Many organisms ranging from birds and bees to bacteria are known to have a magnetic sense that helps them navigate. But now it seems swine sense Earth’s magnetic field too – a finding that could help us win the fight against out-of-control feral pigs.
Pascal Malkemper at the University of Duisburg-Essen, Germany, and his colleagues made this discovery by observing more than 1600 wild boar in the Czech Republic, and more than 1300 warthogs in six African nations. Estimating the direction each animal was pointing in, the biologists found that, on average, they lined up closely with the north-south axis.
And it’s not just how they stand – they also found that wild boar beds face north or south, with a ridge at one end for it to rest its head. Altogether, the team suggests this shows these swine species have a strong sense of Earth’s magnetic fields.
“The fact that the animals align with the field lines suggests that they have a magnetic compass which they might use to navigate,” says Malkemper. Wild pigs can migrate over 50 kilometres between grazing areas. Perhaps a magnetic map of the landscape helps them find their way, he says.