Should you find yourself crossing Llanberis Pass in North Wales, look out for these enormous boulders lying on the valley floor and the sheer cliffs from which they originated. As in most upland regions of the British Isles, Snowdonia was occupied by ice fields and glaciers during the last ice age, which culminated ~20,000 years ago. Ice carved these valleys, chiselled the mountainsides, and dragged the detritus – including these boulders – out towards the sea like a giant conveyor belt.

Viewed from the distant summit of La Pleureur in the Swiss Alps, the precipitous nature of the Matterhorn and Dent d’Herens are revealed in full. Glaciers and frost carved these peaks over the course of the Quaternary period, and continue to do so today. Yet it wasn’t until 1840 that the theory of ice ages was conceived and applied by Swiss naturalist Louis Agassiz.

I drew this little chap 'live' in McMurdo. Ironically, he was dead and long stuffed, living out eternity in a glass case upstairs in the Crary Lab. That same year I saw a live one, running alone through our camp on the Ross Ice Shelf during the 'night'. Where he was going and why I have no idea - perhaps nowhere and for no reason - but I sure was lucky to witness the scene.