Whales have long-distance relationships.
Bowhead whales enjoy long-distance relationships
Experts studied the seemingly random movements of bowhead whales in the Arctic Ocean and found that they synchronise dives with their fellow creatures up to 60 miles away.
Scientists analysed 144 days of diving records of 12 of the whales tagged in West Greenland and found two diving "in synchrony".
The duo - one female and another of unknown sex - were sometimes hundreds of kilometres apart but would closely time their dives for up to a week.
Professor Evgeny Podolskiy, of Hokkaido University in Japan, said: "The possibility of acoustically connected whales, which seem to be diving alone but are actually together, is mind-bending."
Although the whales were in each other's acoustic range, the researchers were unable to record the sounds of the animals to establish if they were interacting because it remains technically challenging.