For centuries, sailors and travelers have oriented themselves thanks to the stars and it is known thatmany birds also use this night map to make their movements. Now, a group of scientists from the University of Lund (Sweden), has discovered another animal that looks to the sky to orient itself: the African dung beetle.
He is tiny, and drags huge balls of feces to impress females. Once his treasure has been obtained, this animal mustget away from the manure heap as quickly as possible, because there a real battlefield is usually formed between the males of the same species, where anything goes to get the biggest ball and leave their opponents ‘out of play’. When night comes, these long-suffering suitors must be able to orient themselves to follow a straight line away from the manure heap.
The authors of the work, which is published in the journalCurrent Biology, they wanted to study the way in which the beetles guide themselves with the light of the moon so as not to get lost. To their surprise, they observed that even on moonless nights the animals kept their trajectories. Intrigued, they devised an experiment to find out what exactly was keeping the beetles on course. They designed a series of balls filled with sand and measured thetime it took each beetle to carry them from the center to the end of a given trajectory. They repeated the test both outdoors and inside a planetarium where they could manipulate starlight.
The results revealed that the animals took the same time to complete the path when they were outdoors than when they were inside the planetarium, under the light of the stars and the Milky Way. However, when their eyes were covered or in the sky only a few stars shone in low light, the beetles were lost or completed the journey with great difficulty. The researchers concluded that, under natural conditions,beetles do not use individual stars, but rather the entire band of the Milky Way that serves as a compass. Also, the Milky Way is much easier to see in the southern hemisphere, where the researchers conducted their experiments. The results also raise the possibility that other nocturnal insects use the Milky Way to orient themselves.
