Solar storms of the kind responsible for the Northern Lights could have caused almost 30 whales to become stranded in the North Sea last year by affecting their ability to navigate, a study has found.
A total of 29 sperm whales died on beaches after becoming lost and trapped in shallow waters during early 2016.
New research has pointed towards disruptions caused by the solar flare-ups as a possible reason for this.
The findings were recently published in the International Journal of Astrobiology.
Whales are thought to navigate using the Earth's magnetic field, so disruptions triggered by random and abrupt solar storms may lead to disorientation.
In the open sea, scientists believe the animals switch to a more reliable navigation system if they realise they are heading the wrong way.
Many of the animals live around the Azores in the eastern Atlantic, which has deep and warmer waters.
The young males make their way north towards the polar region, attracted by masses of squid, when they are aged between ten and 15 years old.
Sperm whale strandings in the North Sea are rare, but younger bulls are more likely to be misled by solar storms because they have not yet learnt how to adapt to magnetic disturbances at higher latitudes.
This theory is backed by the fact the animals spend their early years in the lower latitudes, where disruptions by the sun are weak, so they lack experience of this phenomenon.
Solar storm disturbances to the magnetic field can last about one day and lead to short-term changes.
Researchers say the "naive" whales may therefore have become lost in the southern Norwegian Sea and become stranded in the shallow North Sea.
There were 29, mostly bachelor, sperm whales beached along coastlines of the UK, Holland and Germany between December 2015 and early January last year.
Dr Klaus Vanselow, from the University of Kiel, Germany, and his colleagues believe these could have been triggered by solar storms recorded over the same period.