebrate discovered that can navigate long distances on the stars. The Australian Bogong-Mot changes that: it uses a ‘star compass’ to fly about a thousand kilometers to a place where he has never been before. That writes an international biologogue team in Nature. This makes the performance of the moth more impressive than those of the manure beetle, which can also orientate itself on the Melkweg, but only for short distances.
That moths are crazy about light is no surprise: everyone knows the dramatic fate of moths flying in a candle flame. From other research Has been known for some time that moths can use the moon to orientate. According to some theories, moths would look for candlelight for the moon and thereby fly their downfall.
The current research team wanted to know whether moths can also distinguish the light from distant stars. In contrast to the moon, they can be seen throughout the month: much easier when navigating during a long trip. The biologists already discovered that the centimeters-sized Bogong-Mots (Agrotis Infusa) can also orientate with the help of the earth’s magnetic field. That, in combination with visual clues Such as moonlight or star light, she could help with their epic quest.
A few months in summer rest
The insects pupate into adult moths in the Australian spring and must then look for a cool hiding place before the version summer heat comes. They find them in high caves in the far southeast of Australia, near the coast. There they go for a few months in Summer Rust, the so -called ‘Estivation’. But before that they must be able to find that place, while they have never been there before (and will never return: in the Australian autumn they return to their birthplace to mate and die there).
The biologists caught the moths using a special light. The insects were then placed in a flying simulator, which could be adjusted. In this way a nocturnal sky with stars and without a moon could be shown, and the effect of the earth’s magnetic field could also be temporarily canceled out. These studies showed that the moths can indeed navigate on the stars and can even correct it for seasonal changes. The biologists also discovered some visual neurons in the Mottenbrein that are directly involved in the orientation on the star compass.
That the Bogong-Mot can also see really individual stars with its small composite insect eyes seems unlikely. Probably it is mainly the Milky Way that helps navigate. It is also known from manure beetles that they can push their poop balls in a straight line by orienting themselves on the clear lane of the galaxy. But, the biologists conclude, the beetles do that at most for a few minutes, and not in one specific direction – the enormous distance that the moths have to travel, many nights in a row, is much more impressive.