The team that documented magnetic alignment in dogs (a feat for which the researchers won an Ig Nobel Prize), fish in a barrel, and deer, have now done it for warthogs. Their new study is
“Magnetic alignment in warthogs Phacochoerus africanus and wild boars Sus scrofa,” Jaroslav Červený, Hynek Burda, Miloš Ježek, Tomáš Kušta, Václav Husinec, Petra Nováková, Vlastimil Hart, Veronika Hartová, Sabine Begall, and E. Pascal Malkemper, Mammal Review, epub June 19, 2016.
“Magnetic alignment (MA) results from the preference of animals to align themselves along the field lines of the geomagnetic field, a behavioural expression of a magnetic sense. MA is well documented for ruminants and might demonstrate a general magnetic sensory ability among artiodactyls. We measured body-axis alignment in 1614 foraging or resting wild boars Sus scrofa, 1849 wild boar beds, and 1347 warthogs Phacochoerus africanus, and found a highly significant north–south preference.”
Conor Gearin, writing in New Scientist magazine, interviews a team member, The interview carries the headline “Electric fields could help us wage war on destructive feral pigs“:
Which way does a pig point? The answer, it turns out, is north – or south.
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.