Truffle trackers: how dogs and humans help ecology and gastronomy in Oregon

Hunting for the underground fungus delicacy with dogs ensures ripe truffles and minimum environmental impact - and it's a great way to bond with a canine

Jason Swindle has already learned the best and hardest lesson that his dog can teach. "It's about trust. River does the craziest things when we're out here - she charges up cliffs or hillsides - and I have really just had to learn to trust her."

This trust is perhaps even sweeter than the prize she helps him find beneath the forest floor: truffles.