Fuzzy moss balls that colonise glaciers and move in perfect unison have puzzled scientists for decades. Now, thanks to some painstaking surveillance, they are finally giving up their secrets
16 December 2020
FEW have glimpsed them in the wild and you won’t see any in captivity. Yet the elusive glacier mouse – small, green and fuzzy – suddenly found itself an A-list celebrity earlier this year when reports of its antics became the antidote to a blizzard of bad news.
You may recall the tales of ice-dancing mice that travel in troupes and move with a synchrony worthy of the corps de ballet. If so, you will know that the mice in question aren’t actually mice at all. Purists might call them unattached moss polsters, supraglacial globular moss cushions or just plain moss balls. But when the Icelandic glaciologist JÓn EythÓrsson first brought them to the world’s attention in 1951, he dubbed them jökla-mýs (glacier mice) and it stuck. “They genuinely look cute, like a small furry creature – at least from a distance,” says Scott Hotaling, a glacier biologist at Washington State University.
Hotaling is one of the scientists who served up the latest instalment in the long-running saga of the glacier mice, which remain a riddle wrapped in a mystery. Those lucky enough to have encountered a colony in one of their remote icy haunts confess that they find them puzzling in many ways, not least their curious movements. Yet thanks to some painstaking sub-zero surveillance, these mossy blobs are slowly giving up their secrets.
Only in recent years have we begun to get the measure of glacier mice. That’s partly because they are rare, found only on select glaciers in Alaska, Iceland, …