Baihaba village sits on China's northwesternmost edge, where it occupies overlapping realms of identity, Erik Nilsson reports in Altay, Xinjiang.

Visitors giggle as they jiggle the plump rumps of Altay big-tail sheep in China's northwesternmost village, Baihaba. These creatures' bouncy backsides have become an endearing icon of the Xinjiang Uygur autonomous region's Altay Mountains. They appear on postcards, fridge magnets and plushies in souvenir shops. Viral videos of their waggling rears get millions of views online.

It's fun and funny. But it was once the serious business of survival.

This novelty was born of necessity, since, until recent decades, every precious calorie that villagers consumed was laboriously wrested from animals and potatoes.