In 2021, 20 bonnethead sharks showed they use Earth's magnetic field to navigate

Twenty bonnethead sharks were given an unusual test at a Florida State University laboratory in 2021: could they tell where they were by reading Earth’s magnetic field? The young sharks, caught in the Gulf of Mexico, were placed in a tank where scientists recreated the magnetic conditions of different locations hundreds of kilometres away. When the field was altered to resemble a place about 600 kilometres south of where they had been caught, the bonnetheads turned in a direction consistent with heading back towards their original location. They did not show the same response when the researchers simulated a magnetic field found in the north. The scientists' evidence suggests that bonnetheads may use differences in Earth’s magnetic field as a kind of map, rather than relying on it only as a compass. The finding also raised questions about how sharks learn, store and use magnetic information as they move through the ocean.How scientists tested bonnethead sharks’ ability to read Earth’s magnetic fieldAccording to the study published in ScienceDirect, titled ‘Map-like use of Earth’s magnetic field in sharks’, the experiment involved 20 juvenile bonnethead sharks collected from Turkey ...