The story of animals surviving one of the harshest seasonal changes on the planet continues with the second episode of Yellowstone, The Toughest Spring, which airs on Wednesday 4 January at 9.00pm.
As winter turns to spring, temperatures rise and Yellowstone bursts into life. Beavers feast on new green shoots, baby bison take their first faltering steps, and grizzly bear cubs emerge from dens to explore this new green world.
But Spring is also a perilous time. Wolves are hungrier than usual after slim winter pickings, and rising temperatures melt the vast mountain snow pack, sending a million tons of water flooding into the rivers. Only the toughest will survive.
Presented by Kate Humble and Patrick Aryee.
Our picture shows an adult owl and two chicks in Beartooth Mountain
Yellowstone: The Toughest Spring (Episode 2 of 3) Airs on BBC Two on 4 January, 2017 from 9.00pm – 10.00pm